25482 BSP-1414F TECHNICAL DRAINAGE REPORT
7 '
~
~ INLAND PACIFIC ENGINEERING, INC.
,
% Y
May 15, 1997 MaY 15
IPE W.O. #96111 4~
~ ~jEER
Spokane County Public Works H;
Development Engineering Services
1026 W. Broadway Avenue
Spokane, Washington 99260-0170
Attn: Ed Parry, Jr., P.E.
RE: Riverwalk 7th Addition (P1414-F)
Barker Road Improvements - Submittal
Dear Ed:
Enclosed please find the following as part of the submittal of the above referenced project for
your review and acceptance:
■ A completed submittal checklist.
■ 2 sets of bond copies and 2 sets of mylars of the Barker Road Improvements, stamped,
signed and dated by the Project Engineer, Todd Whipple and signed by the sponsor.
■ An approved design deviation.
■ Comments from Spokane County in a letter dated May 9, 1997 have been addressed as
follows:
Item 2. Our geotechnical engineer has written a letter to your office regarding
the 5' depth for soil logs. A faxed copy was sent May 12, 1997. A hard
copy is enclosed as promised.
Item 4a. The call-out for the drywell frame & grate has been changed from a
Type 5 to a Type 4 with a solid lid.
Item 4b. The call-out for the frame and grate on the concrete inlet in the pond has
changed from a Type 5 to a Type 2.
Document I961111rub5
707 West 7th • Suite 200 2020 Lakewood Drive • Suite 205
Spokane, WA 99204 Coeur d'Alene, ID 83814
509-458-6840 • FAX: 509-458-6844 208-765-7784 • FAX: 208-769-7277
4A
i~
Spokane County
May 15, 1997
Page 2
Item 8. The approved design deviation required is enclosed. (Thank you for
expediting that matter.) The note that was required as a condition of the
approval (regarding flow-testing of the gutter area with shallow grades)
has been written by Todd Whipple, reviewed by you, and added to the
plan set.
Item 12. An irrigation plan has been added to the plan set.
Item 13. Two (2) sets of bond copies have been included.
We are requesting acceptance of the enclosed plans. Your prompt attention to this submittal
would be greatly appreciated. Please call if you have any questions.
Sin erely,
Inl d Pacif #ineering Com any
~
Todd R. Whipple, P.
TRW/skm
Enc.
cc: Pacific Properties, Inc. - Doug Birch
File
Document1961111ru65
SPOKANE COUNTY TNTERIM RDA,D & DR.AINAGE
r
h
SUBMITTAL CHECKLIST
i ,
PROJECT # p1 4144 F DATE: 23' 12`j
PROJECT NAME: $AQKgK) --R t> - Zm'PRctj - ~ IVE"ALie-_ ~l> kJ •
PROJECT SPONSOR: TE1.9 ~040)&0 .
PROJECT ENGINEER: - W " ~ p ~ j ~ E TEI Al
(Road & Drainage Plans)
PROJECT SURVEYOR: - L • S. TEI # a 578 -&84C)
~
(Plat) '
PLEASE PROVIDE A RESPONSE TO EACH OF TSE FOLLOWING I'TEMS.
GENE]EtAL TTEMS '
YeSu,vo0r„A❑ 1. A signed "AGREEMENT TO PAY FEES" form has been submitted to Spokane County along with any
applicable plat fees, prior to any pre-design/presubmittal meeting
YeS0x013N/A❑ 2. I have a copy of, and have reviewed the most recent conditions of approval and any EIS/MDNS requirements
and conditions of approval have been incorporated in this plan submittal.
PROJECT DESIGN
YeSuNoOrv/A❑ 1. I have completed a minimum of one pre-design meeting with Spokane County Development Engineering
Services Engineers where• agreement was reached on drainage design approach. .
Yes LlrrouN/A❑ 2. I b.ave included the results of any geotechnical tescing that is required by the design approach to verify design
parameters.
YeSU,vo0N/A13 3. I have included any required pavement design calculations on new Public roadways as required by the
"SPOKANE COUNTY STANDARDS FOR ROAD AND SEWER CONSTRUCTION", latest edition.
YesuN00N/A❑ 4. The road and drainage plans comply with the"STANDARD ROAD PLAN" requirements for plan, profile, and
typical cross section elements contained in"SPOK.ANE COUNTY STANDARDS FOR ROAD AND SEWER
- CONSTRUCTION" latest edition except as allowed through approved design deviations.
,reSurvoON/A❑ 5. The drainage report incorporates the minimum requirements for a storm drainage analysis as noted in the GSM
and other items which are appropriate to demonstrate that the design meets all requirements of the Spokane
County Guidelines for Stormwater Management except as allowed through approveti design deviations.
Yesur,oON/A❑ 6. A complete drainage basin map with time of concentration paths shown has been included with the detailed
hydrology calculations. Drainage basin map shows tapograph, proposed drainage features, and correlates with
hydrology calculations. -
veSur,oON/A❑ 7. All applicable craffic signing requirements are met and have been incorporated'in the plan submittal.
veSE1HoOx1A❑ 8. I have included coPies of all aPProved DFSIGN DEVIATIONS which are required for this project.
YesUr,oON/A❑ 9. The plans and drainage report are stamped, signed, and dated, and contains, the applicable certification
statement.
,reSONoON/Au 10. I have included an adequate erosion control plan and applicable standard plan notes.
YCS0rr00N/A13 11. I have secured approvals from all applicable outside agencies such as fue districts where applicable and have
- included proof of their approvals..
veSELON/A❑ 12. I have provided an acceptable means for perpetual maintenance of street and drainage facilities that is acceptable
to Spokane County aad have secured and included copies of any required easements.
veSBNoON/A❑ 13. I have reviewed the plans, caleulations and other submittal data for completeness, accuracy alid consistency and
have submitted two copies of plans and (1) bound drainage report. Uckplatv 1.0/May95 1
~~-Iwn.-Jerstand that the requirements noted above are the minunum requirements necessary to perform a cursory review of the project
~plaris,.,and that additional information should be included with this submittal as necessary.
- ' •
1, iinderstand that this submittal will be checked for completeness prior to review, and that it will be retiuned for further information
if it is found to be incomplete.
I understand that this submittal will not be accepted for review (and placed on the review list) until all required information has
been submitted. Form completed by the responsible Engineer:
Company: I NL~J~ ~~arnr~PA~t~I
Address: ~D~ w~-~l ~1~E1~(~~ ZL~ S9~~ , I.LJA- 9°I ?.Dq
Zip code
Date:
FOR SPOKANE COUNTY USE ONLY
SUBMITTAL: Accepted for review.
Returned for submittal of the following:
GENERAL ITEM # :
PROJECT DESIGN # : RESUBMIT"TAL ITEM Form returned to: Company: Address: Date: By:
Spokane County Public Works Development Services
1/ckplacv 1.0/May95 2 '
7
. ~
,
May 12, 1997 INLAND PACIFIC ENGINEERING, INC. IPE W. O. #96111 Spokane County Engineers
- 1026 W. Broadway Avenue Spokane, Washington 99260-0170
Attn: Edward J. Parry, Jr. P.E.
Re: Riverwalk 7th Addition (P1414-F) Barker Road Improvements, Additional Soil Testing Clarification
Dear Ed: Obtaining a log of subsurface soil conditions to a depth of 5 feet below proposed "subgrade
elevation is an unnecessary expenditure of resources that would serve no useful purpose in
regard to this project, in our opinion. Excavation through surficial crushed rock revealed a
brown silty gravel at a115 test locations, which appeared to be native soils comprising the
upper, weathered portion of the Valley gravels we have encountered across the Riverwalk
development. Deeper excavation would likely encounter cleaner gravels, samples of which
would indicate greater pavement support characteristics, and thus a less conservative pavement
section than the one currently proposed.
We have previously provided an R-value, a resilient modulus, and 3 soil classifications for
samples of subgrade soils for the proposed Barker Road widening. These samples have been
obtained and tested in accordance with procedures that have been proposed by the County, and
accepted on numerous other projects. The sampling and -testing program to support design of
this road widening project is adequate, in out professional opinion. Logs of the soil profiles to
depths of 5 feet would not change the data recovered from the testing of these samples.
We would appreciate acceptance of the Barker Road plans without further delay. Please feel
free to call'if you have any questions whatsoever regarding this letter.
Sincerely,
Inl d Pacific Engin ring Company
_ • O
Je E. eterson, P.E.
Geotechnical Engineer ~ R131&19
y~
SZONAL
cc: Pacific Properties, Inc., Doug Birch EXPIRES 11 / 270'?
File ~ Document\96111LSFEET
707 West 7th • Suite 200 2020 Lakewood Drive • Suite 205
Spokane, WA 99204 Coeur d'Alene, ID 83814
509-458-6840 • FAX: 509-458-6844 208-765-7784 • FAX: 208-769-7277 '
MAY-14-1997 ~ 06:37 01150415 0213041402150514 P.03
w
.
♦
REQuEST Fo~ ~~~GN DMATIoN
DATE FEBSIIARY 14a 1997
)AD r1AME BAR~tER ROAD CRP1RiD ~ .
%lVIE OF PLAI' RIVEDFAI.R W ADAJTJ~0 . . - , PL-1 ~ P14I=
)ORESS OF BLDG ~ OF BLDG PR01~L"f ~ , BLDGt B9 S 34- T*~ R-43-.
;DERAi1STA1'E PROJECT # PROJEC'r LIlVIM .
EXISTIlVG CONDtTiONS: PROPOSED IMPROvEMENTS: .
~AD WIDTH 1 q' ± , Z= 12' ~.ANE_ ~111 BIKE PATH
'
)AD SURFACE ACP 4" ON 7"
VG. DAII.Y TRAFF'ZC 9800 AD'P 17.r 700 (20 YR - 3Z)
Curreac Traffic CouIIt Dtsign Year Tcafftc Couai
tOIECT DF..SCRIFTIOIv BARRER 80AD ZMPROvIImy-NTS INCLIJDE 16' OF NEH PAVFMEIdT WIDTH, TYPE B CURB ,
t EMM ACOU15-fTION ANp 2 1 op STnEg=l RATNAJZp 11TIT.TTY & SLOPE EAMGMT
g,A$T OF BA$KER RDpRjg •FR,oM_jLW Yox avEIP 1'0 19DJAPA aMEX• tOPOS."D DESIGv DEVIATION CR4SS SIAPES OF GKEATER 'i'HAtt 4.5Z FKAM SANCUT EDGE OF pAVEMM 1'0
GIIT7E8 LINE, ' LIIdTED TO AREA WI1'AIN 250' OP B!►RKER RpA'J./ INDIAKA AYENUE IN1'ERSECTION. ,
IS'FIFICATION: .
HATCEIV TO SAMOT ELEV16.9F Ea;TTNG ASPHALT L7 " T~ ~D&&Lo_pF SLOPE (2 - 4. SZ) AND
GDTTER SLOPE ( O,SZ) T4 ADJQST'LNG E.O.Y. ELEVA.TIONS QPffIL BdTM qBITERZA AB►E :MET. 1'HL FLAT ,
Sgj,ICOT LINE GMES I.N TaIS dRF.A (STATIONS 15+25 TO 18+50) F'ORCE A CHOICE BEIXEEN MAINTAINYNG ,
S-SLOPE OR GUTTF.'R SLOPE r NOT B=, WflILE FORCYNG A SDAO ABEA FOR DRAINACE SObTfl OF TflE II']'rEK- ,
JECTION IS _ ALSO A PRIO$L'~'Y - - fi j i ARE IN AN.AREA TW WILL BE.II
BY TRAFFIC SI.OWING DOWN TO TVRA EAS.T ON IND"NA AYEVE- 1W 1"ROYEILTM ARE BEING 24ADE PORTH
IANA' AT TSIS TIlKEr SO TRAFFIC WILL NOT BE 'r'RAVELING IN TU AREA0T1MII GR-TRAFFIC SYEIDS. ,
OF iFD
wBMITm:DBY ms DATE F~RQARY k4 1997
kDDRESS 707 N'ES,W A-r.-~ crrrI-204. SFQX.ANE" vA ZIP CODE 99204
v---- ---rR - - - -
sHONE ~f _1509L458-6840 (509) 4 8-6844 (FAg) '
••"400 ADMUMSrgAT1VE vARIANCE M OF S30.00 PAID 'r0 SPOKANE COUNTY
1026 w BROADwAY. sPOKAivE WA 99z60-O-i'r0 ~ NE (~~~'J600 FaX (509)324-3478
nyy ROLjT ~JNDS' /
l .KQ~.QV4~• ~}~~~WII.i. YOT HE RF~
i . / _
'~/1
T
t~~ ~ • ' ~ • vi~ii~ YV ;~d' ~ ' ~ LJA~
C~~CC~J~ ~ i . - • . .
MAY-14-1997 08:38 01150415 0213041402150514 P.04
,
. •
1.•y .
, DESIGI4 DEVIATION .
T#.tC, C4V4 Di. -Y74 04 C,Q M77bWZ!~O i~=4f>t 3
5,9 AWr' 9MISP ~ ~`~~~..~~:3~
pro,rca Appcv wkoaditions Noc wpFovea
.
) t ) t )
Project Manager Dacr
/~~GO.l~i~l~✓a it,v Gv7'T ~F Co.c!'D, T'o.v ~!.¢-y~ i~..~ E-a s~A~ ~ Y s sI9 ~At ow
.
. tprovcd Approved w/condiAOriS Noc .approved :
51,(3/f
) ( ) 7
praj Manapmeat~~eer Date
- ~ r ~ ~ /~.s~i-.-~.. f/'~~.~r,¢-~-•r-~.~~' .
~
PMved aPProvcd w/c=ditions Not ApprOved .
ppe~o~ ~ , Oace
POKANE COT4i i ENVVEC.Rf S
i ~ AT'ION: .
tQproved w/no condiaons Approved as recoumended above Not Approved ~
~
) . ( )
Spoka= Counry Eag.u= Dace
~ i
{u ,
. f • _
S P O K A N E O U N T Y
DIVISION OF ENGINEERING AND ROADS • A DIVISION OF THE PUBLIC WORKS DEPARTMENT
~ William A. Johns, P.E., County Engineer Dennis M. Scott, P.E., Director
May 9, 1997
Todd Wtupple, P.E.
IPE
Poug Birch
Pacific Properties
14410 Bel-Red Road
Bellevue, WA 98007 SUBJECT: P1414F - Riverwalk 7th Addition: Barker Road Improvements
Submittal Not Accepted at This Time
Gentlemen:
Thank you for your recenc submittal of the design package for this project. We have evaluated this submittal
for completeness, and we find that we are unable to accept this submittal at this time.
Our comments are enclosed on the attached sheet. Please ensure that all items which require additional acuon
are completed and are included in the next submittal.
Please contact Ed Parry at 456-3600 to discuss any questions you may have. Thank you.
Very truly yours,
William A. Johns, P. E.
Spokane County Engineer
P.E.
Edward J. P , Jr., P.E.
Plan Review Engineer
encLs: Plans (1 set - prints)
cc: project file
reviewer
1026 W. Broadway Ave. 0 Spokane, WA 99260-0170 •(509) 456-3600 FAX: (509) 324-3478 TDD: (509) 324-3166
l
~
REVIEW COMMENTS
SPOKANE COUNTY
DNISION OF ENGINEERING & ROADS
1026 W BROADWAY, SPOKANE WA 99260-0710
PHONE (509)456-3600 FAX (509)324-3478
SUBMITTAL 5 REVIEWER: Ed Parrx.
PROJECT _P 1414F DATE: 9 May 97
PROJECT NAME: Riverwalk 7th Addition
Bmker RQad Irr=ovements
N.B.: Since this project is governed by the edition of the Spokane County Standards for Road and Sewer
Construction (the "Standards", adopted 2 May 95, with an effective date of 15 May 95), these comments
are general in nature, and do not represent a listing of all items which may not be in compliance with the
Standards. The responsibility for ensuring compliance with the Standards lies solely with the Sponsor's
Design Engineer. EiI.L DISCREPANCIES MLTST BE ADDRESSED AND RESOLVED PRIOR TO
PLAN ACCEPTANCE
This Submittal:
PRO.EECT DESIGN
2. Geotechnical testing: The logs of the subsurface soil conditions, extending to at least 5' below the
proposed subgrade elevation, were not included in this submittal. This requirement is indicated under
"Soil Sampling Procedure" in the Pavement Design Parameters package previously provided.
4. Road and Drainage Plans:
a. The "type 5" frame and grate called out for the drywell in the traffic lane needs to be
coordinated with the drywell location. This detail (B-16) is for a grate to be usecl with a rolled curb;
please clarify.
b. The "type 5" frame and grate called out for the catch basin in the swale needs to be coordinated
with the catch basin location. This detail (B-16) is for a grate to be used with a rolled curb; please clarify
8. Design Deviations: The County Engineer's approval of a Design Deviation Request is needed when
the curb flowline grade is less than 0.5 We are processing your previous Design Deviation Request
for pavemetn cross-slopes exceeding 4.5 % to address this issue. A new Design Deviation Request for the
shallow flowline slopes is not needed.
12. How will the grass turf specified for the 208 swales be provided with adequate water? Irrigation plans
have not yet been submitted.
13. 2 print copies of the plans were not included in this most recent submittal.Please refer to Section
5.02.1. D of the County Standards (page 33)
REVIEW COIVIlVIENTS Page 2 of 2
9 May 97 PROJECT # _P1414F
REVIEW # 4
Other:
Sureties: Due to the changes in the road improvements from the initial strip-paving concept to the
current layout, it appears that the surety posted in late 1996 for the Barker Road improvements will need
to be revised. If the surety necessary for these improvements needs to be increased, that differential
amount will need to be posted prior to the County Engineer's acceptance of the plans. We will call with
the final amount of the surety necessary.
rJ
Parry, Ed
From: Parry, Ed
Sent: Tuesday, May 27, 1997 4:28 PM
To: 'Todd Whipple, P.E.'
Subject: P1414G - Riverwalk 7th: Barker Road irrigation plan
Importance: High
Todd:
Some questions & comments on the 1 st submittal of this plan sheet:
1. Are the Hunter Heads gear-driven or impulse rotary, or fmd -spray.?
2. These items should be addressed in the as builts:
a. Sprinkler layout should provide a flow between 0.2 and 0.75 in./hr
b. Swing joint connectors should be used to join sprinkler heads to the pipe
c. Antasiphon/backflow prevention valve location should be indicated
3. These items should be shown on the plan:
a. Manual shut-off valve location -
b. All pipes > 1" to be a minimum of SDR 21, CI. 200 (mains) or SDR 26, CI. 260 (laterals)
c. All pipes < 1" to be non-rigid CI. 200 Polyethylene
d. Casing should be provided for pipes crossing sidewalks
e. Valves should be kept out of the bottom of the pond (could be handled with a note on the plans)
f. Should note that minimum depth of burial should b e18" for mains, 8" for laterals
4. Only the irrigation system myiars need to be resubmitted. They are at the front desk for pick-up
These items are from the County's 1994 Interim Irrigation System guidelines. Please let me know if you have any
questions.
~ ft.Uf~" f K,04 4jz aAw4aP 5~4 w5
~'l.c
'd
~;--~-s
~
Page 1
~
7
ee4jECi\ b 1 JAA) q7
` INLAND PACIFIC ENGINEERING, INC.
,9z ~
May 6, 1997 ~ A~~( jZ.~f
IPE W . O . #96111 ~ ~
SPokane CountY Public Works DePartment
Development Engineering Services
1026 W. Broadway Avenue
Spokane, Washington 99260-0170
Attn: Ed Parry Jr., P. E.
Re: Riverwalk 7th Addition (P1414-F) Barker Road Improvements; Pavement Design
Dear Ed:
In response to the comments received by your off'ice in a letter dated April 30, 1997, the
attached calculations provide the documentation for the revised pavement design for the above
referenced project. The exhibit drawing included in this package documents that the sample
was obtained at a stated location and submitted to Pavement Services, Inc. The Resilient
Modulus value of the sample ranged from 22,885 psi to 45,587 psi (see attached letter). The
average of the two lowest values, 23,004 psi was used as a conservative estimate for the
pavement design.
The design parameters used for the pavement section have been coordinated with the
parameters in the Spokane County Interim Pavement Design Parameters (May 1995) as
requested. There has been some discussion between the County and our off'ice staff regarding
the Drainage Coefficient used in the Pavement Design program, DARWin. Because the
County does not provide a parameter for the Drainage Coefficient for ACP, leaving it to the
discretion of the design engineer, I chose a factor of 1.2 per the DARWin notes attached.
Although these notes are provided to you, it should be noted that we also referred to the
WSDOT Pavement Design Guide, AASHTO - Guide for Design of Pavement Structures,
1993, Volumes I and II, to provide background on the Drainage Coefficient and the use of
1.2. Please note that these documents support our original decision to use 1.2 as the correct
parameter.
You have dictated to my staff that the coefficient of 1.0 SHALL be used. I personally and
professionally object to you as an agency reviewer dictating design guidelines that are to be
sealed by myself. Against my better judgement and recommendations, Pacific Properties has
directed IPEC to submit using the 1.0 coefficient " just to get the plans approved",
therefore, we are submitting this design to you with a coefficient of 1.0. I want to make it
clear that this change was requested by the Sponsor, so that we do not have to endure another
Docuwnt196111 Ipvmtde.O
707 West 7th • Suite 200 2020 Lakewood Drive • Suite 205
Spokane, WA 99204 Coeur d'Alene, ID 83814 509-458-6840 • FAX: 509-458-6844 208-765-7784 9 FAX: 208-769-7277 .
Spokane County
May 6, 1997
Page 2
shut down for 7 weeks while you try to figure out this thing or that. By using your required
coeff'icient of 1.0 rather than the submitted 1.2 the resulting section for Barker Road is 5"
ACP on 9" CSTC rather than the 4" on 8" that I feel is absolutely acceptable for the location
and valley gravels encountered. All supporting calculations as required for the pavement
design are enclosed.
We are expecting approval of these plans immediately so that construction can begin ASAP.
As it has taken entirely too long to get these plans approved/accepted already, any additional
minor questions regarding this design should be handled over the phone, please call either
myself or Susan Murphy at 458-6840.
Sincerely,
Inland Pacific Engineering Company
,
t
. ,
odd R. Whipple, . E
TRW/slan
Enc.
cc: Dennis Scott, Director of Public Works, Spokane County
Pacific Properties, Inc., Doug Birch
file
~ wa
c~►o r~
'
`IlJre . 3-
~o R~~~ ~
~St~NAL~
EXPIRES 9/24/
Dvcument 19061111 pvmtdu3
c
1993 AASHTO Pavement Design
DARWin(tm) Pavement Design System
A Proprietary AASHTOWARE(tm)
Computer Software Product
Flexible Structural Design Module
Barker Road N. of Mission
Flexible Structural Design Module Data
18-kip ESALs Over
Initial Performance Period: 6,114,056
Initial Serviceability: 4.2
Terminal Serviceability: 2.25
Reliability Level 90
Overall Standard Deviation: .45
Roadbed Soil Resilient Modulus (PSI): 23,004
Stage Construction: 1
Calculated Design Structural Number: 2.99
Page 1
,
Specified Layer Design
Struct. Drain.
Coef. Coef. Thickness Width Calculated
Layer Material Description (Ai) (Mi) (Di) (in) (ft) SN
1 AC N .d2 'I b -36 1-.fa
2 CSTC .14 .95 9 36 1.20
Total - - - 14.00 - 3.30
Page 2
Rigorous ESAL Calculation
Performance Period (years): 20
Two-Way Daily Traffic (ADT): 9,800
Number of Lanes In Design Direction: 1
Percent of All Trucks In Design Lane 100
Percent Trucks In Design Direction 50
Growth: Simple
Percent Annual Average Initial Truck Annual % Growth Accumulated 18K ESALs
Class of ADT % Growth Factor (ESALs/truck) in Truck Factor over Performance Period
1 1 3_~b UUUU3 u 29
2 86.48 3.5 .0002 0 8,250
3 5 3.5 .02 0 47,696
4 .02 3.5 2.57 0 24,516
5 .5 3.5 1.5 0 357,721
6 .5 3.5 1.8 0 429,266
9 5.5 3.5 2 0 5,246,579
Total 100.00 - - - 6,114,056
Page 3
Barker North of Mission - Northbound Lane ' Barker North of Miss'•
July 15-19,1996 •
Day Time Count Day Time Count Day Time Count Day Time Count Day Time Count Time Average
Tues 0 41 Wed 0 28 Thurs 0 37 Fri 0 47 0 38
Tues 1 27 Wed 1 24 Thurs 1 15 Fri 1 26 1 23
Tues 2 11 Wed 2 11 Thurs 2 30 Fri 2 18 2 18
Tues 3 15 Wed 3 21 Thurs 3 18 Fri 3 11 3 16
Tues 4 37 Wed 4 28 Thurs 4 17 Fri 4 16 4 25
Tues 5 106 Wed 5 108 Thurs 5 104 Fri 5 79 5 99
Tues 6 167 Wed 6 175 Thurs 6 185 Fri 6 135 6 166
Tues 7 181 Wed 7 161 Thurs 7 181 Fri 7 180 7 176
Tues 8 174 Wed 8 157 Thurs 8 179 Fri 8 187 8 174
Tues 9 185 Wed 9 169 Thurs 9 183 Fri 9 199 9 184
Tues 10 256 Wed 10 220 Thurs 10 198 Fri 10 266 10 235
Tues 11 254 Wed 11 255 Thurs 11 248 Fri 11 260 11 254
Mon 12 324 Tues 12 288 Wed 12 276 Thurs 12 293 Fri 12 165 12 269
Mon 13 290 Tues 13 264 Wed 13 296 Thurs 13 269 13 280
Mon 14 303 Tues 14 315 Wed 14 293 Thurs 14 310 14 305
Mon 15 335 Tues 15 320 Wed 15 311 Thurs 15 352 15 330
Mon 16 402 Tues 16 390 Wed 16 431 Thurs 16 433 16 414
Mon 17 417 Tues 17 414 Wed 17 427 Thurs 17 446 17 426
Mon 18 309 Tues 18 334 Wed 18 355 Thurs 18 323 18 330
Mon 19 218 Tues 19 232 Wed 19 236 Thurs 19 251 19 234
Mon 20 239 Tues 20 223 Wed 20 215 Thurs 20 203 20 220
Mon 21 178 Tues 21 181 Wed 21 150 Thurs 21 173 21 171
Mon 22 121 Tues 22 98 Wed 22 82 Thurs 22 98 22 100
Mon 23 55 Tues 23 65 Wed 23 55 Thurs 23 43 23 55
4540
.Y,i
Barker North of Mission - Southbound Lane Barker North of Mim
July 15-19,1996 •
Day Time Count Day Time Count Day Time Count Day Time Count Day Time Count Time Average
Tues 0 34 Wed 0 0 Thurs 0 43 Fri 0 31 0 36
, Tues 1 26 Wed 1 0 Thurs 1 24 Fri 1 20 1 23
Tues 2 19 Wed 2 0 Thurs 2 22 Fri 2 21 2 21
Tues 3 25 Wed 3 2 Thurs 3 25 Fri 3 16 3 22
Tues 4 57 Wed 4 2 Thurs 4 47 Fri 4 33 4 46
Tues 5 99 Wed 5 4 Thurs 5 95 Fri 5 71 5 88
Tues 6 268 Wed 6 16 Thurs 6 259 Fri 6 257 6 261
Tues 7 392 Wed 7 34 Thurs 7 349 Fri 7 343 7 361
Tues 8 315 Wed 8 30 Thurs 8 317 Fri 8 316 8 316
Tues 9 303 Wed 9 26 Thurs 9 280 Fri 9 283 9 289
Tues 10 290 Wed 10 28 Thurs 10 287 Fri 10 369 10 315
Tues 11 340 Wed 11 35 Thurs 11 294 Fri 11 331 11 322
Mon 12 326 Tues 12 310 Wed 12 37 Thurs 12 288 Fri 12 148 12 268
Mon 13 315 Tues 13 289 Wed 13 38 Thurs 13 270 13 291
Mon 14 374 Tues 14 284 Wed 14 46 Thurs 14 306 14 321
Mon 15 409 Tues 15 422 Wed 15 39 Thurs 15 431 15 421
Mon 16 443 Tues 16 429 Wed 16 382 Thurs 16 400 16 414
Mon 17 362 Tues 17 423 Wed 17 509 Thurs 17 415 17 427
Mon 18. 340 Tues 18 204 Wed 18 296 Thurs 18 285 18 307
Mon 19 214 Tues 19 8 Wed 19 217 Thurs 19 206 19 212
Mon 20 209 Tues 20 7 Wed 20 192 Thurs 20 219 20 207
Mon 21 170 Tues 21 8 Wed 21 133 Thurs 21 147 21 150
Mon 22 103 Tues 22 11 Wed 22 80 Thurs 22 91 22 91
Mon 23 48 Tues 23 5 Wed 23 50 Thurs 23 50 23 49
5259
. • • ~
Overall Drainage Coefficient, Cd
The drainage coefficient, Ca, incorporates the effect of drainage on rigid pavement life. The effect of
drainage on pavement performance is a function of the quality of drainage (i.e., the time required for the
pavement to drain) and the amount of time during the year that the pavement structure is exposed to
moisture levels approaching saturation. It is up to the design engineer to determine the relative levels of
each of these values for the specific conditions being considered for design. The quality of drainage
depends on the permeabilities of the base and foundation materials, the design of the structural cross
section, and the presence of edge drains. The amount of time during the year that the pavement will be
exposed to near saturation levels is a function of precipitation and evapotranspiration characteristics that
are inherent to a particular climatic region. Guidance on the selection of the drainage coefficient is
provided in the following table:
Percent of Time Pavement Structure is Exposed to Moisture Levels Approaching
Saturation
Quality of Less Than Greater Than
Drainage 1% 1- 5% 5- 25% 25%
Excellent 1.25 - 1.20 1.20 - 1.15 1.15 - 1.10 1.10
Good 1.20 - 1.15 1.15 - 1.10 1.10 - 1.00 1.00
Fair 1.15 - 1.10 1.10 - 1.00 1.00 - 0.90 0.90
Poor 1.10 - 1.10 1.10 - 0.90 0.90 - 0.80 0.80
Very Poor 1.00 - 0.90 0.90 - 0.80 0.80 - 0.70 0.70
Where:
Quality of Drainage Water Removed Within
Excellent 2 hours
Good 1 day
Fair 1 week
Poor 1 month
Very Poo[ Water will not drain
Ref: 1993 AASHTO Design Guide, Part I, Section 1.8, p. I-27.
1993 AASHTO Design Guide, Part II, Section 2.4.1, p. II-22.
~ y
Memorandum
Date: May 12, 1997
To: Project File
From: Development Services (Ed Parry, P.E.)
Subject: P1414F - Riverwalk 7th Addition; Barker Road Design
Telephone Conversation with Todd Whipple Regarding Todd's Letter of
May 6, 1997
1. Todd called today (May 12, 1997) to discuss the letter he had sent on May 6th.
2. In the course of our conversation, Todd revealed his reasons for continuing to use a 1.2
coefficient to modify the strength of the asphalt pavement surface layer of the pavement section:
A. Other references indicate that a drainage coefficient is to be used. When asked to
specify the references, Todd noted that the gravel road design method specifically requires the use
of a drainage coefficient to modify the strength of the surface layer.
B. Todd feels that the .95 drainage coefficient for the strength of the base and subbase
layers was too conservative for the drainage characteristics of the area that he anticipates. Todd
stated that he was trying to "back into" a pavement section that he felt was reasonable for the
anticipated conditions. Todd stated that he had worked the design out by hand, and found that the
use of a 1.2 factor for the ACP layer would result in the design he felt was reasonable.
C. Todd stated that the DARWin pavement design program allowed the modification of
the ACP layer, so he made the modification at that point in the design process.
D. Todd did not want to pursue approval of a Design Deviation Request, based on his past
experiences with that process, and the tight time line this project was being put under.
Todd said that he would send a written explanation of his design approach to this pavement
section.
t .
P1414F - Riverwalk 7th Addition; Barker Road Design
Telephone Conversation witb Todd Whipple
Regard.ing Todd's Letter of May 6, 1997
Page 2
3. I told Todd that I although I could understand his evaluation of the site conditions, I most
definitely did not consider the design approach or the methods he used to get to the pavement
section design to be in keeping with good engineering practice:
A. I told Todd that if he had called me, I would have been more than happy to discuss his
perspective on this design, and to assist in finding a quick way to get the issue of the base/subbase
drainage resolved. I told Todd that there have many occasions where I have personally hand-
carried a Design Deviation Request through the system for approvals; in some cases, same-day
approval had been obtained.
B. I told Todd that the situation he has with the software is very much like the data entry
for sheet flow length in the TR-55 drainage program by Haestad. That program allows the blanket
use of up to 300' for a sheet flow component in the time of concentration calcs, and many
engineers have used 300' even though the slope and contours, or length of the flow path won't
support that assumption. I told Todd that using a particular value "just because the program allows
it" is not acceptable - the Engineer is still responsible for using the software in accordance with
the method upon which the software is based.
4. Todd apologized for the tone of his letter. I told Todd that I have some very serious concerns
about that letter now remaining as part of the public record. My concerns are based in the effect
this letter will have on both my personal and professional reputation, and my career at the County.
Todd agreed to send a written apology to me, as well as a letter explaining his apology to the other
parties receiving his letter. I understood him to say that he would not provide a notarized
statement that the letter had been purged from the file, and he said he would not provide a written
statement, from other recipients of his original letter, to the effect that they had received a copy
of the apology.
5. I told Todd that I have drafted letters to respond officially from the County on the technical
issues, and to respond personally about the tone of his letter. I told Todd that 1 would
a. Await his written apology;
b. Confirm with the other recipients their receipt of the written apology; and
c. Await his written explanation of his approach to the design of the pavement section,
before I proceeded with any other action in this matter.
6. This further explanation from Todd leaves me with a serious professional obligation. Knowing
in more detail how he is looking at the design of this pavement section, I am concerned that he
believes that he can rely on references (gravel pavement methods) that are not appropriate to the
location as justification of his design approach.
P1414F - Riverwalk 7th Addition; Barker Road Design
Telephone Conversation with Todd Whipple
Regarding Todd's Letter of May 6, 1997
Page 3
I am also concerned that he feels it is appropriate to rely on an apparent bug in the
software to justify his approach, regardless of the requirements and limitations of the method. He
appazently is still espousing this philosophy even after being informed that is not an appropriate
use of the software.
I felt before my conversation with Todd that there was a potential question about Todd's
professional competence and the ethics of his behavior in this matter. I now feel that there is a
very real problem about professional ability with respect to properly utilizing an appropriate
method to design a pavement section in a particular location, and a problem of ethical behavior
with respect to the use of the software available to complete that design, as well as the detrimental
effect of his correspondence on my personal and professional reputation.
These all appear to be issues which may be seen as a violation of RCW 18.43.105(2) and
WAC 196-27-020(3)(b), which require an Engineer to be truthful and objective in professional
reports. This information now places me under the requirements of WAC 196-27-020(d) to report
this situation to the State P.E. Board.
22 May 97: Ten calendar days have passed, and I still have not received the written apology Todd
promised. Todd told me this morning that he would work on it this afternoon
y
w
~
s`
~
S P O K A. N E , . C O U N T Y
DIVISION OF ENGINEERING AND ROADS • A DIVISION OF THE PUBLIC WORKS DEPARTMENT
William A. Johns, P.E., County Engineer Dennis M. Scott, P.E., Director
September 26, 1996
Todd Whipple, P.E.
IPEC
Doug B irch
Pacific Properties, Inc. ,
14410 Bel-Red Road
Bellevue, WA 98007
SUBJECT: P1414F - Riverwalk 7th Addition
Submittal Accepted
Gentlemen:
We have conducted a general evaluation of your recent submittal for this project, and we find
that with the exception of the improvement plans for Barker Road, this submittal appears to meet
the minimum standards of the Spokane County Standards for Road and Sewer Construction
("Standards"). We are therefore able to accept your plans and drainage calculations for those
portions of this project other than Barker Road.
Although you have submitted preliminary road plans, and have already posted a surety for the
Barker Road improvements, I expect that you will pursue the design of these improvements so
as to obtain the County Engineer's acceptance no later than November 15, 1996. If these plans
have not been accepted by the County Engineer's Office by this date, then any construction
permits for work in the public right of way will expire. The permit required for the work on
Mission Avenue will be worded to reflect this condition.
I am enclosing a sepia print of your approved road and drainage plans for this project: the
originals are on file at the Public Works Department. The approved drainage report is also on
file at the Public Works Department. In accordance with Section 5.02.D of the Standards,
this acceptance is valid until August 20, 1999. If the facilities are not constructed, you may
request an extension of the acceptance for and additional two years; the plans shall be revised
prior to granting the extension.
Please note:
1. The County's acceptance of this submittal does not relieve the sponsor or his agents
from any liability related to portions of the design that are not in conformance with the
Standards, or which do not follow good engineering practice.
1026 W. Broadway Ave. 0 Spokane, WA 99260-0170 •(509) 456-3600 FAX: (509) 324-3478 TDD: (509) 324-3166
w
.w
Todd Whipple, P.E.
Doug Birch
P1414F; Submittal Accepted
September 26, 1996
Page 2 of 2
2. All permits and notifications necessary prior to construction are the responsibility of
the project sponsor and/or his assigned agents; and
3. The County will not accept the improvements to be constructed under this project until
(a) all construction documentation and certified Record Drawings have been submitted and
accepted; and (b) all construction deficiencies noted in the County's Acceptance Inspection have
been corrected. Sureties posted construction performance and construction inspection services
will not be released until these items have been accomplished.
- Please be advised that if you construct the road and drainage facilities without posting surety,
the plat cannot be finalized until either (a) the road and drainage facilities are constructed and
accepted, and the roads established by the County Commissioners; or (b) adequate surety for
any remaining work has been posted.
If you have any questions, please contact Ed Parry at 456-3600. Thank you.
Sincerely,
G
/64illiam A. Jo , P.E.
Spokane County Engineer
encls: Plans (1 set)
cc: project file
Pat Harper/Scott Englehard
Dave Berto
Permit Technician - Sylvia Lightfoot
reviewer
7
. ~
' INLAND PACIFIC ENGINEERING, INC.
i
~
~
•
SpC~KANE. . . , t ENG1NEER'S OFFICE
-GONSTRUC`i'M PIANS- ~ •
PROJf~.'CT
~
DATE A`JVG: • .
~i'~YL..~.~y J. 2&54004V
ACCEPTANG. EXPli .&tp,~~ ~ . . . -
~ C0NSTRIJCTIOU DO(1UMEE`+lTATiAN ARlD CERTiFIED
REC:C3Rl7 DRRWIRGS ARE REQUiRED PRIOR TO RELEASE
OF BOND FOR O T~T~~1 JtEE!N. VlCES
L.~
, -
~~~KANE ~OUNTY , . , _
- O~~~`IC~~ ~aUBLI~; DO~,j~~'
~ DRA NAGEOTEC.
HNICAL U p
P'
for the . u Lu
0 ° ¢
°o,=
~ RIVERWALK 7TH ~ 4 ~ w
p z
- ADDITION PUD
~ <
1-
" 'I ~ ff
Ca ~ j
. 0 ~ o'~ O
U~ LUa" 0 co W~
LuU0 0
rU
a. < 2 O C) ~
JULY 1996 ~ ~ 4
~ C).
~
~pw~ ~
Prepared for: , o ~ ~v o ~
~ PACIFIC PROPERTIES .
~ 14410 Bel-Red Road
Bellevue, WA 98007 OFFICIAL pUBLIC DOCUMENT
~
SKZANE CflUNTY ENGINEER'S OFFlCt
~ ORG NA.
, Prepared By; PRO.tECT # F
Inland Pacific Engineering Company WMff TAL #
707 W. 7th Avenue, FE1'URN TO COUNTY ENGI114-i:ER
~ Suite 200
Spokane, WA 99204 ~
' (509)458-6840
~
~ .
L
~
~
~I
DRAINAGE REPORT
~ for the
Riverwalk 7th Addition PUD
Plat
' Spokane CountY, Washington ~
~
~ July 1996
Prepared for:
PACIFIC PROPERTIES
14410 Bel-Red Road
Bellevue, WA 98007
~
~ Prepared by:
~
_ Inland Pacific Engineering Company
~ 707 W. 7th Avenue
Suite 200
~J Spokane, WA 99204
_ (509)458-6840
~
. .
ti .r.:.:-:._.;-:::::.~r. .
~r...>:: . ~ . .......r:::~.:> :.vr.::~:_::._ _
~ . . . .
. . . ~ ~
. . . . .
Y~.,. . . . . .
. x. . . : . . . . .
j ' . - . •
. . . . . . .
ti.ry.;_: .
. . • . . . ~ ...::.ft~'- - k::>:--=•>'-•:':: " t::•':
. . . • .
o~:~ui:thYS~::et==~of`:~ :~ans::_aric~:;=:calcu~a~ons:;~confo.:rm~=#o.:~t~e .
. . .
. . r:~:r":
$ . ~
-...v..:..... vn:
.......yr . . . ~ .{i:•':~.}'
. ' ~ : r. -
' '
~ :•.ti ~ . ~ . ~ • •.i•:::~:ons: . : ~r,w ~ : : ~ . .:•}}:r:::~:: , -
~YCable: e~it~~~: okane~ ~iards::~for~~iQ~a~i~a~i::~ewer~`~onstruct~
_ :
~ :~P :
. . . . . .
: . .
. . . . . . . . .
. . .
.
.
: .
dfh'e s ~ ne ~ou~~ ~urdel~ies:::for_:~t~or~rnv~ater~lVl:~ne:~neiif: es~
. . .
: 'r: n~ . - .
p4~a:....
. . - ~
_
: . . . ~
, . . . . • • . . . : •.,,.w.v.. • ~ t o-:;. _ • , - - :r:~.:o-:•>:.:
~ .
-
!
,-..~~ti. J~.~..:.•. •..::•,V,• • x.J...:.' :M :Y:~L.. "
f.. {r . . •::::a':~' .'k •i•:i ~ a~ne-,~o.'_~u..~n!1 ~:.:~'~~.•.'.•::...•::.•.~.:f~
~ror~e~b:..:S...:~ . -ne.i
nee~: Ftii -:----~ove::es~::: :aris;~`~~:::~~-
:::a:
..:......:..::::.:PR~::.::.~:::...-.:.. .~'~:.%P.:- ; :--~P..:,: . . . . . .
: .
( .
. . .
.
~r:: . . . _
.
~ , . • . ~ , . • . .
. . . . . . .----•ttc : . ; ,
,for~ ns~r. , . - .
~ n .
>:.cal~u~a fi.Q
o . . .
~ .
. s . ~u .
_ . _
~ . . >;~r.; ,
. : .
' • . .:.'..Y:.:'.' • . l.1'!:: t..• ~
'17
~ This report has been prepared by the staff of Inland Pacific Engineering Company under the
direction of the undersigned professional engineer whose seal and signature appear hereon.
a CO
r--~ '
~ .
2 4
~1VAi. G
~ EXPIRES 9/24
Todd R. Whipple, P.E.
B .
I
Riverwalk 7th Addition PUD
^ Drainage Narrative
,
~ GENERAL .
~
The first phase of the Riverwalk 7thAddition PUD Plat is a 28.0 acre d-evelopment of 95 single -
` family residential lots located north and east of the intersection of Mission Avenue and Barker
J Road, within Spokane County, Washington. The site is currently vacant with field grass, alfalfa
~ and fallow fields as the predominant land cover and vegetation. Single fatnily residential
development lies directly to the north and west. A 1" to 400' scale vicinity and location map
have been included within the technical section of this document.
~
~ PURPOSE
^ The purpose of this report is to determine the extent of storm drainage facilities which will be
required to dispose of the increase in stormwater runoff created by the development of the
_ Riverwalk 7th Addition plat. The storm drainage facilities on this project will be designed to
~ dispose of runoff from either a ten year or fifly year design storm, depending upon basin size.
This development is within the Aquifer Sensitive Area of Spokane County and is subject to'208'
requirements. For this project, the 10-year curve from the Spokane, Medical Lake, Reardon,
Cheney and Rockford intensity curves was used, as well as the SCS iso-pluvial rainfall curves.
~ Per direction from Spokane County, the SCS curves have been further refined with the NOAA
iso-pluvial curves.
~ ~ -
~ - ANAL YSIS METHODOLOGY
~ Per the Spokane County Guidelines for Stormwater Management, the Rational Method, which is
recommended for basins less than ten acres in size, will be used to determine the peak discharges
and runoff volumes for all onsite basins. 'All off-site basins and all on-site basins larger than ten
acres will use the SCS Method to determine peak discharge and runoff volumes.
~ PROJECT DESCRIPTION
~ This phase of the Riverwalk 7th Addition plat comprises 95 lots of the approved 393 lots in the
approved prel'uninary plat and SEPA documents. The Riverwalk 7th Addition subdivision is
located in the NE 1/4 of the SW 1/4 of Section 8, T. 25 N., R. 45 E., W.M. within Spokane
County, Washington.
~
~ Inland Pacific Engineering Comparry D 1 Riverwalk 7th Addition Plat Drainage Repon
~
,
: .
~
" TOPOGRAPHY
The existing site sits along the south side of a low ridge sloping gently southwazd towards
Mission Avenue from Indiana Avenue. Within the plat the natural topography was used as much
~ as possible to route storm drainage. However, due to the flat slopes and the County's minimum
~ requirements for slope, many of the roadway profiles have been forced down to facilitate
drainage by localizing.low spots for pond placement....D-tte-to_the_flat_sl9pes encountered, no .
~ concentrated pre-existing flows were observed nor were there any signs that anything other than
~ sheet flow and grou.nd absorption have occurred on this site.
~ The general slopes within this plat vary from flat to neazly flat with the maxixnum existing slope
at 0.005/ft. Generally, the area within this platted portion of the overall preliminary plat would
be characterized as flat. For development purposes as stated the natural sloping was used for
design and is maintained as possible throughout the project.
SOILS
~ As can be seen from the accompanying soils map from the Spokane County Soils Survey as
J performed by the SCS, the site consists of one type of soils within the Class B type. This soil
type is described as follows.
GgA - Garrison gravelly loam, 0 to 5 percent slopes: Soils within this soil type are some what
excessively drained soils formed in gravelly glacial outwash material from a variety of igneous
~ rock. Surface runoff is slow, and the hazard of erosion is slight. Spokane County Guidelines for
Stormwater Management indicate this to be a Soil Group Type B and pre-approved for drywell
installation. _
~ . Hydrologic Soil Classification - B
~
.
~ DRAINAGE NARRATIVE
a
Offsite
Based upon the general geographic tendencies of this site, no appreciable amounts of offsite
flows are expected for this phase.
w Onsite
r As this plat is within the aquifer sensitive area of Spokane County all onsite drainage will be
collected and treated using the "208" runoff inethod as described in the Spokane County
~ Inland Paci,fic Engineering Comparcy D2 • Riverwalk 7th Addition Plat Drainage Report
~
1
~
~
Guidelines for Stormwater Management. To facilitate this analysis the Riverwalk 7th Addition
plat was divided into 27 permanent sub-basins ( A through Y3). Although there are 27 basins,
these basins have been combined where practical to utilize the same pond. Table 1 lists the
basins and pond combinations for easy reference.
~
~
~ -
~
~
~
d~J
(
/
~
~
J
2.--~
~
~
~
Inland Pacific Engineering Company D3 Riverwalk 7th Addition Plat Drainage Report
~
~ .
,
Table No. l- Pond and Basin Summary
.
.
. .
. . . .
. . . .
. .
: ~ ,r _ _
-~r„
.
ti
. .
- .
: '
~ ........r.... ~.~ii~. ~A►~ I::`_:.>_;:;:::~'.:.>;::,.- .
. . . . . . .
_~i ,iAI:ST1;1~'~~VIAR•
:•::~:f+d•2:;.>
,
, .
.
~ . ..,r_'::::::•..,.. --;7i~~ ~~iii': .
~ ~
:~:•::<:::;.::r: .::::rr:x
. -
c - . .
• w:: . .
. ,nv::: • : ~ . ......}v . , : :.~,'::t•:
. •:vil:~}:_?T}:::~:
: r:
.
~
. vf:w:::: :v ~ . • • " • • v . . ' C `}^F,r,{'i:~'~ • S-} .
-:::;;~v•
. . ' 'S.
• . .-:::h'v• - -
"...n - .
1~ r . . . . . . ' f • ~'ti•}••
.:.~i~:'. .
' . .
. . •f: . . - l•Y:J . .{1•::~•~:•:.
. ~.r.... -._...~l~~ }L}'J.
y •
.~~::::~~E'~et:~T .';'•.V~~f h ::'~'+~t~1~::::<:::.::.
rvions --t.e.:~
Im
-":•^'rr:~::~• .......!~.~f..•::::.: . .:.e-:: i..,~~:: ~v.~:.~r:::::::
,v::•• ' ~ . .
. . , . „ .:.v.4•.~::. .i;:...
. : . . ~ ~ .........._...:v•:v.: •
..tikN.
: •.~.v~.""' - • ~f•.'.',`'' -
v::: • ........""':v.: :4}" . . .
. ~ w::. . ; ' : 1I'~:~v:':•.i}:t
. . .i = : .
....,v. . '•:::<~?v:'?:•:_ . i~A
. . . - k:C•}TS:" . " .~,t~ : w::..
. . . . . ' ' ::•:•Y.:i$•} '
. ~::J~~~'C~
~1'
: - •x: • • ~ ~-~-~1~1fif1.: s : :•:r.:f::.CS, S.. .r~.. . . . .
. .
t:•:._:-. .:.~.a.•: . ..I-3-.~7.::~::. :a,;::::: - - ~::..~:`i'=•:'`'::': ...l.:j:l-.::......
. . . ~ .
i
_ A A 45010. . . 13279 4879 ..0.33 1.03
~ B B 33675 11177 4877 0.37 0.77
` C C 42705 12650 4250 0.34 0.98
D D 36602 11305 5005 0.35 0.84
4 E E 19450 6290 2090 0.35 0.45
~ F F 73756 18043 6493 0.29 1.69
_
G G 15122 4190 2090 0.33 0.35
H H 58498 19548 6948 0.37 1.34
,
,
~ I I 73875 22100 9500 0.34 1.70
~ J J 76810 23165 10115 0.34 1.76
~ K K 30642 10202 4952 0.36 0.70
L L 64882 18717 6117 0.33 1.49
M M 36182 11632 5332 0.36 0.83
N N 44339 12869 5819 0.34 1.02
O O 61378 18819 6966 0.34 1.41
P P 31229 8679 2379 0.32 - 0.72
e
Q Q 26635 8364 3114 0.35 0.61
~ R1 RT 42059 10621 3271 0.30 0.97
o_. S S 26271 10051 4651 0.41 0.60
RT RT 109690 32636 14636 0.34 2.52
U U 179713 26113 10363 0.22 4.13
V V 80568 24609 9909 0.34 1.85
W W 15805 5979 2829 0.41 0.36
~ X X 5302 2659 1609 0.50 0.12
Y1 Y1 23985 14592 14592 0.58 0.55
F-1 Y2 Y2 31525 19236 19236 0.59 0.72
Y3 Y3 9069 5341 5341 0.56 0.21
-
~ Inland Pacific Engineering Company D4 . Riverwalk 7th Addition Plat Drainage Report
~
~
~ 11208" Calculations
Within each basin the streets are divided into sub-basins by curb drops, inlets, catch basins and
--V high and low roadway profiles where swales and no curbs are used. These facilities capture
upstream stormwater runoff from the impervious street surface and direct the runoff into grassy
'208' ponds. As shown on the '208' calculation worksheets included, the '208' storage volume
provided is adequate to perform'208' treatment for the runoff created by the first half inch of
~ rainfall. In some cases, the ponds are not quite large enough to provide '208' storage for all of the
upstream runoff. In such cases the excess is carried over to the next downstream ponds which
provide adequate capacity for the carry-over flows. However, for the Riverwalk 7th Addition
~ plat no carryover flows are anticipated, therefore, there are no intermediate ponds included..
Curb Drop, Inlets and Catch Basin Calculations
It is necessary to check the adequacy of the curb drops, inlets or catch basins provided to divert
the runoff from the gutter into the '208' ponds. Should these be required, the curb drop, inlet and
catch basin calculation sheets included show the required lengths of curb openings, or single curb
~ drops with lengths greater than 4.0', as well as the adequacy of the inlet grates or catch basin
grates. For curb drops greater than 4.0', either multiple curb drops are added or the curb drops
,
~ are lengthened as required.
DRAINAGE CALCULATIONS SUMMARY
- Calculations have been included for Drainage Basin considerations such as QTR 55 and pond
✓ routing calculations, Peak Flow, Time of Concentration, "208" sizing, drywell requirements,
inlet sizing, curb drops as well as culverts and pipe flow some of which aze summarized below
~ with the remaining- calculations included in the appendix.
~
~ Within the calculation section and where it has been determined necessary for clarity, several
~ sketches, as well as details from the plans have been incorporated to demonstrate assumptions
~ and conclusions.
r-,
~ Inland Pacific Engineering Company DS Riverwalk 7th Addition Plat Drainage Report
~
f
~
;
s
~
- J BASIN DESCRIPTIONS
Basins A through Y3
~
a~ Within this plat, and due to the general geographic features, several basic assumptions were
' j followed and can be used to describe each basin. First, due to the relative flatness of the plat and
project vicinity, minimum road grade is limited to 0.008'/ft; second, the swale section carried
~ over from Riverwalk 1 st, will only provide at a maximum 25-percent of the calculated capacity;
~ third, a large tract pond if practical will be used in the open space area; fourth, all other ponds
will be of the lot pond configuration; fifth, that where practical, drywells will be minimized by
combining basins and providing piping between ponds.
All of these steps have been used in various basins throughout the drainage design of this proj ect.
-
a~
r--,
~
~
~
I
~
,
o~
~ -
~ Inland Pacific Engineering Company D6 Riverwalk 7th Addition Plat Drainage Report
i
--f~ Table No. 2- Pond and 208 Basin Summary
. ..............yr. ..................n.tiv,h...."".... +Y.y~::w::.:....... v}....i.}:.~::::.::w.~..r::.:~.........r:~.~:::::;?:~:%ti+.
..r.N.-~ . . . .
.................v0...:•: w:r...............~....""'..............•.•.•.~..~......""..... ..................:.~::w•:::..•.:4:4:~.
:v: ::v:......:..
. .........ti... .
.....r...." ' . . . . . . r. .........r..r~ . .'r' :Y r
...t~ . . . . . • ' • • .~?~"-ti''`{:~?{~:{•'•:•::
~ .:::::::.:~.~:r•.
, . ....n.......v~.y ..............~....-•""r:.......... • fv.~: ..."""".::r..:: ......r..~.... ~:r :{ti
• . . . . . . } .
.
. . .
....titi.,-w,;.,.....L.:::.. ...~.~.tiw:::.:...• •:.}:r;•.;•r:::.::::. r'~.. r.. :w.:~:......
+ . .
r.. r . . : r.... • • ~ i
.y~ti~.."'"":.................::... ; . •y F' ;
. ................S:.ti.
{y v: ~ . ' ':y•: .;r.;•.
~♦Q,+~f} ~
~i ti :.i:v: ~ ' ~
....r.;;:.}}:w}}i}:$
:tL: •vw: . . :
~ •}iw:::{{{?{'i•'. r ~ ~$'r
v:
. . ~ ~~~'.P:~•:~:~~I~~:,~.•~~ . .t.
. .
r..... . r.':{;._~•, V ..f•7►/1~7►:7:'~: r
B
. f r: •:,::r::::....
• ~ .
ti : , a ,..w..►.~..ar-'-' -::r. . . :iwY+~wsau►»
' ....;r~r
. .
. h~ , . n•::::. ~ ~ .....ti~::::: x r:::•r: _.r;.;::. .r.::a:•:: • ~ :.>.;t~::: x%•: rs: r :•r:t;?:•.
:v: .......r................... ....r..r......... xlr...... ...w::i:i:::::.., y:::::::
.
•i~~i 1.•}ii:G ::.:.v i {
.......:v•. .
• . . .
. .
. . . • v.: :.......y:::::: ..........wr.~~ :v. • v
. . ..tiJ..... ....:1::....... ...:::~•~,t .......:.J:: Yl.l::•'. ..................}.:~::1.'1:.:•.. :'f.~:::'.'.~..:•l.'.~'~~~•.~..~'::.~.'.•~~f.}~l
. .
~ :::....~i • ~ . • •i. ~ . • :•.ti ~ .1.1pf J . Y--
.
~ . : : Y~•.•.'.:...':: i i • . . l . . ~ ~ . J:...:.:: :
. ~ ~•t~N.• . ~ l:.
~ ! . ~ ; • . :
......J ti......
. • ..h .
;
. . ' . x~: . ii~::::.:.. :.~M:•:...~..'•:::1
g .............~tHt~. :
: J~~ftiti••
. .
. • • ...~~~R•.
.ti • ':::.Y. • . y 1' :{•.ti•.•:•}• • .
.ti . . . . ~
..~.N~.r::: ~
~
)
k ......"'.....~k....... . • . . v?
........~..vr........ . ~ n......:: r: . . ....~{+'i':':::{::.~.}}}w::::;. -:4~•f
...r...... . :v •
. . . ~ . ~ . ~ ~ .ti x~::: ~ y; " . r.. ~ f!r!.•i::r: }
....r. ..r... .................r.q'
..r :r.~ r:~. ' r : _::::"r. r.... ~~:rr~ :~:vr:•. }~•::jti.'.::r:
, z
~ ~ C:w:'
w. . .
•.ti4~~w:::.~:.~:::.~ ...w
i~~ •~Y3:~~ + i~:@i~•::::::>:.~: ;
. r. ~~~•:t~l•. : :-~•X
~ ~ i ~ i . . . • . Y X.: '~~•::•}.•!f. . • \~/.l.:'. % • l:}•: •f r. JJJ.•NJ!!.•:.::::•
~{V::::: •:ti{•f.:' ...:::::.:Y: r
:::~•~s?'{ ::::::::::::::rrrr~ . ~~..x~. : -::::::rr,,..~............ . . ;
a '
~ A A 203 406 426 1B
B B 203 406 426 ~ 1 B~
`j C C 177 354 375 1B -
D D 209 418 426 1B
~ E E 87 174 180 1B
F F 271 542 798 1B
G G 87 174 180 1B
H H 290 580 691 1B
I I 396 792 1097 1B
J 1 421 844 990 1B
K K 206 412 419 1B
L L 255 510 676 1B
~i
1 M M 222 444 470 1B
N N 242 486 500 1B
O O 290 580 600 1B
~
P P 99 198 210 1B
~
~ Q Q _ 130 260 275 1B
Rl RT - - - -
~
S S 194 388 400 1B
RT RT 610 1240 1800 1 B
U U 432 864 1132 2B
j
V V 413 826 1088 1B
~ W W 118 236 256 lA
X X 67 134 143
.
~ Yl Y1 608 1216 2666 / n/a
Y2 Y2 802 1604 3460 n/a
c- Y3 Y3 223 446 713 n/a
~
-Z~M~
TYPe A is a SPokane Standard Drywell - Single DePth, Capacih' 0.3 cfs
- Type Bis a Spokane Standard Drywell - Double Depth, Capacity 1.0 cfs
~
~ Inland Paci,fic Engineering Company D7 Rivenvalk 7th Addition Plai Drainage Repon
Table No. 3- Curb Drop/Catch Basin Summary
~ . ,r -
x .:~:::::.:..:.::.::::::::.:..::..:::<.::.:.:r
• • " : ~
...sa:b . . ...............r k..~ . ; • ~'tt':::::t;:;:i:+... ..,ti•;t.r....~
. . . ......................r..... n. .
ti . r . . .ti......... . . . . •;}y
F'~ 4.r.ti....... . . . . . . . v .+}Y.b':•.':::.;v.~:.:::.~:'w: •?}i+
, ..."'......vn• ;v: :::5:5::..
r.. r:::::: • . • . ....................v. r... . 3f ~ . : ~2 - - `+S.o-.~.~:'.'-:::
.
: s'•:: -
..::a:••.~:::.~:: . ti....• ~::vr:•,;--•..;::
. .a r.:.::. ~ . . • • : • : ~ • ;.fid'; , r: i ~ .
r: k• . .
:t?~.,-•:::. _ ,
~ • :
~o f~
: ....r::::::•
't::: J. ~•f. •::.ti•:::: ' tf'ti • • J. • . . . . . h f •.1l.:.: ..L . . . _ . .
. fT.... ....~.~h..v.... ....~~n....~~.... ..r::: ~r
iiHMMMiF ~MMF~M~Wii . ......t~a►N~Mii:..:Mi• : • ~k.. . ';1NYtii
. . ~~...........~W~MMH yY
....f. . .................:....:::f.~'.~nV::N:I 1}:. ......y..r.v:,-;: • • .Y.~
~ ti , ..••..V....... f.~
. . . . . ~.1 .......J~ . . •.~.........:~i`:i~.~....~• • • •.•.V.:........:.:~.~~~~~.~...~:••..
. f. •.r................J...... •J l..
?r:.:;:({ wr?i' :•}i:: }}:v:~:
.................:::4:::::•~i:ti4.4':~:}$..
, . .v.~.... v: . ......................n••:.~::: :v•.~::::::: .
,w_ .....h_ ...r.. .
. . . •v..... :::v. n.~::r
.......~...........r ..y~. ...x......"'"' ; ...............~x.:~::': ~•}}}}}r:::. r.t........... ~ v::::
r . . . r..... ......r................. ......v. ~ .y......:..;
..n . r........ .
? 4}:
. . n . n . x :::::v .'.•r{r:: y'•: w. ~ •}i~: t .w:..:. •
. .:h...:..•.~:.~::::: ..:::::.~:::w::::.ti...... ~
:::.A r :4 ...................v. .v:::.__:.::. . ..........:r::::: :v.: • .
ti . . .f r . .
....n. . _ . ~.n . r. . • ......w:.~:i.~;. ~::.vC~ti ..,7:tiwi>J:Ji9}:
. . . .
. S~~lC1E..~ . . .~t~.;.:::::..:: .
..r.~:::..... .
~ ..:......r.: . . ......~.::::......f
~ ................r......... . . . . ....~0 1 "
.......................v....... .....::r............
. r{... ~(x'ir.r..._..... r... x::r~i:'•.:..."::'; ' .:.}}}}}}v::..r.titi:v: .
.~.1'{.•:::.~.::f.~.':.1.1'.J•J:.•.:~::•'.':•.
. :f::::::t- ' :::.1:. :
J
..................1JlLy•y••. :•::•:t.~.~.......... .::lltf.::.~ • .lJ~::'......... ......................:::•:X:f•':.•'~.......... fJ:•:•
~ti ~ ........L............ l...... •1. lfJff: J . . :•!.•l` :r1Y~•X:: ~ ~ • ~ / 'a J ~ ~ •l.•.':'::•:•::•::.•. ::::{•:Y~f.•:::: f +
- k......... .}4
y~4 . v.~: • w:.~:::::....' ~?}'.{:}::}i: .
.
.
i: i:::..~' . ~5:.•..• . f.V • J 'A•.YN:':: ~ ~ ~•J}}:~~ . ~ k . ' • ..1 k f.Y~.]~~h}::::':::
~ l....... . •
. r......... . : :~i}'f:k' : . ::-.~i:{ti.} . :w:... , _ . :r::r.}:v:}:;$'i:::'
. . : ~ ~~Y~t
. •
.........r.~...... ~
. .'LV.........., ..................r~w.....n.. w:...............:.~: . ;.}.•x'Sv•,•,•,•::::.:........... ~}:?Y}~?{?::....~..~.i}:{
~ ..............y::: vr'•:: ......ljrr:. ~w::::::: .........r:::::: :•;x}:: :v•,, kv...."'.....h........ ....n.....
~ . '
RT _ RT Sump
~ Q Q Continuous -
~
W W Continuous -
U U Sump -
V V Sump -
~
~ Y 1 Y 1 Sump (All) ~ -
Y2 Y2 Sump(All) -
Y3 Y3 Sump(All) -
.
} Per Spokane County Guidelines curb drops in a sump condition have a capacity of 4.0 cfs
Per WSDOT Hydraulics Manual, Grate Inlet, has a sump capacity of 13.0 cfs
NOTE:
_ Only curb drop and grate calculations were performed for those
cases "On Grade", curb drops and catch basins in sump condition
are assumed to handle 4.0 cfs.
~ .
~
~
~
Inland Pacific Engineering Comparry Dg Riverwalk 7th Addition Plat Drainage Report
COUNTY, WASHINGTON - SHEET NUMBER 67
R. 44 E. I R. 45 E.
. :4~ti; 1. r„~=,~ ~ ,-r~...~ - (Joins sheet 58) (
y+~~~ ~ • ~y e ^ne .~.J~ ~ ~ iq•
, ,~C~ - , z,, O ~
ar' • - ~~',v~ - ~ `j'_ ~~~yyy~~'yi
V
_ CA. N ~f ~ • • ~ ' f~ ` n B
.
~ ■ • • • M, : . ~ ~
H h G A
` + • ~s,,.~ ~~1.~ _ ~ •
.
- ~ ~ e~'~'' r ' ~ ~ Y. • , ~ •
- ' + ' . . : _
:
i~' • ' •
-
. s~
~ / ' . Yy
i
, ,6 ' .
` \ ~ t V~~y.'i:~ j~, ' ~ ~ ~ s 9.~~ ♦ .
' • `(9y,~~~N , „ 1 _ - v `
.i
I `!i. •a ~ ~ I'
b ~ c~B
.
,
~=y~~ ` :~.c_~.~' • ~
• ~ K ~ . .
~ a ~ ~ • .~i"~r:.~~: •
(ti ~2,~, • ~ s
~ ~ ~ ~ " ' , % ~ ~ e
. ~
i -
1 ~ 7~ ' ~ •
,~4,~ ~ ~ '3 t _ i•v1~~ 1 C ~
► -T~'' Si's~ • ~ ' ~~r ~ ~ ~ ~ ~
gA.~~'
r - _ •'t• y~` ` y
/ • C
.~q
• n!~i ~ Q
~ r !
%r
` , ~ I ~ ~ ~ 4~ ~ ~ ~
.
- < -
~
- - - -
- .
y
~ ~ -
- L - -
L
~
t ~x P ~ gA
~
.
~i ~ 1f q,' - . . :~~.~'~~:•W:• 1~,
(Jans sheef 76)
~ 1 Mile
~ ~ Goi.. ~ - '~n nnn
ApP
1
~
~
~
~
~ - .
~ ~ .
~
< <
~ I
~
rain.a8e Rep°rt
River►+~utk 7th Addition Ptat B
~
j Inland Pacific EnBineerin8 C°MPany
n
~
(
~
~
~I
I
RUNOFF COEFFICIENTS.
-
AND
~ PONDBASIN SUM S
.
~
~
~
f~
.J
~
{
>
i
.
{
,J
i
~
~
1
c~
~ •
Inland Paci,fic Engineering Comparry Riverwalk 7th Addition Pla1 Drainage Report
~
~i
~
Weighted Runoff Coefficient Calculation
Project: Riverwalk 7th Addition
Basin: A IPE Job 96070
Total Area (acres): 1.03 Designer. B. Howard
'Imp. Area (acres): 0.30 Date: 5118/96
Grass Area (acres): 0.73 - - - - ~ ~ Imp. Area "C": 0.90 .
~ Grass Area "C": 0.10 -
;
(Imp. Area)(Imp. "C")= 0.2700
~ (Grass Area)(Grass C")_ - 0.0730
1.0300 0.3430
I~
s ; Weighted "C"= 0.3430 0.33
1.0300
,
i
~
.
-J
f
~ i .
3 I
.
~
' .
i
Weighted Runoff Coefficient Calculation
Project: Riverwalk 7th Addition
. Basin: B IPE Job
Total Area (acres): 0.77 Designer:
--s Imp. Area (acres): 0.26 Date:
Grass Area (acres): 0.51
Imp. Area "C": 0.90
Grass Area "C": 0.10
,
~
(imp. Area)(Imp. "C")= 0.2340
; (Grass Area)(Grass "C")= 0.0510
0.7700 0.2850
o j Weighted "C"= 0.2850
0.37
,
0.7700
~
1
~r
1
, ' .
- il
. `
I
~
~
~
{
.
Weighted Runoff Coefficient Calculation
i
Project: Riverwalk 7th. Addition
Basin: C IPE Job 96070
1 Total Area (acres): 0.98 Designer: B. Howard
Imp. Area (acres): 0.29 Date: 5l18/96
~ Grass Area (acres): - 0.69 - - f i Imp. Area "C": 0.90
' Grass Area "C": 0.10 .
- , (Imp. Area)(Imp. "C")= 0.2610
(Grass Area)(Grass "C")= 0.0690 ~ 0.9800 0.3300 -
(
~
~ Weighted "C"= 0.3300
0.34
0.9800
I
~i
-
~
I
~ .
~
4
-
~I
~
1
'
i
hted Runoff Coefficient Calculation
Weig
~ Project: Riverwalk 7th Addition
Basin: D IPE Job 96070
i~ Total Area (acres): 0.84 Designer. B. Howard
- Imp. Area (acres): 0.26 Date: 5/18196
Grass Area (acres): - 0.58 - - - - - ~ Imp: Area "C": 0.90
Grass Area "C": 0.10 -
IE •
(Imp. Area)(Imp. "C")= 0.2340
~f (Grass Area)(Grass "C")= 0.0580
~ 0.8400 0.2920
}
,
- Weighted "C"= 0.2920
0.35
0.8400
~i
p-.
~~I . .
J
~i
l .
~ .
LJ
_ J
IL
I
~
Weighted Runoff Coefficient Calculation
~ -
Project: Riverwalk 7th Addition
Basin: E IPE Job 96070
, Total Area (acres): 0.45 Designer: B. Howard
-Imp. Area (acres): 0.14 Date: 5/18/96
Grass Area (acres): -0.31 - - - - -
Imp. Area "C": 0.90
Grass Area "C": 0.10
I ~
~i
r~ (Imp. Area)(Imp. "C"), _ 0.1260
(Grass Area)(Grass C~~)- 0.0310
~ 0.4500 0.1570
Weighted "C"= 0.1570
0.35
0.4500
,i
~
.
.
~
.
3 .
t
~
~
Weighted Runoff Coefficient Caiculation
,
- Project: Riverwalk 7th Addition
Basin: F IPE Job 96070
~ Total Area (acres): 1.69 Designer: B. Howard
j~
Imp. Area (acres): 0.41 Date: - 5118/96
r-~ Grass Area (acres): -1:28 -
' Imp. Area "C": 0.94
-J Grass Area "C": 0.10
~ (Imp. Area)(Imp. "C")= 0.3690
`(Grass Area)(Grass C 0.1280
1.6900 0.4970
l ! Weighted "C"= 0.4970
0.29
1.6900
r • ~
~
1 .
I
r 1 .
1
i '
~
I j
,
~ ~ .
, .
~
i
Weighted Runoff Coefficient Calculation
Projec#: Riverwaik 7th Addition
Basin: G IPE Job 96070 -
Total Area (acres): 0.35 Designer: B. Howard
~
~--Imp. Area (acres): 0.10 Date: 5118/96
Grass Area (acres): -
Imp. Area "C": 0.90
~ Grass Area "C": 0.10 -
~
~.-(Imp. Area)(Imp. "C")= 0.0900
(Grass Area)(Grass "C")= . 0.0250
0.3500 0.1150
Weighted ':C"= 0.1150
0.33
0.3500
~ ~ _J
n,
I ~ .
r~ .
I
I I .
--I .
l_-
e
,
.
Weighted Runoff Coefficient Caiculation
Project: Riverwalk 7th Addition
Basin: H IPE Job 96070 .
Total Area (acres): 1.34 Designer. B. Howard
f Imp. Area (acres): 0.45 Date: 5/18/96
Grass Area-(acres): 0.89- - , - - - - - - -
~ Imp. Area "C": 0.90
( Grass Area "C": 0.10 -
(7
~
1 ~ (Imp. Area)(Imp. "C")= _ 0.4050
(Grass Area)(Grass C 0.0890
J
~ 1.3400 0.4940
~
i
Weighted "C"= 0.4940
1 'I 0.37
1.3400
.
~ .
~
Li
,
, .
.
~
_a .
~
1
Weighted Runoff Coefficient Caiculation
Project: Riverwaik 7th Addition
6asin: I IPE Job 96070
~ Total Area (acires): 1.7 Designer: B. Howard
~ Imp. Area (acres): 0.51 Date: 5/18/98 _
Grass Area (acres): 1.19 ~ Imp. Area "C": . 0.90
Grass Area C~~. 0.10
(Imp. Area)(Imp. "C")~ 0.4590
(Grass Area)(Grass C - 0.1190
1.7000 0.5780
r,
Weighted "C"= 0.5780
0.34
1.7000
.
k'
Z~
,
•
~ .
~
,
, .
, •
~ ~_i
1 ~
Weighted Runoff Coefficient Calculation
' ~Project: Riverwaik 7th Addition
Basin: J IPE Job 96070
Totai Area (acres): 1.76 Designer: B. Howard
,
. Imp. Area (acres): 0.53 Date: 5/18/96
. , Grass Area (acres): - - - - 1:23 ; tmp. Area "C": 0.90 Grass Area "C": 0.10 ,
~
;
, (Imp. Area)(Imp. "C")= 0.4770 .
(Grass Area)(Grass "C")= 0.1230
' , 1.7600 0.6000
Weighted "C"= 0.6000
0.34
1.7600
I S. -
l ~ I I
1` -
F
,
.
~
!i .
, .
'
1 ` .
,
-
i ' •
~
1
J - •
r--, '
i
1
,
Weighted Runoff Coefficient Calculation
i-~
Project: Riverwalk 7th Addition
Basin: K IPE Job 96070
Total Area (acres): 0.7 Designer: B. Howard
Imp. Area (acres): 0.23 Date: 5/28/96
, Grass Area (acres): - 0:4-7-
~ ; Imp. Area "C": 0.90
Grass Area "C": 0.10
.
(Imp. Area)(Imp. "C")= 0.2070
(Grass Area)(Grass "C")= 0.0470
0.7000 0.2540
; Weighted "C"= 0.2540
,
0.36
0.7000 .
~i
~
__--j - ~
~
~
f~
; -
; -
.
~i
~
.
i .
Weighted Runoff Coefficient Calculation
s---Project: Riverwalk 7th Addition
Basin: L ' IPE Job 96070
Total Area (acres): 1.49 Designer: B. Howar
Imp. Area (acres): 0.43 Date: 5/28196
~ Grass Area (acres): 1:06 . . . .
j ~ Imp. Area "C": 0.90
- ~ Grass Area "C": 0.10
~
,
(Imp. Area)(Imp: "C")= 0.3870
(Grass Area)(Grass "C")= 0.1060
1.4900 0.4930
~
~ Weighted "C"= 0.4930
0.33
1.4900
~J
1
7
~ .
i ,
i
I
,
,I .
_J
r;
.
i
Weighted Runoff Coefficient Calculation
f~
Project: Riverwaik 7th Addition
Basin: M IPE Job 96070
Total Area (acres): 0.83 Designer: B. Howard
Imp. Area (acres): 0.27 Date: 5/18/96
Grass Area (acres): - 0:56 - - - ~ ~ Imp. Area "C": 0.90 .
- Grass Area "C": 0.10
~
(Imp. Area)(Imp. "C")= 0.2430
(Grass Area)(Grass "C")= 0.0560
s^ , 0.8300 0.2990
I,
Weighted "C"= 0.2990
0.36
0.8300
~
s
~
~
~ ~ .
,
.
~
f
~
i
~
Weighted.Runoff Coefficient Calculation
1
Project: Riverwalk 7th Addition.
Basin: N IPE Job 96070
Total Area (acres): 1.02 Designer: B. Howard
~ I imp. Area (acres): 0.30 Date: 5/18/96
Grass Area (acres): - 0.72
~ Imp. Area "C": 0.90 .
- Grass Area "C": 0.10
~ .
,
(imp. Area)(Imp. "C")= 0.2700
(Grass Area)(Grass "C")= 0.0720
I s 1.0200 0.3420
Weighted "C"= 0.3420 .
0.34
1.0200
~
!s
1
~ .
J
I
(
( 4
I
I
L_ .
S • 1 I
I '
I
~ I
i ,
.
I
~
1
Weighted Runoff Coefficient Calculation
'Project: Riverwalk 7th Addition
6asin: O IPE Job 96070
E~ Total Area (acres): 1.41 Designer: B. Howard
' Imp. Area (acres): 0.43 _ Date: 5/18/96
~ 14 'Grass Area (acres): 0.98 ' Imp. Area "C": 0.90
Grass Area "C": 0.10
i ~
(Imp. Area)(Imp. "C")~ 0.3870
(Grass Area)(Grass C")_ - 0.0980
1.4100 0.4850
i
„
Weighted "C"= 0.4850 0.34
. 1.4100
j--,
s
~
S
,
s
,
~ . .
4-
y~
- -
r--, .
~I
,
f__(
~
; .
Weighted Runoff Coefficient Calculation
,
Pro1'ect: Riverwalk 7th Addition
Basin: P IPE Job 96070
Total Area (acres): 0.72 Designer: B. Howard
Imp. Area (acres): 0.20 Date: 5/18/96
, Grass Area (acres): 0.52- - - - -
~ s Imp. Area "C": 0.90
Grass Area "C0.10
S;
(Imp. Area)(Imp. "C")= 0.1800
. (Grass Area)(Grass "C")= 0.0520
~--I 0.7200 0.2320
{ Weighted "C"= 0.2320 0.32
0.7200
I~
,
l
t_
~
-
,7 .
L;
i.
I
_ , Weighted Runoff Coefficient Calculation
Project: Rivenivalk 7th Addition
. Basin: Q IPE Job 96070
Total Area (acres): 0.61 Designer: B. Howard
- Imp. Area (acres): 0.19 Date: 5/18196
Grass Area (acres): ' 0.42 - Imp. Area "C": 0.90. _
J Grass Area "C": 0.10
(Imp. Area)(Imp. "C")~ 0.1710
(Grass Area)(Grass C")_ - 0.0420
^ ~0.6100 0.2130
Weighted "C"= 0.2130
0.35
r ; 0.6100 I~
~
~ .J
r~
4 . .
~
~7
.
~
,
~ -
~
~
J
Weighted Runoff Coefficient Calculation _
i'
Project: Riverwaik 7th Addition
Basin: R IPE. Job 96070
f ~ Total Area (acres): 1.71 Designer: B. Howard
- - Imp. Area (acres): 0.48 Date: 5/18/96 Grass Area (acres): 1.23 -
i; Imp. Area C". _ 0.90
Grass Area "C": 0.10
~
~ (Imp. Area)(Imp. "C")= 0.4320
(Grass Area)(Grass "C")= 0.1230.
r ~ 1.7100 0.5550
;
Weighted "C"= 0.5550 .
0.32
1.7100 .
r-
. ,
,i
-
r-;
„
~ .
Ir' i
,y .
.
;
! f
Weighted Runoff Coefficient Calculation
~ ---Pro1'ect: Riverwalk 7th Addition Basin: R1 IPE Job 96070
Total Area (acres): 0.97 Designer: B. Howard
~i
Imp. Area (acres): 0.24 Date: 5/29/96
,--Grass Area (acres): 0.73 - - -
l ~ Imp. Area "C": 0.90 Grass Area "C": 0.10
I
`
I •
(imp. Area)(Imp. "C")= 0.2160 ! ! (Grass Area)(Grass "C")= 0.0730
,
0.9700 0.2890
Weighted "C"= 0.2890 ~ - 0.30
, -
0.9700
iL
~ -
;
s
~
-
_
i :
I ,I
'
Weighted Runoff Coefficient Calculation,
~ Project: Riverwalk 7th Addition
Basin: RT IPE Job 96070
' Total Area (acres): 2.52 Designer. B. Howard
~
- Imp. Area (acres): 0.75 Date: 5/29/96
Grass Area (acres): 1.77 - - m
Imp. Area "C": 0.90
Grass Area "C": 0.10
~
~ (Imp. Area)(Imp. "C")= - 0.6750
t JI (Grass Area)(Grass "C")= 0.1770
; 2.5200 0.8520
I
~Weighted "C"= 0.8520
I~
0.34
2.5200
~
l
~
~
~J.
~ -
~
n
, J.
.
, .
.
I ~
~
l J
~
1
I
~ .
Weighted Runoff Coefficient Calculation
-
~
' Project: Riverwalk 7th Addition
~ Basin: S IPE Job 96070
Total Area (acres): 0.6 Designer: B. Howard
J imp. Area (acres): 0.23 Date: 5/18196
Grass Area (acres): 0.37 ~ Imp. i4rea "C": 0.90 _
~ Grass Area "C": 0.10
I -
(Imp. Area)(Imp. "C")~ 0.2070
(Grass Area)(Grass C)- 0.0370
0.6000 0.2440
~
.~1
Weighted "C"= 0.2440
0.41
r , 0.6000
~
jl
~
~
!
,
~
;
~
I ~
r- .
E;
~
_ Weighted Runoff Coefficient Calculation
- Project: Riverwalk 7th Addition
Basin: T IPE Job 96070
Total Area (acres): 0.81 Designer: B. Howard
~Imp. Area (acres): . 0.28 Date: 5/18/96
- Grass Area (acres): 0.53
Imp. Area 0.90 _
Grass Area "C": 0.10 .
~ (Imp. Area)(Imp. "C")= 0.2520
(Grass Area)(Grass "C")= 0.0530
0.8100 0.3050
Weighted "C"= 0.3050
0.38
~ 0.8100
~
~
~ .
J
~
E 7
I I .
~
I
~
r, Weighted Runoff Coefficient Calculation
~
Project: Riverwalk 7th Addition .
Basin: U IPE Job 96070
~
~ Total Area (acres): 4.13 Designer. B. Howard
Imp. Area (acres): 0.60 Date: 5/18/96
Grass Area (acres): 3.53 " ~ ~ - -
. Imp. Area "C": 0.90
l- Grass Area "C": 0.10
-_r
~i -(Imp. Area)(Imp. "C")= 0.5400 (Grass Area)(Grass "C")= 0.3530
~ 4.1300 0.8930
Weighted "C"= 0.8930
0.22
4.1300 ~
~
~
.
~I
~
~
_s
~
-
I
~
r~
i
Weighted Runoff Coefficient Calculation
`Y.
.
Project: Riverwalk 7th Addition
Basin: V IPE Job 96070
Total Area (acres): 1.85 Designer. B. Howard
- Imp. Area (acres): 0.56 Date: 5/18/96
- - Grass Area (acres): " 1.29 - - -
~ Imp. Area 0.90
i
---Grass Area "C": 0.10
`I
y ~ .
~ (Imp. Area)(Imp. "C")= 0.5040
~ (Grass Area)(Grass "C")= 0.1290
~ 1.8500 0.6330
Weighted "C"= 0.6330
0.34
1.8500
~
a
~ .
-
~
~
• .
1
r~ ~ G
' I
I I
~
~
I '
~ i
,
Weighted Runoff Coefficient Calculation
--Project: Riverwalk 7th Addition
Basin: W IPE Job 96070
~Total Area (acres): 0.36 Designer. B. Howard
Imp. Area (acres): 0.14 Date: 5/18/96
Grass Area (acres): - 0.22 - - - i Imp. Area "C": 0.90 - -
' Grass Area "C": 0.10 °
i
r ~-(Imp. Area)(Imp. "C")= 0.1260
(Grass Area)(Grass "C")= 0.0220
0.3600 0.1480
I
~s
' Weighted "C"= 0.1480
0.41
^ 0.3600
~
~ .
,
~
~ _
i .
(
c
j7 -
L;
4
~
~ -
1
Weighted Runoff Coefficient Calculation
~ ~ - Project: Riverwalk 7th Addition
~-Basin: X IPE Job 96070
r~ Total Area (acres): 0.12 Designer: B. Howard
- Imp. Area (acres): 0.06 Date: 5/18/96
Grass Area (acres): 0:06
Imp. Area "C": 0.90
f Grass Area "C": 0.10 -
(Imp. Area)(Imp. "C")= 0.0540
~ (Grass Area)(Grass "C")= 0.0060
~ 0.1200 0.0600
~ Weighted "C"= 0.4640
0.50
0.1200
. . .
~I
I
i
i i .
i~
i .
1 -
~
I I
( y
1
,
-I
_ ~ .
. ~
. ~ PIPING DIAGRAMS
BACKWATER CALCULATIONS
~ PIPE FLOW CALCULATIONS
,
~
;
I
~
.
~
, -
~
~ -
,
` J • •
l
I J
~ I
l
~
f S
~ ' .
Inland Pacific Engineering Company Riverwalk 7th Addition Plat Drainage Report
I
~
__t
i '
Pipe Flow Calculation Basin RT
1I
- FIOW 0.640 CfS OUt IE 2027.72
_ Diameter 1.00 ft In IE 2028.44
' Slope 0.0063 ft/ft
n 0.0240
; L 115.00 ft d/dia A R Q V
~ Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 1.63 2.19
i;
! Flowing Full 1.00 ft 1.00 0.7854 0.2500 1.53 1.95
r--,,
1 i Critical Depth 0.330 ft 0.33 0.2260 0.1848 0.64 2.83
Normal Depth 0.450 ft 0.45 0.3428 0.2331 0.64 1.87
~ HWc 0.517 ft
HWn 0.531 ft OUTLET CONTROL
HWp ft
,
,
l
a
i
„
i .
~
l
S~
.
i~
ii
,
,
~
.
-1 .
Circular Channel Analysis & Design
- Solved with Manning's Equation
,
Open Channel - Uniform flow
Worksheet Name :'~~V~l,~f
Comment: _ _
Solve For Actual Depth _
--j Given Input Data:
Diameter.......... 1.00 ft
- Slope 0.0063 ft/ft
Manning's n....... 0.024
i Discharge......... 0.64 cfs
~
,
Computed Results:
~ Depth 0.45 ft
~ Velocity.......... 1.86 fps
-J
Flow Area......... 0.34 sf
Critical Depth.... 0.33 ft
~ Critical Slope.... 0.0192 ft/ft
Percent Full...... 45.08 g
Full Capacity..... 1.53 cfs
QMAX @.94D........ 1.65 cfs
Froude Number..... 0.56 (f low is Subcritical)
~ .
~
~
,
Open Channel Flow Module, Version 3.41 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
l I
~
- 1
~
Pipe Flow Calculation Basin RT
I~
- Flow 1.400 cfs Out IE 2027.37
Diameter 1.00 ft In IE 2027.62
Slope 0.0063 ft/ft
' n 0.0240
L 40.00 ft d/dia A R Q V
i'
' Depth of flow,d 0.90 ft 0.90 0.7445 0.2980 1.63 2.19
~
~ Flowing Full 1.00 ft 1.00 _ 0.7854 0.2500 1.53 1.95
Critical Depth 0.500 ft 0.50 0.3927 0.2500 1.40 3.57
r~ Normal Depth 0.750 ft 0.75 4.6318 0.3017 1.40 2.22
HWc 0.796 ft
~
,
HWn 0.864 ft OUTLET CONTROL
~ HWp ft
I'
4 ~
f~
1
f
~
~I
~
J
,
S
~
( I
l I
Circular Channel Analysis & Design
~ Solved with Manning's Equation
i~
Open Channel - Uniform flow
I , Worksheet Name: }tVeP-u)A-L-< '~~^~pDtTl
Comment: .
i! Solve For Actual Depth
~-Given Input Data:
I
~ Diameter.......... 1.00 ft
t~ Slope 0.0063 ft/ft
Manning's n....... 0.024
~ Discharge......... 1.40 cfs
Computed Results:
Depth 0.75 ft
;
~ Velocity.......... 2.21 fps
l Flow Area......... 0.63 sf
Critical Depth.... 0.50 ft
~ Critical Slope.... 0.0209 ft/ft
Percent Full...... 75.15 %
Full Capacity..... 1.53 cfs
\ QMAX @.94D........ 1.65 cfs
Froude Number..... 0.46 (f low is Subcritical)
~
✓
_ -
) -
~
i
Open Channel Flow Module, Version 3.41 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
~I
r~
~
~ ~ .
I
Trapezoidal Channel Analysis & Design
J Open Channel - Uni f orm f low
Worksheet Name:
i Comment:
Solve For Discharge _
Given Input Data: -
Bottom Width..... 2.00 ft
Left Side Slope.. 3.00:1 (H:V)
I-j Right Side Slope. 3. 00 : 1 (H : V)
Manning's n...... 0.030
Channel Slope.... 0.0080 ft/ft
Depth............ 0.25 ft
Computed Results:
~
Discharge........ 1.01 cfs
~ Velocity......... 1.47 fps
~ Flow Area........ 0.69 sf
Flow Top Width... 3.50 ft
Wetted Perimeter. 3.58 ft
Critical Depth... 0.18 ft
Critical Slope... 0.0254 ft/ft
Froude Number.... 0.59 (flow is Subcritical)
I
_ . '
i
1 .
~i
i
J
~ Open Channel Flow Module, Version 3.41 (c) 1991
2 Haestad'Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
i
rT
~
-
~ Trapezoidal Channel Analysis & Design
~ Open Channel - Uniform flow
r-~
i .
Worksheet Name:
' Comment:
L
Solve For Discharge . . _ . . , - . . -
Given Input Data: _
Bottom Width 2.00 f t
Lef t Side Slope.. 3. 00 :1 (H : V)
Right Side Slope. 3.00:1 (H:V)
Manning's n...... 0.030
~ Channel Slope.... 0.0080 ft/ft
~ Depth............ 0.50 ft
~ Computed Results:
I
~ Discharge........ 3.77 cfs
Velocity......... 2.15 fps
Flow Area........ 1.75 sf
Flow Top Width... . 5.00 ft
Wetted Perimeter. 5.16 ft
~ Critical Depth... 0.39 ft
Critical Slope... 0.0207 ft/ft
~ Froude Number.... 0.64 (flow is Subcritical)
~
~ ~,n~ ~ t'~ l.vt-~frr~ i~-,-. a'Ccu.c ~ ~.c.~ ~ ~r~a.r~ ~ ~ taA ,
!~,S'- ~'~:~I.J~ ~~U ; ~ , ~~~-C:~'r.. ~~i? ~•C~ ~ J.%C ~ CC~.~ - ~ j ~ ~ ~ % . ~ ~
r
~ ~~e~~ SWt~'~~
i ~
'4 :2-
~~~►r ~r~f 1.: c. ~ _ ~ ~ t~~,,._. ~ -
e},
I ~..J
~ i 1 _ ~
~ I
i Open Channel Flow Module, Version 3.41 (c) 1991
Haestad'Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
l .
i~
,
r ~
Backwater Calculation Sheet - Riverwalk 7th Addn. Pipe Segment CB2 - Out CB '1 to CB 2
. .
1 Q 1.40 0.64
2 Length 40.00 115.00
3. Pipe S¢e 1.00 1.00 4 n 0.012 0.013
5 Outlet EI. 2027.37 2027.72
6 Inlet EI. 2027.62 2028.44 , .
Slope 0.0063 0.0063
7 Barrel Area 0.79 0.79
8 Barrel Vel. 1.78 0.81
9 Vel. Head 0.05 0.01 10 TW EI. 2028.12 2028.62
11 Frict.loss 0.05 0.04 '
12 Entr, HGL:EI. 2028.17 2028.66
13 Entr. Head loss 0.04 0.01 14 Exit Head Loss 0.05 0.01 15 Outlet Ctrl.{EI. 2028.27 2028.68
Inlet Ctrl. HW 0.999 0.634 16 Inlet Ctrl. EI. 2028.62 2029.07 17 Appr. Vel. Head 0.00 0.00
18 Bend Head Loss 0.00 0.00 . Junct. HL Coeff. 0.00 0.00
19 Junct. Head Loss 0.00 0.00 20 HW Elev. 2028.62 2029.07 Grate E1. 2029.80 2030.54
Freeboard 1.18 1.47
~ - r..II~~ ~k..l ~ Y~r' T. " "~Yn,•'~~J t'•' 1. .
L
_j
_J 1
7 {
~l
l
,
!
c
~
~ .
- TIME AND 208 CALCULATIONS
~
~
n
~
__j
~
~
3
P
,I .
S
) •
~
I
~
S
J
I ~
_ J
Inland Pacific Engineering Company Riverwalk 7th Addition Plat Drainage Report
~
J
BOWSTRINGMETHOD PROJECT: RiverwalkTthAddftlon
PEAK FLOW CALCULATION PROJECT: Riverwalk lth Addkion DETENTION BASIN DESIGN BASIN: A
. BASIN: A 10-Year Des(gn Stam DESIGNER: B. Howatd.
Tot Area 1.03 Acres DATE: 5J31186
Imp. Area 4879 SF C = 0.33
Time Incremert (min) 5
CASE 1 Time oi Conc. (min) 5.89 .
Outflow (cfs) 1 100 ft. Overland Flow Design Yeat Flaw 10
Area (acres) 1.03
Ct = 0.15 Impervious Area (sq ft) 4879
L= 100 ft. 'C' Factor 0.33
n = 0.40 208' Volume Provided ;
S= 0.020 Area' C 0.343
, •
Tc = 4.44 min., by Equation 3-2 oi Guidelines , Time Time Inc. Intens. Q Deyel. Vol.ln Vol.Out Storage
187 ft. swale flow (min) (sec) (iMuy. (cis) (cu rt) (cu rt) (cu rt)
Z1= 3.0 For Z2 5.89 353 2.92 1.00 475 353 122
Z2= 3 TypeB=1.0
n= 0.040 Rolled = 3.5 5 300 3.18 1.09 438 300 138
S = 0.017 10 600 2.24 0.77 553 600 -47
15 900 1.77 0.61 619 900 -281
d= 0.394 ft. 20 1200 1.45 0.50 657 1200 S43
25 1500 1.21 0.42 672 1500 -828
A R Q Tc Tc totai I Qc 30 1800 1.04 0.36 '685 • 1800 •1115 ,
35 2100 0.91 0.31 693 2100 •1407
0.47 0.19 1.00 1.46 5.89 2.92 1.00 40 2400 0.82 028 709 2400 •1691
45 2700 0.74 0.25. 716 2700 -1984 Qpeak ior Case 1= 1.00 cfs . 50 3000 0.68 0.23 7728 3000 2272
. 55 3300 0.64 0.22 751 3300 •2549
60 3600 0.61 0.21 778 3600 -2922 '
CASE 2 , 65 3900 0.60 021 827 3900 -3073
70 4200 0.58 0.20 859 420D -3341 Case 2 assumes a Time of Concentratian less than 5 minutes so that the s 75 4500 0.56 0.19 887 4500 -3613
peak flow =.90(3.18)(Imp. Area) = 0.32 cis 80 4800 0.53 0.18 894 4800 -3906
85 5100 0.52 0.18 931 5100 -4169
% 90 5400 0.50 0,17 947 5400 4453
So, the Peak flow for the Basin is the greater of the two flaws, 95 5700 0.49 0.17 978 5700 -4122
1.00 cfs 100 6000 0.48 0.16 1008 6000 4992
I
x 206' DRAINAGE POND CALCULATIONS :
Requited'208' Storage Volume i
= Impervlous Area x.S In I 12 intft ' • 203 cu ft
.
. 2W Storage Volume Provlded cu ft
: DRYWELI REQUIREMENTS -10 YEAR DESIGN STORM.
~r Ma)dmum Storage Requlred by BowsMng 138 cu ft
Number and Type oi Drywells Required 0 Single
1 Double ~ , .
.
.
BOWSTRING METHOD PROJEC7: RhretHrallt 7th Addltlon
PEAK FLOW CALCULATION PROJECT: Rtrervralk 7th Addidon DETENTION BASIN OESIGN BASIN: B. BASIN: B 1aYear DesEgn Storm . DESIGNER: B. Hward
Tot. Area 0.77 Acres DATE: 5131l96
Imp. Area 4877 SF
C = 0.37 , Time IncremeN (min) 5 CASE 1 Time.oi Caic. (m[n) 5.96
Outfbw (cfs)
100 ft. Overland Ftow Design Year Flow 10,
Area (acres) 0,77
Ct = 0.15 Impervfouus Area,(sq ft) 4877 ,
L= 100 R. 'C Factor 0.37
n = 0.40 208' Vdume Provlded '
S= 0.020 Area' C 0.285
Tc = 4.44 min., by Equation 3-2 of Guidelines ` T(me Time Inc. Inters. .Q Devel. VoLln Vd.Out Storage
187 ft. swale flow (min) (sec) pM!~ (cis) (cu R) (cu rt) (cu R)
W.._~ ac_ce eam..a.~ aaasrssnm ae~assaa ea=aeea~
Z1 a 3.0 For Z2 5.96 358 290 0.83 396 358 39
Z2= 3 TypeB=1.0 '
n= 0.000 Rolled = 3.5 ' S 300 3.18 0.91 364 300 64 % So 0.017 10 600 2.24 0.64 461 600 439
15 900 1.77 0.50 -515 900 -385 .
d= 0.367 ft, ' 20 1200 1.45 0.41 546 1200 -654
25 1500 1.21 0.34 559 1500 -941
A R Q Tc Tc total I Qc 30 1800 1.04 0.30 570 1800 -1230
35 2100 0.91 ~0.26 576 2100 4524
0.40 0.17 0.83 1.53 5.96 2.90 0.83 % 40 2400 0.82 023 589 2400 -1811
; 45 2700 0.74 0.21 595 2700 -2105 % Qpeak for Case 1= 0.83 cts 50 3000 0.68 0.19 605 3000 -2395
55 3300 0.64 0.18 624 3300 •2676
60 3600 0.81 0,17 641 3600 •2953
CASE 2 % 65 3900 0.60 0.11 688 3900 -3212
70 4200 0.58 0.17 714 4200 -3486
Case 2 assumes a Time of Concentratlon less than 5 minutes so that the 75 4500 0.56, -0.16 738 4500 -3782
peak fiow =.90(3.18)(Imp. Area) = 0.32 cfs 80 4800 0.53 0.15 743 4800 -4057
65 5100 0.52 0.15 774 5100 -4326
90 5400. 0.50 0.14 787 5400 -4613
So, the Peak ftaw for the Bas(n is the greater of the two flows, 95 5700 0.49 0.14 613 5700 -4887
0.83 cis 100 6000 0.48 0,14 837 6000 S183
' 208' DRAINAGE POND CALCULATIONS Requlred'208' Storage Vdume
= Impervlous Area x.5 ln I 12 INft ' 2M,cu ft
208' StorAge Volume ProMded cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM Maaximmum Storage Required by Bowstring. ~ 64 cu ft .
Number and Type of Drywells Required ' 0 Single
' 1 Qauble
. . . , ' , . .
_
BOWSTRING METHOD , PROJECT: RhrenKalk 7th Add'rdon
PEAK FLOW CALCULATION PROJECT: Ritirervvalk lth Addftion DETENTION BASIN DESIGN BASIN: C . .
BASIN: C 10-Year Design Storm DESIGNER: B. Howard,
Tot. Area 0.98 Acres DATE: 5131156
Imp. Area 4250 SF
C ~ 0.34
Time Incxement (min) 5 CASE 1 ~ Time of Conc. (mfn) 7.01
Outflow (cfs) 1 . .
140 ft. dverland Flow De,sign Year flaw 10
Area (acres) 0.98 '
Ct = 0.15 ? (mpervious Area (sq ft) 4250
L= 140 ft. 'C' Factor 0.34
n = 0.40 ~ 'ZW Volume Pravided
S= 0.020 ' Area' C 0.330 Tc = 5.43 min,, by EquatiOn 3-2 of Guidelines
Time Time Inc. Irtens. Q Devel. Vof,ln Vd.Out Storage
160 ft. swale eow : (min) (sec) (tnmr) (cts) (cu tt) (cu R) (cu ft)
,
Z1= 3.0 For 72 7.01 421 266 0.88 498 421 78
Z2= 3 TypeB=1.0
n= 0.030 Rolled = 3.5 5 300 3.18 1.05 422 300 122
S= 0.010 10 600 2.24 0.74 549 600 -51
' 15 900 1.77 0.58 609 900 -299
d= 0.417 ik 20 1200 1.45 0.48 643 1200 -567
. 25 1500 121 0.40 656 1500 444
A R Q Tc Tc total I Qc 30 1800 1.04 0.34 667 1800 -1133 .
=L=== =3=== = =-=_====a ` 35 2100 0.91 0.30 674 2100 -1426
0.52 0.20 0.88 1.58 7.01 2.68 0.86 40 2400 0.82 0.27 ,688 2400 -1712
45 2700 0.74 024 - 694 2700 -2006
Qpeak fot Case 1= 0.88 cis % 50 3000 0.68 0.22 705 3000 •2295
55 3300 0.64 021 727 3300 2573
60 3600 0.61 0.20 753 3600 -2847
CASE 2 ' 65 3904 0.60 020 801 3900 -3099
10 4200 0.58 0.19 831 4200 -3369
Case 2 assumes a Time oi Concentratian less than 5 minutes so Ihat the 75 4500 0.58 0.18 858 4500 -3642
peak flow =.90(3.18)(Imp. Area) = 0.28 cis 80 4800 ' 0.53 0.17 866 4800 -3W5
85 5100 0.52 0.17 904 5100 -4200
90 5400 0.50 0.17 915 5400 4485
So, the Peak tiow for the Basln is the greater oi the two flows, 95 5700 0.49 0.16 945 5700 -4155
0.88 cis 100 6000 0.48 0.16 973 6000 -5027
, 208' DRAINAGE PONO CALCULATIONS ,
Requlred'208' Storage Vdume
. = Impervlauus Area x.51n! 121nlft 177a, rt:
„ 208' Staage Volume Provided cu rt
. i
DRYWELL REQUIREMENTS -10 YEAR DESIGN.STORM ~
Ma)dmum Storage Requlred by Bowsring ~ 122 ai ft
Number and Type oi Dryweils Requlred 0 Single
1• Double
F
_ - ' - - - - - ~
1.~--BOWSTRING METHOD PROJECT: Rivemlk7lh Additfon
PEAK FLOW CALCULATION PROJECT: Rhrervalk 7th AddiUon DETENTION BASIN DESIGN BASIN: D' BASIN: D 10-Year Design Stam , DESIGNER: B. Howard,
Tot. Area 0.84 Acres DATE: 5131196 ,
Imp. Area 5005 SF . C = 0.35
Time Incremem (min) 5CASE 1 Time of Conc. (min) 7.41 Outflow (cfs) 1
140 ft, Overland Flow Design Year Flow 10 .
Anea (acres) 0.84
Ct = 0.15 ImpeMous Area (sq ft) ' 5006
' L_ 140 fL 'C Fador 0.35.
n = 0.40 208' Volume ProNided
s= 0.020 area' C 0292 , . ,
Tc = 5.43 min., by Equatfon 3-2 of Guidelines
Tlme Time Inc. Intens. Q Devel. Yol.ln Vol.Out Staage
215 R, Swale flow (min) (sec) (lrVho (cis) (cu R) (cu R) (cu ft)
Z1= 3.0 For Z2 7.41 445 261 0.76 455 445 10
Z2= 3 Type6=1.0
n= 0.030 Rdled = 3.5 5 300 3.18 0.93 373 300 73
S= 0.013 10 600 224 0.65 491 600 -109
15 900 1.77 0.52 543 900 -351
d= 0.375 ft. ' ZO 1200 1.45 0.42 572 1200 -628
, 25 1500 121 0.35 583 1500 -917
A R Q Tc Tc total I Qc 30 1800 1.04 0.30 593 1800 4207 .
====a___= a=_'_====_ ==n===ea_ az'====:_ c====a==s_c===a==a 35 2100 0.91 0.27 598 2100 '1502
0.42 0.18 0.76 1.99 7.41 2.61 0.76 40 2400 0.82 . 0.24 614 2400 -1789
45 2700 0.74 0.22 , 618 2700 •2084
Qpeak for Case 1= 0.76 cfs 50 3000 0•68 0.20 626 30DO '2374
55 3300 0.64 0,19 645 3300 ,-2655
60 3600 0,61 0,18 668 3800 2932
CASE 2 % 65 3900 0.60 0.18 710 3900 -3190 '
70 4200 0.58 0.17 737 4200 -3463
Case 2 assumes a Time oi ConcentraUon less than 5 minutes so that the ~t 75 4500 0.56 0.16 761 4500 -3739
peak flow =.90(3.18)(Imp. Area) = 0.33 cfs ~ 80' 4800 0.53 0.15 766 4600 4044
85 5100 0.52 0.15 787 5100 -4303
% 90 5400 0.50 0.15 810 5400 -4590
So, the Peak 8aw for the Basin fs the greater of the two flows, 95 5700 0.49 0.14 837 5700 -4863
0.76 cfs , 100 6000 0.48 0.14 862 6000 -5138
} , .
208" DRAINAGE POND CALCUlAT10NS ;
; Requfred'ZOS' Storage Vdume Impetvious Area x.51n 1121Nft ~ 209 cu ft
~ •
208' Stotage Volume Provfcled , cu ft
' ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~
Nkwdmum Storage Required by Bowstring , 73 cu ft
Number and Type oT Orywells Requlred ` 0 Single
1 Double
. . ' . . . ,T,h , , . .
,
BOWSTRING METHOD PROJECT: Riverwralklth Addltion PEAK FLOW CALCULATION PROJECT: Rivwwalk lth AddiUon DETENTION BASIN DESIGN BASIN; E,
BASIN: E 1QYear Design Storm DESIGNER: B. Howard
Tot. Area 0.45 Aaes DATE: 5131196
Imp. Area 2090 SF . C = 0.35
Tlme IncremeM (min) 5 .
CASE 1 Time oi Conc. (min) 7.87 Outtlow (cis) . 1 -
150 ft. Overland Flow DesfBn Year Flow .10
Area (acres) 0.45 Ct = 0.15 Imperv(ous area (sq rt) 2090
L= 150 ft. 'C Factat 0.35 n = 0.40 , 208' Vdume Provided S= 0.010 NCa ~ V 0.157 Tc = 6.97 min., by Equation 3-2 of Guidelirtes
Time Time Inc. Intens. Q Devel. Vd:ln Vol.Out Storage
15 ft. Swale flow (min) (sec) (IMirI (cfs) (w h) (cu n) (cu ft)
:EM saa_ =='z= = a==aesa a===s~~
Z1= 3.0 Fa Z2 7.87 472 253 0.40 252 472 •220
Z2= 3 TypeB=1A
<L=
n= 0.030 Rdled = 3.5 5 300 3.18 0.50 201 ' 300 .99
S= 0.010 10 600 224 0.35 267 600 333
15 900 1.77 028 295 900 -605
d= 0.310 ft. ' 20 1200 1.45 0.23 310 1200. -890
25 1500 121 0.19 315 1500 -1185
A R Q Tc Tc total I Qc 30 1800 1.04 0.18 320 1800 -1480 ,
35 2100 0.91 0.14 323 2100 -1777
0.29 0.15 0.40 0.90 7.87 2.53 0.40 40 2400 0.82 0.13 330 2400 -2070
45 2700 0.74 0.12. 332 7T00 -2368 Qpeak fot Case 1= 0.40 cis 50 3000 0.68 0.11 337 3000 -2663
55 3300 0,64 ~0.10 348 3300 -2952
60 3600 0.61 0.10 360 3600 -3240
CASE 2 65 3900 0.60 0.09 363 3900 -3517
70' 4200 0.58 0.09 39I 4200 -M
Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.09 410 4500 4090
peak flow =.90(3.18)(Imp. Area) = 0.14 cis 80 4800 0.53 0.08 413 4600 -4397
85 5100 0.52 0.08 429 5100 -4671
so 5400 0.50 0.08 .ast saoo 4m
So, the Peak flow for the Basin Is the greater of the two flows, 95 5700 0.49. 0,08 40 5700 .6249'
0.40 cfs 100 6000 0.48 0.08 464 6000 -5536
. t , -
~ 208' DRAINAGE POND CALCULATIONS ;
Requfred'208' Storage Volume Impervfous Area x.5 in ! 12 iNft ; 87' cu ft
% ` 206' Storage Volume Provided ' w ft
ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM ;
MaAmum Starage Required by Bowstring , -99 cu ft
Number and Type of DryweUs Required 0 Single
1 Double
I
..~--_J
BOWSTRING METHOD PROJECT: RlvBrwalk 7th AddltbnPEAK FLOW CALCULATION PROJECT: Rivetvvafk 7th Additlon DETENTION BASIN DESIGN- BASIN: 'F BASIN: F 1QYear Design Stam 'DESIGNER: B. Howard
Tot. Area 1.69 Acres DATE: 5131196 .
Imp. Area 6493 SF ' C ~ 0.29
Time Increment (min) 5 CASE 1 Tirrie of Cortc. (min) 9.85 .
~ OuHbw (cfs) I .
150 ft. Overland Flaw Deslgn-Ye,ar Fbw 10
Are,a (aaes) 1.69 Ct = 0.15 Impervious Area (sq ft) 6493
L= 150 ft. 'C' Fador 0.29
' n = 0.40 '208' Volume Provlded .
S= 0.010 Area•C 0.497
Tc = 6.97 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devd. Vd.ln Vd.Out Staage
285 ft. Swale flow (min) (sW) pnmr) (cis) (cu R) (cu rt) (CU ft)
raa==-~ =~~a= -~===a:en sae= eaaa~sa --:==~a s»~a~
Z1= 3.0 Far Z2 9.85 591 2.25 1.12 886 591 295
Z2= 3 TypeB=1,0 n= 0.030 Ro11ed = 3.5 5 300 3.18 1.58 635 300 335
S= 0.008 10 600 2.24 1.11 . 892 600 292
15 900 1.77 0.88 968 900 69
d= 0.478 R 20 1200 1.45 0.72 1010 1200 •190-
25 1500 121 0.60 1073 1500 -477
A R Q Tc Tc total I Qc 30 1800 1.04 0,52 1034 1800 '766 •
.,==_a z==-^-===- ====z=== a==-^-==__ a= 35 2100 0.91 0.45 1041 2100 -1059
0.68 0,23 1.12 2.88 9.85 ~~2.25 ~1.12 40 2400 0.82 0.41 1060 2400 -1340
, 45 2700 0.74 0.37. 1067 2700 -1633
%
Qpeak for Case 1= 1.12 cis 50 3000 0.68 0.34 1082 3004 -1918 '
55 3300 0.64 0.32 1114 3300 •2186
60 3600 0.61 0.30 1152 3600 -2448
CASE 2 ' 65 3900 0.60 0.30 1223 3900 -2617
70 4200 0.58 029 1260 4200 -2931
Case 2 assumes a Time of Cortcertration less than 5 minutes so that the 75 4500 0.56 028 1308 4500 -3192
peak (low =.90(3.18)(Imp. Area) = 0.43 cfs 80 4800 0.53 0.26 1311 4800 -3483
85 5100 0.52 0.26 1370 5100 -3730
90 5400 0.50 0.25 1392 5400 -4008
So, the Peak flaw tor the Basin Is ihe greater of the two flows, ' 95 5700 0.49 0.24 1437 5700 -4263
1.12 cfs ~100 6000 0.48 0.24 1479 6000 -4521
208' DRAINAGE PONO CALCULATIONS
% Required'246' StorageVdume
Impervious Area x.5 In I 12 INft 271 -cu ft
208' Storege Volume Provided cu tt
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM .
M1Ilwdmum Storage Required by Bawstrfng 335 au ft
Number and Type of Dryweps Requlred : 0 Single
' ' 1 Double
BOWSTRING METHOD , PROJECT: Rhrerwatk 7th Additlon
PEAK FLOW CALCULATION PROJECT: Rivermlklth Addiffon DETENTION BASIN DESIGN ' BASIN; G .
BASIN: G 10-Year Design Stam DESIGNER: B. Howard
Tot. Area 0.35 Acres DATE: 5131l96'
Imp. Area 2090 SF . '
C y 0.33 . .
Time Inctement (m!n) 5 .
CASE 1 Time of Conc, (min) 7.65
Outfiow (cfs) 1 -
140 ft. Overland Flow Des(gn Year Flaw 10.
Area (aaes) 0.35
Ct = 0.15 Imperv(aus Area (sq R) 2090L= 140 R. 'C' Factor 0.33
n = 0.40 '208' Volume Provided S= 0.010 Area' C 0.115 Tc = 6.68 min., by Equation 3-2 of Guidelines
: Time Time Inc. IMens. Q DeveL Vd.in Vd.Out Storage
75 ft. Swale flow ' (min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft) '
` ==e~ a cae- -s xa~aa . e eax~ar~
Z1= 3.0 Fa Z2 7.65 459 2.57 0.30 182 459 -277'
Z2= 3 Type6= 1.0
n= 0.030 Ra11ed = 3.5 5 300 3.18 0.37 147 300 -153
S~ 0.010 10 600 2.24 026 195 600 406
15 900 1.71 0.20 215 900 -W5
d= 0.280 ft. 20 1200 1.45 '0.17 2Z6 1200 -974
25 1500 121 0.14 230 1500 -1270
A R Q Tc Tc total I Qc 30 1800 1.04 .0.12 234 1800 -1566 .
= 35 2100 0.91 0.10 238 2100 -1864
0.24 0.13 0.30 0.97 7.65 2.57 0.30 40 2400 0.81 0.09 241 2400 -2159
45 2700 0.74 0.09. 243 2700 -2457
Qpeak for Case 1= 0.30 cfs ' 50 3000 0.68 0.08 247 3000 -2753
56 3300 0.64 0.07 254 3300 -3046
% 60 3600 0.61 0.07 263 3600 -M7
CASE 2 65 3900 0.60 0.07 280 3900 -3610
70 4200 0.58 0.07 291 4200 -3909
Case 2 assumes a Time oi ConceMratlon less than 5 minutes so that tt►e 75 4500 0.56 0.06 300 4500 4200
peak ftow =.90(3.18)(Imp. Area) = 0.14 cfs 80 4800 0.53 0.06 302 4800 -4498
85 5100 0,52 0.46 314 5100 -4786
90 5400 0.50 0.46 319 5400 15081
So, the Peak flow for the Basin IS the gmater oi the lwo flows, 95 5700 0.49 0.06 330 5700 431o
0.30 cfs , 100 6000 0.48 0.06 340 6000 -5660
208' DRAINAGE POND CALCULATIONS '
Requfred'Z08' Staage Volume z Impervious Area x.5 In 112 Inlft ; 87 cu ft
208' Storage Vdume Provided , cu ft
DRYWELLREQUIREMENTS-10YEAR'DESIGNSTORM '
Mwdmum Storage Required by Bowsktrrg 453 cu R
Number and Type of Orywelis Requlred ' 0 Sfngle ,
1 Double
; - • ,
BOWSTRING METHOD PROJECT: Rivemlk 7th Additlon
PEAK FLOW CALCUlATION PROJECT: Rhrerwaik7th Addrdan, DETENTION BASIN DESIGN BASIN: H'
BASIN: H 10-Year Design Storm DESIGNER: B. Howard
Tot. Area 1.34 Acres DATE: 5131196
Imp. Area 6948 SF C = 0.37 ' Time Inaement (min) 5
CASE 1 Tlme of Conc. (m(n) 9.19
Outtlow (cis) 1. 140 ft. Overiand Flow Design Year Flow 10
Area (acres) 1.34
Ct = 0.15 Impervlous Area (sq ft) 6948
L= 140 ft 'C Factor 0.37
n = 0.40 208' Volume Provirded
S= 0.010 Area' C 0.494 ,
Tc = 6.68 min., by Equatlon 3-2 of Guidefnes
Time, Time Inc. IMens. •Q Dewel Vol.ln Voi.Out Storage
250 ft. SHrale flow (m(n) (sec) pNhr) (cfs) (cw.ft). (cu ft) (cu ft)
Z1= 3.0 Fot Z2 9.19 551 2.34 1.16 856 551 304
' 72= 3 Type8= 1.0 , '
n= 0.030 Rolled = 3.5 5 300 3.18 1.57 632 300 332
S= 0.006 10 600 224 1.11 ' 871 600 271'
15 900 1.77 0.87 951 900 51
d= 0.483 R 20 1200 1.45 0.72 994 1200 -206
. 25 1500 121 0.60 1009 1500 -491
A R Q Tc Tc total I Qc 30 1800 1•04 0•51 1021 1800 '779 •
35 2100 0.91 0.45 1028 2100 -1072
0.70 0.23 1.16 2.51 9.19 2.34 1.16 40 2400 0.82 0.41 1048 2400 -1352
45 2700 0.74 0.37 . 1056 2700 -1644
Qpeak fa Case 1= 1.16 cis 50 3000 0.68 0.34 1071 3000 -1929
55 3300 0.64 0,32 1103 3300 •2197
60 3600 0.61 0.30 1141 3600 •2459
CASE 2 ` 65 3900 0.60 0.30 1212 3900 -2688
70 4200 0.58 0.29 1257 4200 -2943
Case 2 assumes a Tfine of Concentratlon less than 5 minutes so that the , 75 4500 0.56 0.28 1297 4500
peak flaw =.90(3.18)(imp. Area) = 0.46 cfs , 80 4800 0.53 0.26 1306 4800 -3494:
` 85 5100 0.5'w 2 0.26 13A5^8^ 5100 ~,7/~~42 '
M
1 W ~ O.W 0~ ~~I~/~I ~
So, the Peak fl~ow (or the Basin is the greater oi the two flows, 95 5700 0.49 0.24 1425 5100 -4275
1.16 cfs , 100 6000 0.48 0.24 1467 6000 •-4533
% % 208' DRAINAGE POND CALCULATIONS ~
Required'2W Storage Vdume '
, = Impervious Ara x.5 in ! 12 INft 290 cu ft
;
208' Storage Volume Provided : W ft
~ DRYWEII REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Staage Requlred by BoH►stiing 332 cu ft
: Number and Type of Drywells Requfred 0 Single
1 Double
BOWSTRING METHOD PROJEC7: Rfvenralk7th AddlUon
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addidon DETENTION BASIN DESlGN BASIN: I
BASIN; I 10-Year Design Stotm .DESIGNER: B. Howard,
Tot. Area 1.70 Acres DATE: 5131196
Imp. Area 9500 SF f '
C = 0.34
Tlme IncremeM (min) 51
CASE 1 > Tlme of Conc. (m(n) 6.85
Out(iow (cfs) 1 75 ft: Overiand Flaw Oeslgn Year Flow 10
Area (acres) 1.7
' Ct = 0.15 Impervious Area (sq R) 9500 '
L= 75 R. 'C' Fador 0.34'
n = 0.40 208' Volurne Provlded
S= 0.020 Area' C 0.578
Tc = 3.73 min., by Equatlon 3-2 of Guidellnes
Tfine Time Inc. Irderis. Q,Devel. Vd.ln Vol:Ovt Stornge
350 ft. Swale fiow (min) (sec) (Wlu) (cts) (w 1t) (cu ft) '(cu ft)
Z1= 3.0 Fot Z2 6.85 411 2.71 1.56 862 411 451
Z2 = 3 Type B =1.0 .
n = 0.030 Roiled = 3.5 5 300 3.18 1.84 739 300 439
S= 0.009 10 600 224 1.29 958 600 358
' 15 900 1.77 1.02 1064 900 164 '
d= 0.527 ft. 20 1240 1.45 0.84 1123 1200 77
25 1500 121 0.70 1147 1500 -353
A R Q Tc Tc total I Qc 30 1800 1.04 0.60 -1166 1800 -634 ,
a===~--_= 35 2100 0.91 0.53 1178 2100 922
^ 0.83 0.25 1.56 3.12 6.85 2.71 1.56 40 1400 0.82 0.47 1204 2400 -1196
45 2700 0.74 0.43. 1215 2700 -1485
Qpeak for Case 1= 1.56 cfs , 50 3000 0.68 0.39 1234 3000 -1766
55 3300 0.64 0.37 1272 3300 -2028
. ' 64 3600 0.61 0.35 1319 3600 -2281
CASE 2 % . 65 3900 0.60 0.35 1401 3900 -2499
% 70 4200 0.58 0.34 1455 4200 -2745
Case 2 assumes a Time ot Concentration less than 5 minutes so that the ~ 75 4500 0.56 0.32 1502 4500 -2998
peak flow =.90(3.18)(Imp. Area) = 0,62 cfs , 80 4800 0.53 0.31 1513 4800 -3287
% 85 5100 0.52 0.30 1575 5100 -3525
% 90 5400 0.50 0.29 1601 540D -3799
So, the Peak flow iar the Basin is the greater oi the two flows, 95 5700 0.49 028 1654 5700 4046
1.56 cfs 100 6000 0.48 0.28 1700 6000 -4297
208' DRAINAGE POND CALCULATIONS '
Required'Z08' Staage Volume
%Impervious Area x.5 ln 112 iNft 39Q cu ft
208' Storage Volume Provlded cu R
DRYWELL REQUIREMENTS -10YEAR DESIGN STORM
Mwdmum Storage Required by Btiwstring , 451 cu ft
%
Number and Type oi Drywells Required ' 0 Single
1 Double
e
BOWSTRING METHOD PROJECT: RNerv►ralk 7th Addiiti~on
PEAK FLOW CALCULATION PROJECT; Rivernalk lth Addftion DETENTION BASIN DESIGN BASIN: J
BASIN: J 1o-Year Design StoRn DESIGNER: B. Haward
Tot. Area 1.76 Acres DATE: 5131196
Imp. Area 10115 SF
C = 0.34
Time Increment (min) 5
CASE 1 ; Time oi Cona. (min) 6•38
Outflow (cfs) 1
75 ft. Overland Flow Desdgn Year Flonr 10
` Area (aaes) 1.76
Ct ~ 0.15 Impervious Area (sq R) 10115
L= 75 ft. 'C Facta 0.34' '
n = 0.40 208' Volume Froyided *
s= 0.020 aea ~ c a.soo
Tc = 3.73 min., by EquaUon 3-2 of GuideBnes Time Time Inc. IMens. Q Devel. Vd.ln Vd.Out Storege
302 ft. swale flow (mIn) (see) (Cfs) (CU ft) (CU ft) (CU ft)
naaa====~ es== a===ass~a rM~ c----^:as ==aas+---°
• Z1= 3.0 For Z2 , 6.38 383 2.80 1.66 861 383 479
Z2= 3 Type6=1.0 '
n= 0.030 Rolled = 3.5 5 300 3.18 1.91 767 300 467
S= 0.009 10 600 2,24 1.34 981 600 381
• 15 900 1.77 1.06 1094 900 194 '
d= 0.542 ft. 20 1200 1.45 0.87 1157 1200 43
25 1500 121 0.73 1183 1500 -317
A R Q Tc Tc total I Qc 30 1800 1.04 0.82 1204 1800
=-======II 35 2100 0.91 0.55 1218 2100 -082
0.88 o.~ 1.6e ~ 264 6.38 2.80 1.68 aa 2400 0.e2 0.49 1246 2400 -1155
as 2700 0.74 0.44. 1257 zraa a443
Qpeak for Case 1= 1.68 cis 50 3000 0.68 0.41 1277 3000 •1723
55 3300 0.64 0.38 1319 3300 -1983
60 3600 0.61 0.37 1365 3600 -27,35
CASE 2 65 3900 0.60 0.36 1451 3904 2449
70 4200 0.58 0.35 150~ 4~0 •2693
Case 2 assumes a Time of Conce~atlon less than 5 minutes so that the 75 4500 0.56 0.34 1566 4500 -2944
peak Bow =.90(3.18)(Imp. Area) = 0.66 cfs 80 4800 0.53 0.32 1566 4800 432
85 5100 0.52 0.31 1632 5100 -3468
90 5400 0.50 0.30 1650 5400 -3741 ,
So, the Peak flow for the Basin is the greater of the two flows, + 95 5700 0.49 0.29 1714 5700 -3986
1.68 cfs ~ 100 6000 0.48 029 1765 6000 -4235
5
4X ; " ~ 208' DRAINAGE POND CALCULATIONS
Required'208' Storage Volume ~ Impervlous Area x.5 In ! 121Nft , 421 cu ft
% . ' '
208' Storage Volume Provlded ' eu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~
MaAmum Staage Requ(red by Bowstring 479 cu ft
Number and Type of Drywelis Requlred ' 0 Single
1 Double
~ BOWSTRING METHOD . PROJECT: Rlverwalk 71h Additlon
PEAK FLOW CALCULATION PROJECT: Rtrerwalk 7th AddiUon DETENTION BASIN,DESIGN BASIN: K BASIN: K 10-Yar Design Stam DESIGNER: B. Howard
Tot. Area 0.70 Aaes DATE: 5131196
Imp. Area 4952 SF ' .
C = 0.36
Time Increnient (m(n) 5`
CASE 1 Time of Conc. (min) 8•56 . Outflow(cfs) 1 ,
130 ft, Overland Flow Design Year Flow 10
qrea (aaes) 0.7
Ct = 0.15 Imperviats Area (sq R) 4952
L= 130 ft. 'C Fector 0.36
n = 0.40 ` 208' Volume Provlded ~A
S= 0.010 ' AI~ ~ C . Q.LJ'f
7c = 6.39 min., by Equatlon 3-2 of Guidelines
Time Time Inc. irtens. Q Devel. Vol.In Vd.Out Staage
185 ft. Swale fiow (mIn) (sec) (Whr) (cfs) (cu ft) (cu ft) (Cu ft) .
Z1= 3.0 Fa Z2 8.56 514 2.43 0.82 425 514 -69
Z2= 3 TypeB=1.0 t
n= 0.430 Rdled = 3.5 5 300 3.18 0.81 325 300 25'==
S= 0.008 10 600 224 0.57 441 600 -159
% 15 900 1.71 0.45 483 900 -417
d= 0,381 ft, 20 1200 1.45 0.37 506 1200 -694
25 1500 1,21 0.31 515 1500 -985
A R Q Tc Tc total I Qc 30 1800 1.04 0.26 522 1800 -1278 .
======z=a =::z===== a======-- a 35 2100 0.91 0.23 526 2100 -1574
0.44 0.18 0.62 2.17 8.56 2.43 0.62 40 2400 0.82 0.21 536 2400 -1864 .
45 2700 0.74 0.19- 540 2700 •2164
Qpeak tor Case 1= 0.62 cfs 50 3000 0.68 0.17 548 3000 •2452
55 3300 0.64 0.16 565 3300 -2735
60 3600 0.61 0.15 585 3600 -3015
CASE 2 ' 65 3900 0.60 0.15 621 3900 -3279
70 4200 4.58 0.15 644 4200 -3556
Case 2 assumes a Time of ConcentratiOn less than 5 minutes so that lhe 75 4500 0.56 0,14 665 4500 -3835
peak flow =.90(3.18)(Imp. Area) = 0.33 cfs ~ 80 4800 0.53 0.13 670 4800 -4130
85 5100 0.52 0.13 697 5100 -4403
90 5400 0.50 0.13 708 5400 -4692
So, the Peak flow for the Basin Is tfie greater of the ivw flows, 95 5700 0.49 0.12 731 5700 -4969
0.62 cfs 100 6000 0.48 0.12 753 6000 -5247
~208' DRAINAGE POND CALCULATIONS ~
~ Required'208' Storage Yolume , •
Impervlous Area x.5 in I 12 (Nft ~ 206 cu ft
208' Storage Volume Provided : eu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~
Ma)dmum Storage Requfred by Bowstring 25 cu RNumber and Type of Drywelis Required 0 Single
1 Double
-j
BOWSTRING METHOD PROJECT: Rlvervua(k Tth AddfUan
PEAK FLOW CALCULATION PROJECT: Rfverwalk 7th Additlon DETENTION BASIN OESIGN BASIN: L
BASIN: L , 10-Year Deslgn Stam OESIGNER: B. Hmard - Tot. Area 1.49 Acres DATE: 5J31196
Imp. Area 6117 SF .
C = 0.33
Tlme Increment (min) 5
CASE 1 Time ot Conc. (min) 8.67
Outflow (Cis) f
145 ft. Overland Flaw Deslgn Year Flow 10 - ,
Area (acres) 1.49
Ct = 0.15 ImpeMous Area (sq ft) 6117, ,
L= 145 ft. 'C' Facta 0.33
n = 0.40 '268' Volume Provlded • .
S= 0.010 Area' C 0.492
Tc = 6.83 min., by Equatfon 3-2 of Guidelines
' Tlme Tlme Inc. Irttens. Q Devel. Vol.ln Vd.Out . Storage
185 ft. Swale ftow (mfn) (sec) (iMnr) (cis) (cu ft) (cu rt) (cu tt)
•••s~ an~ ===ea =s~----_a o=~===ma~ aaa---_sa amaza--=^ =a==_arsea,
Z1 = 3.0 Fa 72 ~ 8.67 520 242 1.19 826 520 308
Z2 = 3 Type B =1.0 '
n a 0.030 ROlled = 3,5 5 300 3.18 1:56 629 300 329'==
S= 0.008 10 600 2.24 1.10 856 600 256
15 900 1.77 0.87 937 900 37
d= 0.487 ft. 20 1200 1.45 0.71 982 1200 -218
25 1500 1.21 0.59 998 1500 S02
A R Q Tc Tc total I Qc 30 1800 1•44 0,51 1011 1800 '789 ,
==-w--==== - ^-=-W--=L= 35 2100 0.91 0.45 1019 2100 •1091
0.71 0.23 1.19 1.84 8.67 2.42 1.19 40 2400 0.81 0.40 1039 2400 •1361
45 2700 0.74 0.36. 1047 2700 -1653
Qpeak for Case 1= 1.19 cfs 50 3000 0.68 0.33 1062 3040 •1908
55 3300 0.64 031 1094 3300 -22A6
60 • 3600 0.61 0.30 1133 3600 •2467
CASE 2 65 3900 0.60 0.30 12a3. 3900 -2697
TO 4200 0.58 0.29 1248 4200 -2952
Case 2 assumes a Time of Conce ntration less than 5 minutes so that the • 75 4500 0.56 028 1288 4500 3212
peak 11ow =.90(3.18)(Imp. Area) = 0.40 cfs 80 4800 0.53 0.26 1297 4800 4503
85 5100 0.52 026 1349 5100 -3751
90 5400 0.50 0.25 1371' 5400 4029
So, the Peak flow fa the Basin Is the greater of the two fl~ovus, 95 5700 0.49 0.24 1416 5700 -4284
1.19 cfs 100 . 6000 0.48 024 1458 6000 4542
' 208' DRAINAGE POND CALCULATIONS Requlred'208' Staage Yolume ~
ImpeMous Area x.5 In 112 INft 255 cu ft ,
~ .
208' Storage Volume Provided cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
~ Ma)dmum Storage Requfred by,Bowshing 329 cu ft
,
Number and Type oi Drywells Requlred 0 Single
' 1 Double
~ L--J
BOWSTRING METHOD PROJECT: Rivelwalk 7th Addftion
PEAK FLOW CALCULATION PROJECT: Rivetwalk 7th Addftion DETENTION BASIN DESIGN BASIN; - M
BASIN: M 10-Year Design Storm DESIGNER: B. Howard '
Tot. Area 0.83 Acres DATE 5131196
Imp. Area 5332 SF ,
C ~ 0.36 Tlme Incremem (min) 5
CASE 1 T[me of Conc. (min) 8.72
Outtiaw (cfs) 1
130 ft. dverland Flow Design Year Flow 10
Area (acres) 0,83
Ct = 0.15 ImpeMous Area (sq ft) 5332 .
L= 130 ft 'C Fadar 0.36 '
n = 0.40 '208' Vdume Provlded S= 0.010 Area' C• 0299 '
Tc = 6.39 min., by Equation 3-2 of Guidelines
lime Time Inc. IMens. Q Oevd. Vd.in Vd.Out' Storage
206 ft. Surale ftaw ' (min) (sec) (fMu} (cfs) (cu R) (cu ft) (cu R)
' ==aa==== ===a===am _sam - r- a==
Z1= 3.0 Fa 72 812 523 241 0.72 , 505 523 -18
Z2 = 3 Type B =1.0
n = 0.030 Rolled = 3.5 5 300 3.18 0.95 382 300 .82
S= 0.048 10 600 224 4.67 521 600 -79
15 900 1.77 0.63 570 900 -330
d= 0.404 ft. ZO 1200 1.45 0.43 597 1200 -603
25 4500 121 0.36 607 1500 -M
A R Q Tc Tc total I Qc 30 1800 1.04 0.31 615 1900 -11 SS •
=L=== 35 2100 0.91 0.71 610 2100 -1480
0.49 0.19 0.72 233 8.72 2.41 0.72 40 2400 0.82 0.25 832 2400 -1768
45 2700 0.74 0.22. 637 7100 -2063
Qpeak for Case 1= 0.72 cfs 50 3000 0.68 0.20 646 3000 -2354
55 3300 0.64 0.19 666 3380 -2634
60 3600 0.61 0.18 889 3600 -2911
CASE 2 ~ 65 3900 0.60 0.18 732 3900 -3168 TO 4200 0.58 0.17 759 4200 -3441
Case 2 assumes a Time of Concentratlon less than 5 minutes so that the 75 4500 0.56 0.17 783 4500 -3717
peak flow =.90(3.16)(Imp. Area) = 0,35 cfs 80 4800 0.53 0.16 789 4800 -4011
85 5100 0.52 0.16 821 5100 -4279
90 5400 0.50 0.15 834 5400 -4566
So, the Peak fiow for the Basin is the greater of the two tiows, 95 5700 0.49 0.15 861 5700 -4839
0.72 cis 100 6000 0.48 0.14 887. 6000 -5113
.
Z08' DRAINAGE POND CALCULATIONS
Requlred'208' Storage Volume
= Impervious Area x.5 in I 12 INR 222 cu ft
208' Storage Volume Provlded . cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Staage Requ(red by Bowsting ' 82 cu ft
Number and Type of Drywells Required • 0 S(ngle
' 1 Double " , ~ .
BOWSTRING METHOD PROJECT: RiverwalklthAddftlon PEAK FLOW CALCULATION PROJECT: RivenNalk lth Addition OETENTION BASIN DESIGN @ASIN: N
BASIN; N 10-Year Design Starm DESIGNER: S. Howard
Tot. Area 1.02 Acres DATE: 5/31196
Imp. Area 5819 SF ' C = 0.34 Tlme Increment (mfn) 5
CASE 1 Time oi Conc. (min) 8.18 '
Outtlow (cis) 1-
95 ft. Overland Flow Des(gn Year Flaw 10
`Area (acres) 1.02
Ct = 0.15 Impervlous Area (sq ft) 5819
L= 95 ft. 'C Factor 0.34
n = 0.40 20g' Volume Provided
S = 0.010 Area' C '0.342
Tc = 5.30 min., by Equation 32 of Guidelines
Time Tfine Inc. IMerre. Q DePvd.' Vd.ln Vol.Out: Storage
266 ft. Swale flov (min) (sec) (inmr) (cfs) {cu tt1 (a ft) (a n)
Z1= 3.0 For I2 8.18 491 248 0.85 559 431 68
Z2 = 3 Type B=1.0 n= 0.030 Rolled = 3.5 5 300 3.18 1.09 437 300 137
S= 0.008 10 600 224 0.77 587 600 43
. 15 900 1.77 0.61 646 900 =254
d= 0.429 ft. 20 1 Z00 1.45 0.50 678 1200 522
25 1500 1.21 0.41 690 1500 -810
A R Q Tc Tc total I Qc 30 1800 1.04 0.36 700 1800 -1100 ,
35 2100 0.91 0.31 706 2100 •1394
0.55 0.20 0.85 2.88 8.18 2.48 0.85. 40 2400 0.82 028 720 2400 -1680
45 2700 0.74 0.25. 126 2700 -1974
Qpeak for Case 1= 0.85 cfs ` 50 3000 0.66 0.23 736 3000 •2264
55 3300 0.64 0.22 759 3300 •2541
' 60 3600 0.61 0.21 788' 3600 •2814
CASE 2 65 3900 0.60 021 835 3900 3065
70 4200 0.58 0.20 866 4200 -3334
Case 2 assumes a Time oi ConcentraBon less than 5 minutes so that the 75 4500 0.56 0.19 894 4500 -3606
peak flow =.90(3.18)(Imp. Area) = 0.38 cfs 80 4800 0.53 0.18 900 4800 -3900
85 5100 0.52 0.18 937 5100 -4163
90 5400 0.50 0.17 952 5400 4448 So, the Peak ilow tor the Basin ls the greater af the two flows, ` 95 5700 0•49 0•17 983 5700 -4117
0.85 cfs 100 6000 0.48 0.16 1012 6000 -4988
.
' 2W DRAINAGE POND CALCULATIONS
Required'208' Storage Volume
% % . = Impervbus Area x.5 in I 12 fNR 242, cu ft
208' Storage Volume Provided cu ft .
; DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Ma)dmum Storage Required by Bows61ng ' 137 cu ft
Number and Type of Drywella Requfred 0 Single
1 Double
;BOWSTRING METH00 PROJECT: Rivenwalk 7th Add'~itlon
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addklon DETENTION BASIN DESIGN BASIN: 0
BASIN: 0 10-Year Oes{gn Stam DESIGNER: B. Howard,
Tot. Area 1.41 Acres DATE: 5131196
Imp. Area 6966 SF
C = 0.34
Time IncremeM (min) 5
CASE 1 Tfine of Conc. (min) 9.00
Oumow (cis) 1
115 ft. OverSand Flow Design Year Flaw 10 ,
Area (xres) 1.41
Ct = 0.15 . ImpeMous Area (sq ft) 6966
L= 115 ft. 'C' Factor 0.34
n = 0.40 '206' Vdume Provided s = 0.010 Area ~c 0.485
Tc = 5.94 min., by Equatlon 3-2 oi Guidellnes
Time Tlme Inc. Intens. Q Devel. Vd.ln Vol.Out Staage
305 rt. Swale flow (m(n) (sec) (iNho (cfs) (cu ft) {a tt) (cxi ft)
~M~~~:~ CCII::.~«3 : C«~.9aia3 C~'L.~~.N= ~~wS=II'CII L•9:C~CC~
Zi = 3.0 For Z2 9.00 540 2.37 1.15 83'1 540 292
Z2 = 3 Type B =1.0 . '
n = 0.030 Roll2d = 3.5 t , 5 300 3.18 1.54 620 300 320 <=a
S= 0.008 ` 10 600 2.24 1.09 851 600 251
` 15 900 1.77 0.88 930 900 30
d= 0.481 ft. 20 1200 1.45 0.70 973 1200 -227
25 1500 121 0.59 988 1500 512
A R Q Tc Tc total I Qc 30 1800 1,04 0.50 1001 1800 -799 35 2100 0.91 0.44 1008 2100 -1092
0.69 0.23 1.15 3,06 9.00 2.37 1.15 40 2400 0.82 0.40 1028 2400 -1372
45 2700 0.74 0.36 1035 Z700 -1665
Qpeak for Case 1= 1.15 cfs 50 3000 0.68 0.33 1050 3000 -1950
55 3300 0.64 0.31 1081 3300 -2219
60 3600 0.81 4.30 1119 3600 •2481
CASE 2 65 3900 4.60 0.29 1188 3900 4112
70 4200 0.58 0.28 1733 4200 -2967
Case 2 assumes a Time oi Concentratfon less than 5 minutes so that the ` 75 4500 0.56 0,27 1712 4500 4228
peak flaw =.90(3.18)(Imp. Area) = 0.46 cfs 80 4800 0.53 0.26 1281 4800 -3519 ,
` . 85 5100 0.52 0.25 1333 5100 -3767
90 5400 0.50 0.24 1354 5400 4046
So, the Peak tlow for the Basin is the greater of the two flows, ~ 95 5740 0.49 0.24 1398 5700 4302
1.15 cfs 100 6000 0.48 0.23 1440 6000 -4560 % N ,
% - 208' DRAINAGE POND CALCULATIONS ~ Requlred'208' Staage Volume
= ImpeMais Area x.5 in I 12 iNft 290 cu rt
% ` 208' Storage Volume Provlded cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
% Ma)dmum Starege Requfred by BowWng 320 cu ft
' Number and Type of Drywells Required 0 Single
1 Double
BOWSTRING METHOD PR4JECT: Riverwalk7th Addkion
PEAK FLOW CALCUlATION PROJECT: Rivenralk lth AddiUon DETENTION BASIN OESIGN BASIN: P
BASIN: P 10-Year Qesign Storm OESIGNER: B. Howard
Tot. Area 0.72 Acres ~ DATE: 5131I96
Imp. Area 2379 SF , c = 0.32
% Time IncremeM (min) 5
CASE 1 Time oi Conc. (min) 8.76
Outflow (cfs) 1
135 ft. Overland Flow Design Year Fbw 10
Area (acres) 0.72 '
Ct = 0.15 Impervlovs Area (sq ft) 2379
L= 135 ft. 'C Factor 0.32 % n = 0.40 208' Volume Provided
S= 0.010 Area' C 0232
Tc ~ 6.54 min., by Equatlon 3-2 oi Guldellnes
Time Time Inc. IMens. Q Qevel. Vof.ln Vol.Out Storage
190 ft. Swale fiow (min) (sec) Onlhr) (cfs) (cU R) (cU ft) (cw ft)
Z1= 3.0 , ForZ2 8.76 525 240 0.56 394 '525 -133
7-2= 3 TypeB=1.0 n= 0.030 Rolled = 3.5 % 5 300 3.18 0.T4 29T 300
S= 0.009 ~ 10 600 224 0.51 405 600 •195
15 900 1.77 0.41 443 900 -457
d= 0.361 ft. ~ 20 1200 1.45 0.34 464 1100 -736 % 25 1500 121 028 471 1500 -1029
A R Q' Tc Tc total I Qc 30 1800 1.04 024 477 1800 -1323 .
% 35 2100 0.91 0.21 481 2100 -1619
0.39 0.17 0.56 2.22 8.76 2.40 0.56 „ 40 2400 0.82 0.19 491 2400 -1909
45 2700 0.74 0.17. 494 2700 2206
Qpeak fot Case 1= 0.56 cfs 50 3000 .0.68 0.16 501 3000 -2499
55 3300 0.64 0,15 517 3300 -2783
60 3600 0.61 0,14 535 3800 -M
CASE 2 % 65 3900 0.60 0,14 568 3900 ~331
70 4200 0.58 0.13 589 4200 -3611
Case 2 assumes a Tlme of Concentration less than 5 minutes so that the 75 4500 0,56 0.13 608 4500 -3892
peak flow =.90(3.18)(Imp. Area) = 0.16 cfs 80 4800 , 0.53 0.12 612 4800 -4188
85 5100 0.52 0.12 637 5100 -4463
90 5400 0.50 -0.12 647 5400 -4753
So, the Peak tlow for the Basln fs the greater of the two flows, 95 5700 0.49 0.11 668 5700 -5032
0.56 c(s 100 6000 0.48 0.11 688 6000 -5312
208' ORAINAGE PONO CALCULATIONS
Requlred'248' Storege Volume
Impervlous Area x.51n 112 INrt 99 cu ft
.
' 208' StoraBe Vdume Provided cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Ma)dmum Staage Required by Bowsping -3 cu ft
Number and Type of Dryweils Requlred 0. Single
i Dauble
< <
ry w -
,
BOWSTRING METHOD PROJECT; Riverwalk lth Add[Uon
PEAK FLOW CALCULATION PROJECT: Rlverwalk 7th Addfflon DETENTION BASIN DESIGN BASIN: Q
BASIN: Q 10-Year Design Starm DESIGNER: B. Howard
Tot. Area 0.61 Acre.s DATE; 5/31196 _
Imp. Area 3114 SF C = 0.35
Time Increment (mIn) 5
CASE 1 Time of Conc. (min) 7.98
Oulflow (cfs) 1'
130 R, Overland Flow Deslgn Year Flow 10
Area (acres) 0.61 Ct = 0.15 impeMous Area (sq ft) 3114 '
L= 130 ft. 'C Factot 0.35
n = 0.40 208' Volume Provided
S= 0,010 Area' C 0.213
Tc = 6.39 min., by Equation 3-2 of Guldelines
Time Time Inc. -IMens. Q Devel. Vd.U Vol.Out Storege
160 ft. Gutter tlow (min) (sec) (iNhr} (cfs) (cu ft) (cu ft) (cu ft)
eaa a:----nsa a:--sxn ^---~~~a a~ss~za sas~~ tsaz-.=~o Z1= 50.0 For 72 7.98 479 2.51 0.54 343 479 •135
72= 3.5 Type8=1.0 ,
n= 0.016 Rolled = 3.5 5 300 3.18 0.68 272 300 -28
S= 0.016 10 600 224 0.48 364 600 -236
15 900 1.77 0.36 401 900 499
d= 0.109 ft. .20 1100 1.45 0.31 421 1200 -779
25 1500 121 0.28 429 1500 •1071
A R Q Tc Tc total I Qc 30 1800 1.04 0.22 435 1800 -1365 .
- 35 2100 0.91 0.19 439 2100 -1661
0.32 0.05 0.54 1.58 7.98 2.51 0.54 ~ 40 2400 0.82 0,17 448 2400 •1952
45 2700 0.74 0.16. 451 2700 •2249
Qpeak for Case 1= 0.54 cfs 50 3000 0.68 0:14 458 3000 •2542
55 3300 0.64 0.14 472, 3300 -2828
60 3600 0.61 0.13 489 3600 -3111
CASE 2 , 65 3900 0.60 0.13 519 3900 -1=1
70 4200 . 0.56 0.12 539 4200 -3661
Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.12 566 4500 -3944
peak flow =.90(3.18)(Imp. Area) = 0.20 cfs 60 4800 0.53 0.11 560 4800 4240
% 8/~5 5100 0.5~/ 2 0.11 563 5~1~00 -4517
4 VV ~I"TYY O.W 0.11 Wr riYY '1808
% So, tfie Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.10 612 5700 -5086
0.54 cis ' 100 6000 0.48 0.10 630 6000 -5370
208' DRAINAGE POND CALCULATI4NS
' Requlred'208' Storage Vdume
ImpeMous Area x.5 ln I 12 lNft 130'cu ft
% 208' Storaye Volume Provided cu rt
` DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ;
% Ma)dmum Slorage Requlred by BowsMng : -28 cu ft
x Number and Type of Drywells Required 0 Single
' 1 Double
80WSTRING METHOD PROJECT: Rivermre(k7th Addhion
PEAK FLOW CALCULATION PROJECT: RNenKalk lth Addition OETENTION BASIN OESIGN BASIN; - R
BASIN: R 10-Year Design Storm DESIGNER: B. Howard
Tot. Area 1.71 Acres DATE: 5/31196
Imp. Area 7344 SF
C = 0.32
Tlme IncremeM (min) 5 CASE 1 Tlme oi Conc. (min) 7.98
Outtlow (cfs) 1
100 ft. Overiand Flow Design Year Flow 10 ' Area (acres) 1.71 '
Ct = 0.15 Imperviais Area (sq ft) 7344 . '
L= 100 ft. 'C' Fador 0.32 n = 0.40 208' Volume Provlded •
S= 0.010 Area' C 0.555
Tc = 5.46 min., by Equation 3-2 of Guldelines
` Tlme Tfine Inc. Intens. Q Devel. Vo1.ln Vd.Out Storage
250 rt. Gutter 11Vw • ~5 `S (min) (sec) (iMu) (cis) (cu rt) (cu rt) (cu ft)
a~ ~a~==a ~ a==== ==a e==aa _=m ==a=----= =an=ac~aa a..aa_....--
Z1= 50.0 For Z2 7.98 479 251 1.40 895 479 416
ZZ = 3.5 Type B =1.0 %
n= 0.016 Roiled = 3.5 % 5 300 3.18 1.76 709 300 409
S= 0.008 10 600 224 1,24 948 600 348
15 900 1.77 0.98 1044 900 144
d= 0.178 ft. 20 1200 -1.45 0.80 1097 1200 -103
25 1500 1.21 0.67 1117 1500 -383
A R Q Tc Tc total I Qc 30 1800 1.04 0•58 1133 1800 '667 .
====w-=_== ^-==M --=a== 35 2100 0.91 0.51 1143 2100 -957
0.85 0.09 1.40 251 7.98 2.51 W 1.40 40 2400 0.81 0.46 1166 2400 -1234
45 2700 0.74 0.41 • 1176 7100 •1524
Qpeak for Gase 1= 1.40 cfs 50 3000 0.68 0.38 1194 3000 -1806
55 3300 0.64 0.36 1230 3300 -2070
60 3600 0.61 0.34 1714 3600 •2326
CASE 2 ` 65 3904 0.60 0.33 1353 3900 •2547
70 4200 0.58 0.32 1404 4200 -2796
Case 2 assumes a Time of ConceMration less than 5 minutes so that the 75 4500 0.56 0.31 1449 4500 -3051
peak flow =.90(3.18)(Imp. Area) = 0.48 cfs 80 4800 0.53 029 1460 4800 -3340
85 5100 0.52 0.29 1519 5100 -3581
90 5400 0.50 0.28 1544 5400 -3856
So, the Peak flow tar the Basln is the greater of the two flows, 95 5700 0.49 0.27 1594 5700 -4106
1.40 cfs 100 6000 0.48 0.27 1642 6000 -4358
, . 2Q8' ORAINAGE POND CALCUTATIONS
Required 208' Storage Volume
= Impervlous Area x.5 in 1121Nft 306 cu ft
208' Storage Volume Provided cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
~Ma)dmum Storage Required by BowsMng 416 cu ft
,
Number and Type of DrywElls Requlred O.S(ngle
1 Double
-
BOWSTRINGMETHOD PROJECT: Rhieiwalk7thAdditlon
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition DETENTI4N BASIN DESIGN BASIN: R1
BASIN: R1 , 10-Year Design Storm DESIGNER: B. Hovrard
Tot. Area 0.97 Acres DATE: 5J29/96
Imp. Area 3271 SF ~ C = 0.30
Time Increment (min) 5
CASE 1 Tlme ai Conc. (min) 10.32
Outflow (cis) 1 '
135 ft. Overland Flow Desfgn Year Flow 10
Area (acres) 0.97
Ct = 0.15 ImpeMous Area (sq R) 3711
L= 135 ft. 'C Fador 0•30
n = 0.40 208' Volume Provfded ,
S= 0.010 Area • C 02M
Tc = 6.54 min., by Equatlon 32 of Guldellnea
Tlme Time Inc. IMen.s. Q Devel. Vd.ln Vd.Out Storage
236 ft. swale tlow (min) (sec) pNhr) (cis) (cu rt) (w rt) (cu R)
' ----~se~ aea===c== m°====~= a:naar.~e a--°~--: ~ra~=~ s===ca~~
Z1= 50.0 For Z2 10.32 619 2.20 0.64 531 619 -89
Z2 = 3 Type B z 1.0
n= 0.030 Rolled = 3.5 5 300 3.18, 0.93 372 300 72
S= 0.014 Swale=3.0 10 600 224 0.65 524 600 •76
• 15 900 1.77 0.52 57°2 900 -328
% 20 1200 1.45 0.42 . 596 1200 ~605
d= 0.153 ft. %
% 25 1500 1.21 0.35 602 1500 -898
A R Q Tc Tc toial I Qc ' 30 1800 1.04 0.30 608 1800 -1192 •
= 35 2100 0.91 0.26 612 2100 •1486
0.62 0.08 0.64 3.78 10.32 220 0,64 , 40 2400 0.81 0.24 623 2400 -1777
45 2700 0.74 0.22 627, 2700 -2073
Qpeak fot Case 1 = 0.64 cfs 50 3000 0.68 0.20 635 3000 -2365
55 3300 0.64 0.19 654 3300 •2646
60 3600 0.61 0,18 678 3600 •2924
CASE 2 ' 65. 3900 0.60 '0.17 718 3900 -3182
70 4200 0.58 0.17 744 4200 -3456
Case 2 assumes a Time oi Concentraton less than 5 minutes so that the 75 4500 0.56 0.16 766 4500 -3732
peak flaw =.90(3.18)(Imp. Area) = 0.21 cfs 80 4800 0.53 0.15 773 4800 -4027
85 5100 0.52 0.15 804 5100 -4296
% 90 5400 0.50 0.15 816 5400 -4584
So, the Peak Bow for the Basfn Is the greater of the two flows, % 95 5700 0.49 0.14 843 5100 -4851
0.64 cfs 100 6000 0.48 0:14 867 6000 -5133
208' ORAINAGE POND CALCUlATIONS
~ Requfred'208' Storage Volume
Impervious Area x.5 In ! 12 fNft 136, cu ft
208' Storage Volume Provided cu ft
~ DRYWELL REQUIREMENTS -10YEAR DESIGN STORM
" Maaximum Staage Required by Bouvstflng 72 cu ft
Number and Type oi Drywelis Required 0 Single
1- Double
. i
- - ` r ~ , . -
BOWSTRING METHOD PROJECT: Rhrerwalk 7th Additlon
PEAK FLOW CALCULATION PROJECT: Rfvenxalk lth Addidon DETENTION BASIN DESIGN BASIN; RT
BASIN: RT 1QYear Design Stortn DESIGNER: B. Haward
Tot. Area 2.52 Acres
Imp. Area 14636 SF DATE: 5129m
C = 0.34
T(me Increment (mIn) 5
CASE 1 Tlme of Cone. (min) 7.57
Outfiaw (cfs) 1
135 ft. Overland Flow Des{gn Year Flow 10
Area (acres) 252
ct = a~ s r, Impervfaus Area (sq R) t~as3s
L= 135 ft. `'C Factor 0.34
n = 0.40 '208' Volume Prorrided
S= 0.010 Area' C 0.857
, . .
Tc = 6.54 min., by Equation 3-2 of Guidelines
Time Time Inc. IMens. Q Devel. Vol.ln Vd.Out Staage
xis ft. Gutter flow (min) (sec) pnmr) (Cfs) (a rt) (a n) (w ft)
;
Z1 = 3.0 For Z2 ~ ~_..a_.. ea-=-=a= :n~~--- s-- ==a=ea - =a
7.57 454 259 222 1349 454 895
Z2 = 3 Type B L 1.0 '
n= 0.016 Rolled = 3.5 5 300 3.16 272 1095' 300 795
S= 0.014 10 600 2.24 1.92 1448 600 848
15 900 1.77 1.5s2 1599 900 699
d= 0.440 ft. 20 1200 1.45 124 1683 1200 483
25 1500 121 1.04 1715 1500 215
A R Q Tc Tc toral I Qc 30 1800 1.04 0•89 1142 1800 -58
35 2100 0.91 0.76 1756 2100 ~42
0.58 0.21 2.71 1.03 7.57 2.59 2.22 ` 40 2400 0.82 0.70 1795 2400 -605 % 45 2700 0.74 0.63. 1810 2700 -890
Qpeak for Case 1= 222 cfs SO 3000 0.68 0.58 1838 3000 -1162
55 3300 0.64 0.55 1894 , 3300 -1406
, 60 3600 0.61 0.52 1982 3600 -1638
CASE 2 65 3900 0.60 0.51 2084 3900 -1816
% 70 4200 0.58 0.50 2164 4200 -2036
Case 2 assumes a Time ot Concentration less than 5 minutes so that lhe 75 4500 0.56 0.48 2233 4500 -2267
peak flaw =.90(3.18)(Imp. Area) = 0.96 cfs 80 4800 0.53 0.45 2250 4800 -2550
. 85 5100 0.52 0.45 2341 5100 -2159
' 90 5400 0.50 0.43 2380 5400 ~020
So, the P~k tlow for the Basin ia ihe greater af the lwo fiows, 95 5700 0.49 0.42 2458 5700 ~242
2.22 cfs 100 6000 0.48 0,41 2531 6000 -3469
% . 208' DRAINAGE POND CALCULATIONS
Required'208' Storage Vdume
Impervfous Area x.5 In 112 INtt 610 cu R
208' Storage Volume Provided ' cu R
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM '
Mmdmum Stomge Requhed by Bowsfflng 895 w RNumber and Type of Drywells Required ' 0 Single
1 Dauble
. '
;
BOWSTRING METHOD PROJECT: RNervvalk 7th AddiUon
PEAK FLOW CALCULATION ' PROJECT: Rivernralk lth AddiUon 'DETENTION BASIN DESIGN BASIN: S
BASIN: S1QYear Design Storm DESIGNER: B. Haward
Toi. Area 0.60 Acres DATE: 5131'196 ,
Imp. Area 4651 SF C = 0.41
Time IncremeM (min) 5
CASE 1 Time o! Conc. (mIn) 6.91
OWlow (cfs) 1
60 ft. Overland Flow Design Year Flow 10-
Area (acres) 0.6 Ct = 0.15 Impervlous Area (sq ft) 4651
L= 60 ft. ' 'C Factor 0.41
n = 0.40 20B' Vdume Provided
S= 0.010 ` Area' C 0.244
`
x
:
Tc = 4.02 min., by Equation 3-2 of Guldefines
• ~ Time Time Inc. IMens. Q Deve1. Vol.ln Vol.Out Staage
250 ft. Swale flow (mIn) (sec) ((Nhr) (cis) (cu ft) (cu R) (cu ft)
II~~7:: ~ ~ C~.:C~0~7~ ~~IIII. ~II~II C~ mS~a~~~ ••^~~~3i'iQ C~C:
Z1= 3.0 For Z2 6.91 415 2.70 0.66 365 415 -49
Z2 = 3 Type B =1.0
n= 0.030 Rolled = 3.5 5 300 3.18 0.78 312 300 12
S= 0.008 10 600 224 0.56 . 405 600 •195
15 900 1.77 0.43 450 900 -450
d= 0.390 R ' 20 1200 1.45 0.35 474 1200 726
25 1500 121 0.30 484 1500 -1016
A R Q' Tc Tc total I Qc 30 1800 .1.04 0.25 493 1800 -1307 _ 35 2100 0.91 a.n ass 2100 -1602
0.46 ats 0.66 2.89 6.91 2.70 0.66 ao 2400 0.82 0.20 soe zaoo •1892
45 2700 0.14 0.18 513 2700 -2187
Qpeak (or Case 1= 0.66 cfs 50 3000 0.68 0.17 521 3000 -2419
55 3300 0.64 0.16 537 3300 -2763
sa 3600 0.61 0.15 55~ 3600 -3043
CASE 2 65 3900 0.60 0.15 592 3900 -3308
70 4200 0.58 0.14 614 4200 -3586
Case 2 assumes a Time of Concentrabon less tfan 5 minutes so lhat the 75 4500 0.56 0.14 634 4500 -3866
peak flow =.90(3.18)(Imp. Area) = 0.31 cfs 60 4800 0.53 0.13 639 4800 -4161
SS 5100 0.52 0.13 665 5100 4435
90 5400 0.50 0.12 676 5400 -4724
So, the Peak flow for the Basin is the greater of the two 8ows, 95 5700 0.49 0.12 698 5700 -5002
0.66 cfs ; 100 6000 0.48 0.12 719 6000 -5281
208' DRAINAGE POND CALCULATIONS '
Required'208' Starage Vdume
= Impenrlous Area x.51n ! 12 iNft , 194 cu ft
• 208' Storage Volume Provided cu ft
, DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ;
Ma)dmum Storage Requlred by Barwstrfng , 12 cu ft
~
Number and Type of Drywelis Requlred 0 S(ngle
1 Double'
. . , .
BOWSTRING METHOD PROJECT: RlvetwaUclth Addition
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Add'~lon DETENTION BASIN DESIGN BASIN: T ~
BASIN: T 10-Year Qesign Storm DESIGNER: B. Howard,
Tat. Area 0.81 Acres DATE: -51311'96
Imp. Area 7292 SF C = 0.38 . Time Increment (min) 5
CAS E 1 Time oi Conc. (min) 830 Oumow (cfs) 1 90 ft. Overland Flow Design Year Flow 10
~ Area (acres) 0.81
ct = 0.15 Impervlous Area (sq R) 7292
L= 90 R. 'C Fadar 0.38
n = 0.40 208' Volume Prov(ded '
S= 0.010 Area' C 0.306
Tc = 5.13 min., by EquaGon 3-2 of Guldelines
Time Time Inc. Inters. 4 DeveL Vd.ln Vol.Out Storage
270 rt. Gutter flow (m1n) IsW) (lnfir) {cfs) (cu ft) (cu n) (cu ft)
Z1= 50.0 For Z2 8.30 498 247 0.75 542 498 ' 4
7.2 = 3.5 Type B =1.0 k . . '
n= 0.016 Rolled = 3.5 5 300 3.18 0.97 390 300 90
S= 0.008 10 600 2.24 .0.68 526 600 •14
is soo 1.77 0.54 sn soo -323
d= 0.141 ft. ' ZO 1200 1.45 0.44 606 1200 -594
% 25 1500 121 0.37 818 1500 -884
A R Q Tc Tc total I Qc 30 1800 1.04 0.32 525 1800 •1175 ,
- - - - } 35 2100 0,91. . 0.28 630. 2100. -1470
0.53 0.07 0.75 3.17 8.30 2.47 0.75 • 40 2400 0.82 0.25 643 2400 .1757
% 45 2700 0.74 0.23. ' 648 2700 -2052
Qpeak tor Case 1= 0.75 cfs 50 3000 0.68 021 657~ 3000 -2343
55 3300 0.64 020 877 3300 -2623
% 60 3600 0.61 0.19 701' 3600 -2899
CASE 2 , 65 3900 0.60 0.18 745 3900 -3155
70 4200 0.58 0.18 773 4200 -3427
Case 2 assumes a Time of Concentration kss than 5 minutes so that tlhe , 75 4500 0.56 0.17 798 4500 -3702
peak flow =.90(3.18)(Imp. Area) ~ 0.48 cis ' 80 4800 0.53 0.16 803 4800 -M7
85 5100 0.52 0,16 836 5100 -4264
90 5400 0.50 0.15 849 5400 -4551
So, the Peak tlow for the Basin Is the greater oi the two flows, 95 5700 0,49 0.15 877 5100 -4823
0.75 cfs 100 6000 0.48 0.15 903 .6000 -5097
L
208' DRAINAGE POND CALCULATIONS
'Required'208' Starage Vofume
= Impervlous Area x.51n 112 INft 304 cu ft
208' Storage Volume Pravided ~ cu ft
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM `
Ma)dmum Storage Required by Bowstring i 90 cu ft
Number and Type oi Drywells Requlred 0 Single
' 1 Double
BOWSTRING METHOD PROJECT: Rlvenkalk7thAddfflon.
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Additfon DETENTION BASIN DESIGN BASIN: ' U
BASIN: U 10-Year Design Storm DESIGNER: B.,Howatd
Tot Area 4.13 Acres DATE: 5131186
Imp, Area 10363 SF C = 022 Time Increment (min) 5
CASE 1 Tlme of Conc. (min) 8.78
Outflaw (cfs) 2
125 ft. Overland Flow Design Year Flow 10
Area (acres) 4.13
Ct = 0.15 Impervlous Area (sq R) 10063
L= 125 ft. 'C' Facta 0.22 ,
n = 0.40 ` '208' Volume Provided '
S= 0.010 ° Area • C 0.893
Tc = 6.24 min,, by Equation 3-2 of Guidelines '
T[me Time Inc. Intens. Q Devel. Vd.in Vol.Out Storage
280, ft. Gutter 11ow (min) (sec) (inmr) (cfs) (cxU tt) (cu ft) (cu rt)
-=--..aaaa _..a==°-= ==a ~waa _ =s~a rs=-a---- aac- -
Z1= 50.0 For Z2 8.78 527 2.40 214 1513-- 1053 460
Z2 = 3.5 Type B =1.0 ~ n= 0.016 Rolled = 3.5 5 300 3.18 2.84 1142 600 542
S= 0.008 10 600 2.24 2.00 1558 1200 358
. Is soa 1.77 1.58 »os 1e00 -94
d= 0.209 ft. 20 1200 1.45 1.29 1186 2400 -614
25 1500 1.21 1,08 1814 3000 -1186
A R Q Tc Tc total I Qc 30 1800 1.04 0.93 1838 3600 •1762 .
L====-=== 352100 0.91 0.81 1852„ 4200 -2348 .
1.16 0.10 2.14 2.53 8.78 2.40 2.14 40 2400 0.82 0.73 1889 4800 •2911
45 2700 0.74 0.66 - 1903 5400 -W7
Qpeak for Cese 1 a 2.14 Cfs 50 3000 0.68 0.81 1930 8000 -4070
55 3300 0.64 0.57 1988 6600 4612
60 3600 0,61 0.54 2059 7200 -5141
CASE 2 65 3900 0.60 0.54 2166 7800 -5614
70 4200 0.58 0.52 2268 8400 -6132
Case 2 assumes a Time of Concentratlon less than 5 minutes so that the , 75 4500 0,56 0.50 2340 9000 4660
peak flow =.90(3.18)(Imp. Area) = 0.68 cfs , 80 4800 0.53 0.47 2351 96W -7243
, 85 5100 0.52 0.46 2451 10200 •7749
: so saoo 0.50 0.45 2491 10800 -am
So, the Peak flow for the Basln is the greater oi the two flaws, ' . 95 5700 0.49 0.44 2573 11400 41827
2.14 cfs } 100 6000 0.48 0.43 2649 12000 -9051
208' DRAINAGE POND CALCULATIONS :
Requ(red'208' Storage Volume .
= Impetvious Area x.5 In ! 12 Wft . 432 cu ft
208' Staage Volume Provided i cu ft
DRYWELL REQUIREMENTS • 10 YEAR DESIGN STORM '
Ma)dmum Storage Required by Bowstring 542 cu ft
5 ♦
• Number and Type of Oryw+efls Requfred 0 Single
, 2 Dauble
. ~ ' .
L-J l
BOWSTRINd METHOD PROJECT: Rlvetwalk 7th Additlon
PEAK FLOW CALCULATION PROJECT: Rivemafk 7th AddiUon DETENTION BASIN DESIGN BASIN:: V
BASIN: V 10-Year Design Storm DESIGNER: B. Houvard
Tot. Area 1.85 Acres DATE: 5131/86
Imp. Area 9909 SF
C ~ 0.34
Tlme Incmment (min) 5
CASE 1 Time oi Conc. (mfn) 8.86 '
Outflow (cis) 1 -
130 ft. Overland Flow Qeslgn Year Flow 10.
~ Area (acres) 1.85.
Ct = 0.15 Impervlous Area (sq ft) 9909 ' L= 130 ft. : 'C Factor 0.34
n = 0.40 208' Vdume Provided '
S= 0.010 ; Area ` C 0.633
: Tc = 6.39 min., by Equadon 3-2 of Gufdelines
Tirne Time Inc. Intens. Q Devel. Vol.ln Vd.Out Storage
250 ft. Gutter flow (min) (sec) (Infir) . (cfs) (cu rt) (cu ft) (cu ft)
msa.--~-
Z1 = 50.0 Fot Z2 k ^8.86 532 239 ^ 1.51 1078 532 546
Z2 = 3.5 Type 8 =1.0 }
n= 0.016 Rolled = 3.5 ` 5 300 3:18 2.01 809 300 509 S= 0.008 ~ 10 600 224 1.42 1107 600 507
` 15 900 1.77 1.12 1211 900 311
d= 0.183 ft. % 20 1200 1.45 0.92 1267 1200 67
' 25 1500 1.21 0.77 1287 1500 •213
A R Q Tc Tc total I Qc 30 1800 1.04 0.66 1304 1800 -496 ,
-=a=====- zs=====_= % 35 2100 0.91 0.58 1314 2100 •786
0,90 0.09 1.51 2.47 8.86 2.39 1.51 40 2400 0.82 0.52 1340 2400 •1060
45 2700 0J4 , 0.47 . 1349 Z700 -1351
Qpeak (or Case 1= 1.51 cfs 50 3000 0.68 0.43 1369 3000 -1631
' 55 3300 0.64 0.41 1410 3300 •1890
60 3600 0.61 0.39 1460' 3600 -2140
CASE 2 65 3900 0.60 0.38 1550. 3900 -2350
70 4200 0.58 0.37 1608; 4200 -2592
Case 2 assumes a Time of ConcentraUon less than 5 minutes so that the 75 4500 0.56 0.35 1659; 4500 -2841
peak flaw =.90(3.18)(Imp. Area) = 0.65 cis ; 60 4800 0.53 0.34 1671; 4800 -3129
. 85 5100 0.52 0.33 1738. 5100 -3362
x 90 5400 0.50 0.32 1766; 5400 -3634
So, the Peak Ilaw for the Basln is the greater ci the lwo flows, 95 5700 0.49 0.31 1824 : 5700 -3878
1.51 cfs 100 6000 0.48 0.30 1878 6000 -4122
i i
. •
208' DRAINAGE POND CALCULATIONS ' Required'208' Storage Volume = ImpeMous Area x.5 In I 12 M 413 cu ft
A
•,208' Storage Volume ProvEded cu ft
' DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM ~ Ma)dmum Storage Required by Bowsaing 548 cu ft
Number and Type of DryweUs Requlred 0 Single
, 1 Double
BOWSTRING METHOD PROJECT: Rlveiwalk 7th AddlUan
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Adddion DETENTION BASIN DESIGN BASIN: W .
BASIN: W 10-Year Design Storm DESIGNER: B. HowaM
Tot. Area 0.36 Acres DATE: 5131196
Imp. Area 2829 SF ' .
C = 0.41 Time Increment (mfn) 5 .
CASE 1 Time of Canc. (min) 727
outnow (cis) 03
140 ft. Overland Flow Design Year Flow 10 .
Area (acres) 0.36
Ct = 0.15 Impervbus Are,a (sq ft) 2829
L= 140 ft. ~ 'C Factor 0.41
n = 0.40 '208' Volume Provided S= 0.010 Area' C 0.148
ti
Tc = 6,68 min., by Equation 3-2 of Guldeiines
T(me Tims Inc. Inters. Q Devel. Vol.ln Vol.Out Storage
130 ft. Gutter flow (min) (sec) pNho (cfs) (cu ft) (cu R) (cu ft)
Z1= 50.0 For 72 727 436 264 0.39 228 131 97
7-2= 3.5 TypeB=1.0
n= 0.016 Rolled = 3.5 5 300 3.18 0.47 189 90 99
S= 0.159 - 10 600 2.24 0.33 248 180 68
Is soo 1.77 0.26 275 zro s
d= 0.063 ft. ZO 1200 1.45 0.21 289 360 -71
25 1500 1.21 0.18 295 450 -155
A R Q Tc Tc total I 4c 30 1800 1.04 0.15 300 540 -240 .
35 2100 0.91 0.13 3ai .630 lw
0.11 0.03 0.39 0.59 7.27 2.64 0.39 40 2400 0.82 0.12 309 TZO -411
45 2700 0.74 0.11 312 810 -498
Qpeak for Case 1= 0.39 cis 50 3000 0.68 0.10 317, 900 -583
55 3300 0.64 0.09 327 990 463
60 3600 0,61 0.09 338 1080 •742
CASE 2 ` 65 3900 0.60 0.09 359 1170 -811
70 4200 0.58 0.09 373 1260 -887
Case 2 assurnes a Time oi ConcenVatlon less than 5 minutes so that the 75 4500 0.56 0,08 385 1350 M
peak flow =.90(3.18)(1 mp. Area) = 0.19 cfs 80 4800 0.53 0.08 388 1440 -1052
85 5100 0.52 0.08 404 1530 -1126
90 5400 0.50 0.07 411 1620 -1209
So, the Peak flow for the Basin Is the greater of the iwo 8aws, 95 5700 0.49 0.07 .424 1710 -1286
0.39 -cfs 100 6000 0.48 ' 0.07 437 1800 -1363
208' DRAINAGE POND CALCULATIONS
Required'208' Staage Volume Impervious Area x.5 in ! 12 fNft 118 'cu ft
208' Storage Volume Provided • cu ft
I
ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM I
MaAmum Staage Required by BoMrsbing . 99 cu ft ,
Number and Type of Drywells Requlred ' 1 Single
' 0 Double '
.
BOWSTRIN(3 METH00 PROJECT: Riverwalk lth AddiUon
PEAK FLOW CALCULATION PROJECT: Riverwalk lth Addftion DETENTION BASIN DESIGN BASIN: X
BASIN: X 10-Year Oeslgn Stortn DESIGNER: B. Hawanf
Tot. Area 0.12 Acres ' DATE: 5131196
Imp. Area 1609 SF .
C = 0.50
Time Inaement (min) 5 .
CASE 1 Time of Conc. (min) ' 5.42
Outflow (cfs) 0.3
60 ft. Overtand Flow Design Year Flow 10
Area (acres) 0.12
Ct = 0.15 Impenious Area (sq R) 1609
L= 60 R. 'C Factor 0.50
n = 0.40 208' Volume Pravided
s= 0.010 aree • c 0.060
Tc = 4.02 min., by Equation 3-2 oi Gufdellnes
Time Time Irtc. Intens. Q Devel. Vol.in Vd.Out Staage
so R. swale eow (min) Isec) prVhr) lcfs) (cu rt) (ai rt) (cu rt)
Z1= 3.0 Fot Z2 5.42 325 3.07 0.18 80 98 47
72 = 3 Type 8=1.0
n= 0.030 Rdled = 3.5 5 300 3.18 0.19 77 90 -13
S= 0.009 Swale=3.0 10 600 2.24 0.13 95 180 -85
15 900 1.71 0.11 107 270 -163
d= 0,235 ft, ZO 1200 1.45 , 0.09 114 360 •246
25 1500 121 0.07 117 450 -3M
A R Q Tc Tc total I Qc 30 1800 1.04 0.06 119 540 -421 .
=z=== = 35 2100 0.91 0.05 121 630 -509
0.11 0.11 0.18 1.40 5.42 3.07 0.18 40 2400 0.82 '0.05 124 720 -596
45 2100 0.74 0.04 • 125 810 -685
Qpeak for Case 1= 0.18 cts , 50 3000 0•68 0•04 127 900 -173
55 3300 0.64 0.04 131 990 -859
60 3600 0.61 0.04 136 1080 -944 '
CASE 2 65 3900 0.60 0.04 144 1170 •1026
~,,,r , 70 4200 0.58 0.03 150 1260 -1110
Case 2 assumes a Time of ConceMratlon less than 5 minutes so that the 75 4500 0.56 0.03 155 1350 -1195
peak flow =.90(3.18)(Imp. Area) = 0.11 cfs 80 4800 0.53 0.03 156 1440 -1284
85 5100 0.52 0.03 163 15m -1367
90 5400 0.50 0.03 165 1620 -1455
So, the Peak 8ow tor the Basin is the greater of the two flows, `h 95 5700 0.49 0.03 171 1710 -1539
0.18 cfs 100 6000 0.48 0.03 176 1800 -1624
~
208' ORAINAGE POND CALCULATIONS
` Required'208' Storage Volume = Impervious Area x.5 in 1121Nft ' 67. cu ft
: 208' Storage Volume Provided ' cu ft
; DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Maximum Storege Requf* by 8owsbing ' -13 cu ft
c
Numbei and Type ot Drywells Requlred ~ 1 Slrigle
0 Double
. . . ' . .i .1. n.Gr : A ' . 1!.+.. 1M1~GF. ry. , . .
BOWSTRING METHOD PROJECT: RMuwalk 7th AddRfon
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addiflon DETENTION BASIN DESIGN @ASIN: Y1 .
BASIN: Y1 1QYear Deslgn Storm DESIGNER: B. Howard
Tot, Area 0.55 Acres DATE: 6/3196'
Imp. Area 14592 SF C = 0.58
Tfrne Incremerd (min) ' S'
CASE 1 T(me of Conc. (mfn) 5,00 Outflow (cfs) 0 30 ft. Overland Flow Design Year Flow 10 '
Area (aae.s) 0.56 Ct = 0.15 Impervious Area (sq ft) 14582 '
L = 30 ft. 'C Facta 0.
n = 0.02 208' Volume Provided S= 0,020 Area • C 0.319
Tc = 0.31 min., by Equatlon 3-2 at Guldellnes
`Tfine Time Inc. ntens. Q Devel. Vol.in Vo1.0ut Staage
87 ft, Gutter tiow z` (min) (sec (INhr) (cfs) (cu ft) (cu ft) (cu ft)
e~-=a=~e ~z - ~_-==a =a=~..=a= ~aa = ==as3raaa u=--
Z1 _ 50.0 ForZ2 5.00 300 3.18 ~1.01 408 0 y 408 .
72- 1 TypeB _ -1.0 ,
n= 0.016 Rolled = 3.5 300 3.18 1.01 408 0 406
S= 0.008 10 600 2.24 0.71 502 0 502
15 900 1.77 0.56 566 0 566
d= 0.161 ft. 20 1200 1.45 0.46 602 0 602
25 1504 1.21 0.39 618 .0 618
A . R . . Q . Tc Tc total . . I - Qc . -30 - . '1800. . ' 1.04 - -'.0:33 631 631 ' .
s:~== 35 2100 0.91 029 639 0 639
0.66 0.08 1.01 0.94 5.00 , 3.18 .1.01 . ~400
:.t,' y i!.:.^ .e~ .:f' 4F,~; , ,5.} Nr ,5.,b%,•' ;5~+.~,(p~Sy'jA %4fx:t. / s: e1
,,d {~1~5:, `:.~ST'~' h~ t' •y•.yIV,,•: . ,Y;4..~:;..lJ;` ~'~J u5 H S L%:M1' ~ ,v~~,~'~yc ir'4w' i`Yr~iw.Y.T•'""+~~ ,G,
~ ~;•w ~i..s '
Y~~'...'l`'•,,..~,r.,'i~l^,wa;M~ti l,lr ; ~a. .,w~ • , ~r • ~~~~e • ~r..:~' ~ lra:/" •y•t .Y>>M. rrn.~"S:'r, ~ `',2.,,. ft' "61►'iti"~''H -im ~,'.,:-~i.,,,~i.
t3 , ~
Qpeak~forCase 1 ~ ~.OI Ci1rJ , r.' • , , ~O'',,,^,•-^l„w ~ y.
JJ JJ1J1/ 0.64 OwGI VTd, 0 695
60 3600 0.61 0.19 720 0 720
CASE 2 ` 65 3900 0.60 0.19 766 0766 % TO 4200 0.58 0.19 796 0 796
Case 2 assumes a Time of Concentration less than 5 minutes so that t 75 4500 0.56 0.18 822 0 822
peak flow =.90(3.16)(Imp. Area) = 0.96 % 80 4800 0.53 0.17 629 0 829 % ~ 85 5100 0.52 -0.17 863 0 863
% , 90 5400 0.50 0.16 678 0 878
So, the Peak flow for the Basin is the greater of the Nuo fl, r 95 5700 0.49 0.16 907 0 907
1.01 cfs % 100 6000 0.48 0.15 934 0 934
208' DRAINAGE POND CALCULATIONS
~ . .
Required'208' Starage Volume , .
~ Impervious Area x.S In 1121Nft 608,cu ft
~ 208' Storage Volume Provided cu ft
% DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
Ma)dmum Storage Required by Bovusting 863 cu ft
.
~
Number and Type of Drywells Requlred 0 Single
' ERR Double
. BOWSTRING METHOD PROJECT: Rivennralklth Addftlon
PEAK FLOW CALCULATION PROJECT: Rivenwafk lth Addftlon DETENTION BASIN DESIGN BASIN: Y2
BASIN: Y2 ' 10-Year Desfgn Stonn DESIGNER: B. Howard
Tot. Area 0.72 Acres "L OATE: 5/31196
Imp. Area 19236 SF %
C = 0.59 t %
Time IncremeM (min) 5
CASE 1 `Tlme of Conc.-(min) 5.00
x ` Otrttlouy (cfs) C.p~
30 ft. Overland Flow Design Year Flow 10 Area (acres) 0.72
Ct = 0.15 Impenrious Ar~ (sq ft) 19236
L= 30 ft. 'C' Factor 0.59
n = 0.02 208' Yalume Provided
S= 0.020 Area' C 0.425
r Tc = 0.31 min., by Equation 3-2 of Guldelines .
Time Time Inc. Inters Q Devel. Vd.ln Vd.Out Storage
114 ft. Gutter 8ow (min) (sec) 'flyNhf) (cis) (cu R) (cu ft) (cu ft) % = ~ ==a~ - _s a==-~-~=a ==as-° ~ --a°=~a : ~s=== =
Z1 = 50.0 For72 5.00 3.18 N1.35 543 0 543
Z2 = 1 Type B- 1.0
n= 0.016 Rolled = 3.5 5 300 3.18 1.35 543 0 543
S= 0.008 10 600 2.24 0.95 668 0 . 668
~s soo 1.77 a~~ 753 a 753
'
d= 0.179 ft. % /20 1200 1:45 0.62 802 0 .802
~ 25 1500 121 0.51 813 0 823
%
A R Q Tc Tc total I Qc 30 1800 1.04 0.44 840 0 840 .
i 35 2100 0.91 0.39 851 0 851
0.62 0.09 1.35 1.15 5,00 3.18 1.35 40 2400 0.82 0.35 872 0 872
45 2700 0.74 0.31. 881 0 881
Qpeak for Case 1= 1.35 cfs 50 3000 0.68 0.29 896 0 896
~ 55 3300 0.64 0.27 925 0 925
' 60 3600 0.61 0.26 959 0 959
CASE 2 65 3900 0.60 0.25 1020 0 1020
~ 70 4200 0.58 0.25 106b 0 1060
Case 2 assumes a Time of Concentration less than 5 minutes so t the 75 4500 0.56 0.24 1095 0 1095
peak flow =.90(3.18)(Imp. Area) = 1cfs ,60 4800 0.53 0.23 1104 0 1104
85 5100 0.52 0.22 1149 0 1149 <=a
90 5400 0.50 4.21 1169 0 1169
95 5700 0.49 0.21 1208 0 1208 .
So, the Peak 8ow for the Basin is the greater of the o fl
1.35 cis 100 6000 0.48 0.20 . 124,4 0 1244
208' DRAINAGE POND CALCULATIONS ~ Required'208' Storage Volume
Impervfous Area x.5 In I 12 INft 802 cu ft
,
208' Storage Volume Provided cu ft
MIM
DRYWEII REQUIREMENTS -10 YEAR DESIGN STORM
Ma)6mum Storage Required by Bowstring 1149 cu ft
Number and Type oi DryweUs Requ(red 0 Slrtgle
% ERR Double.
r ~
~
kBOWSTRING METHOD PROJECT: Rivetwalk7th Additlon
PEAK FLOW CALCULATION PROJECT: Rivemalk Tth Addifion DETENTION BASIN DESIGN BASIN: Y3 .
BASIN: Y3 10-Year Des(gn Storm DESIGNER: B. Howard
Tot. Area OZt Acre.s „ DATE: 613W
Imp. Area 5341 SF %
C = 0.56 Time increment (mfn) 5
CASE 1 . Time oi Conc. (min) 5.00
' Outflow (cfs) 0 .
30 ft. Overland Flow Deslgn Year Flow '10
Are,a (aaes) 0.21
Ct ~ 0,15 ' ImpeMous Area (sq ft) 5341 -
L= 30 ft. 'C Factor 0.56
n = 0.02 "208' Valume Provfded S= 0.010 , Area' C 0.118
Tc = 0.38 min., by Equation 3-2 of Guidelines }~„R'
Time Time Inc. IMens. Q Deuel. Vd.in Vo1.0ut Storage
58 ft. Gutter flaw r?~., z`,. (min) {INh* (cts) (cu ft) _(cu ft) (cu ft)
Zt = 50,0 For Z2 300 3.18 0.37 150 0 150
Z2 = 1 Type B =1.0
n= 0.016 Rolled = 3.5 5 300 3.18 0.37 150 0 150
S = 0.008 10 600 224 0.26 185 0 185
M-1 15 900 1.77 0.21 209 0 209 i d= 0.110 ft. 1200 1.45 0.17 712 0 222
,2.ti\, ,2:`~.
1500 1.21 0.14 228 o 228
A R - Q Tc Tc total < 1800'• . . . -1•.04 ' . . ~0:12'~':;' 733
= --=`r==- ; 35 2100 0.91 0.11 236 0 236
.,,,241~Y,:
L 0.31 0.05 ~ 0.37 0.81 73 ,.00},J3.),8`~ , 0 37 ~ ,40 yµ2400 : " • - . , .L
^l•..h+RS~~"~~'V '1,r,,:;,`Aw'" •r'•i•~iry;d; ;;rG""i1fr;..r// h~t"~ Y',p~~ \ ~ IJ'ClA+:i y ,~i.~~ .~i~.'=+'~ y,}4 ~t'',~r'f.•T7',,~
,1'„. ;~•vt~,';k.~~.^"~qtiC;~~r~".tiy~.''~1r~t.•t!, u,.;ti~l~i; '~'ti'ZJ, • r,•:v.r a v , ~5~. , • ~p . t . , , . ,
. . . . • , . . . f ~ I`Sy; 1~~... H •h1
• , ' ~
Qpeak for Case 1 _ - 0.37 cfs V 5p . 3000' 0, 0:08'0 248
~ 55 3300 0.64 0.08 256 0 256
\N .'60 3600 0.61 0.47 266 O 266
CASE2 ~ 65 3900 0.60 0.07 282 0 282
'~"70 4200 0.58 0.07 293 0 293
~i.
Case 2 assumes a Time of ConcenUatlon less thanminutes so that ~e • 75 4500 0.56 0.07 303 0 303
peak flow =.90(3.18)(Imp. Area) = 0.35 cfs r~N 80 4800 0.53 .0.06 306 0 306
~'~x„~ 1 85 5100 0.52 0.06 318 0 318
i: 90 5400 0.50 0.06 324 0 324
So, the Peak flow for the Basln is th greater of the tuvo flows, 95 5700 0.49 0.06 334 0 334
0.37 cis ~ ti~, 100 6000 0.48 0.06 344 0 344
208' DRAINAGE POND CALCULATIONS
µ Required'208' Storage Volume
ImpeMous Area x.5 ln 112 iNR 22$ cu ft
~
~~~208' Storage Volume Provlded ; cu ft
~ %ORYWELL REQUIREMENTS -10 YEAR DESIGN STORM t
MaAmum Storage Required by BowsMng ; 318 cxi R
Number and T of D Ils R ired ' 0 S(ngle
~ ~ ~ ERR Double
~ ~L~SIS
~
C-UgB DROP
_l
~
.
~
s~
~
~
~
~
~
ition Ptat Dr~nage Report
` ' aik 7th A~
River►v
, -~Camp~y
Ini~ pacific Engineer~n8
~
. , . ,
CURB INLET CALCULATIONS
Curb Inlet Depression = 2 in,
Standard Curb Inlet Length = 4 ft.
Upstream 10-Yr. Gutter Roughnes Reciprocal Depth Length
Curb Inlet Impervious Peak Flow Slope Coeff. Cross slape of Flow Required Sub-Basin Station Rll Area c.f.s, S n Z Zln d* Qa/la** Q/~Qalla) Remarks
, ~ ~ . - _ . . . , _ - . e . _
0. 28+72 L 3114 0.57 0.0159 0.0160 50 3125 0.11 0.074 7.72 Need 2 curb drops
W 28+72 R R 2829 0.43 0.0159 0,0160 50 3125 0.10 0.066 6.47 Need 2 curb draps
Calculated per Figure 18 of Guidelines
Calculated per Figure 16 of Guidelines
A 4 foot curb drop with a 6" gutter has a capacity of 4:0 cfs in sump condition. .
- ,
z-,
j -
I~
l ~
I l
r
i
, J
ri `
FIGURES
~ -
;
.
~
~
.
~
I~
ii
- .
~
Inland Pacific Engineering Company Rivenvalk 7th Addition Plat Drainage Report
~
~
~
' -
~
~
,
. A5 L
ON
SEE
.
~
_ 1 PER
_ E
~ . _ ONCR~ INL~~,Ta g_5
. - SPpKANE CO` LT .
STp. 25+ ~ 9 Zp29.75
. GR,p~TE E~
OF V2» OW CPE
40 L.F. .
. ~ s,-o.0°62
7.s2
W _24
.
~
2027.37
~
~ .
, p~ CONCR~.~pE 1
L - PRp\/IDE 4 ~~CURB jN~ .
ApRON p BO~pM
s ; . . / Tp pQN
/
r_ t
~
1~-
1
~
, .
. .
. ,
f--` ,
. . .
~
. . . . _
~ _ ~
Weighted Runoff Coefficient Calculation
.
Project: Riverwalk 7th Addition
Basin: Y IPE Job 96070
Total Area (acres): 1.48 Designer: B. Howard
tmp. Area (acres): 0.90 Date: 8116/96
Grass Area (acres): 0.58 .
Imp. Area "C": 0.90
Grass Area "C": 0.10
(Imp. Area)(Imp. "C")= 0.8100
(Grass Area)(Grass "C")= 0.0580
1.4800 0.8680 _
Weighted "C"= 0.8680
0.59
1.4800
R;>:BOWSTRING METHOD PROJECT; Riverwalk 7th Addition
PEAK FLOW AL I N PROJECT; Riverwalk 7ih Addition ~r:•;::;::A~• ~~,v::~
`•"`~DETENTION BASIN DESIGN BASIN: Y
BASIN: Y ~~♦,,~,4~,,
\}'}}t.Y.L~LIYY.~Vl.N};,:~.10-Year Design Storm DESIGNER: S. Murphy
Tot. Area 1.48 Acres ~y:•y;tiS~}y~:~~(;5ti'5•.L` DATE♦ n/~ V! 1 VI
\Nti'•411~15VLL'~411~\ 11/^~1I96
Imp, Area 39169 SF
5~}Y'S' 5'•••
c = 0.59 ,
it:xx~:Ki<:iz. `
"`''"~X~`~~'•~~r~''Time Increment min 5 YMW •..•.41
`L}•:~~41Y:A1L41V.~1~
1 Y'.
CASE 1 Time of Conc. (min) 14.16
~4>.«ryt ~.~Outilow(cfs) 1
30 ft. Overland Flow ~~•',Z~,~.vxy"{ixx~Design Year Flaw 10
Area (acres) 1.48
Ct = 0.15 Impervious Area (sq ft) 39169
% %
L 30 ft. 'C Factor 0.59
= ,;<•K.
..~a.a.v.~ t
~L45ti}
n = 0.02 ~ :.t•: ~'208' Vofume Provided
Y.5\'.•h4 l
41N1'.51t4.'.4::•. \l ll\ 1
S= 0.010 '••~;~;,,,,?;~~ti,~; Area C 0.873
~.•,,~,~,'.~i;:t'
~;?:;at r";.•:,,>.
Tc = 0.38 min., by Equation 3-2 of Guidelines
' i1 ~"1:;;'•'yt'Z~~~< Time Time Ina Intens. Q Devel. Vol.in Vol.Out Stora9e
1430 ft. Swale flow (min) (sec) (iNhr) (cfs) (cu R) (cu ft) (cu rt)
Z1 = 50.0 For Z2 14.16 849 1.84 1.61 1828 849 978
Z2 = 1 Type B =1.0
~ x}x.}«}}+
n= 0,016 Rolled = 3.5 5 300 3.18 2.78 1116 300 816
S= 0.008 Swale=3.0 ??:;<:::>:<?:s:•:::~<;;;;~:LLV.:t.Vti1
600 973
10 600 2.24 1.96 173
• "`'`;~~;;~i~~~~`~~:~:~ 15 900 1.77 1.55 1837 900 937
~ •~~~.~:;}};~{i~ti~k
d = 0.191 ft.
~ 20 1200 1.45 1.27 1885 1204 685
25 1500 1.21 1.06 1890 1500 390
\ ~4~\5•.~5~.~1`.`L5Y1'\
A R Q Tc Tc total I Qc 30 1800 1.04 0.91 1897 1800 97
1'ti'l~'''i,•,±+45µ~~~,
`?.•:~~'~;r:~~;: 35 2100 0.91 0,79 1898 2100 -202
';xa~~,~«.~,.;,,;.::
0.93 0.09 1.61 13.77 14.16 1.84 1.61 40 2400 0,82 0,72 1925 2400 475
45 2700 0.74 0.65 1931 2700 -769
445uv:~\Y~YN~~:iVA
`\•.v:.1':.~
x~w:.ti•.+v.t
Qpeak for Case 1= 1.61 cfs 50 3000 0.68 0.59 1953 3000 -1047
yi:4 'iti~u:ti~•:i1LM••{\
;;;s'~. 55 3300 0.64 0.56 2006 3300 -1294
~..5v.5v.5v.x.x~xtix
60 3600 0.61 0.53 2071 3600 '1529
'~kv.~tii•.y::::xi{~~
CASE 2 . •"K~"""; 65 3900 0.60 0.52 2195 3900 -1705
x;.~;`;~~K.~,
~
;:`:~';;;;:::??:?<;.'•i~;~ 70 4200 0.58 0.51 2273 4200 -1927
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.49 2342 4500 -2158
peak flow =.90(3.18)(Imp. Area) = 2,57 cfs t)
y pl/ ~ 4800 Q.CJJ ' Q.'AIV c y~~~ LJJJ ,~Qry `IV'0 '2`} ,YJ
~AC
85 5100 0.52 0.45 2447 5100 -2653
tLL~ \~v.LiiY•~.\E ~p~
4::~.`\`.•`.tK`~?y`;•'.;?;1.
~L}•.vnt:. i•.~ 90 ~J'IVV O.JV O.'A1Y Z`fG7'f JYW '2916
}}tSi`?:.:?is•♦.~
LV :'::1.~1NVt
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.43 2562 5700 -3138
;;~~~~µ<?x••:::a;~i~::~W.5~1tii~i5}\Y.1~
2,57 cfs 100 6000 0.48 0,42 2636 6000 -3364
'.1ti}1V.51~\ti11Vy~.5\~K~~~`
1ti'•.~L{5~:~1:~11151~5•:1
1'. 5Y.y)1'~.NllN4\tiNVt,
111N51NLKi1Y.LtiLtiY ti11i'.vtiLS\Y\\~\V.54\+1\~titi~
DRAINAGE POND CALCULATIONS
K5'h
k:?::~~:'",::v:•~~'~~:Y Required'208' Storage Volume
Impenrious Area x.5 in ! 12 in/ft 1632 cu ft
v~%%% Kµ„.. x:;
' ;
208' Storage Volume Provided cu ft
Axx.x+1
~f{~}.;•yv Ci~x•.ti•.x~.~
1 5'h1'.\5V.1\•. lL~N.•.`
i4•.S\1kv.\~N1~4Y lY
1µY.1N1 . y
K~Sti YM1N4~1\' 1~ :5•.:11
REQUIREMENTS -10 YEAR DESIGN STORM
\•.1Y.~~ltY.
aximum torage equi owstnng 978 cu ft
``tx41`\\`451N \~titi~
~yl•.11{'.~yll'.h`.N': Y'hl
;:a.,.;;.:,,,<a;;~.ii~,:
Number and TYPe of 0MweIls Required 0 Sin9le
'X4tiiLtii~l~+tlL14~~M1~~•.\•
••N~N~'.N~ `hllv 11ti~
1 Double
i~ :a#:•+i3?ss::?. iii+c
Pipe Flow Calculation CB 3 to DW Basin Y
Flow 1.400 cfs Out IE 2028.65
Diameter 1.50 ft In IE 2028.85
Slope 0.0100 ft/ft
n 0.0240
L 20.00 ft d/dia A R Q V
Depth of fl ow,d 1.35 ft 0.90 1.6605 0.6741 7.93 4.77
Flowing Full 1.50 ft 1.00 1.7672 0.5625 7.48 4.23
Critical Depth 0.435 ft 0.29 0.4253 0.3740 1.40 3.29
Normal Depth 0.495 ft 0.33 0.5085 0.4158 1.40 2.75
HWc 0.687 ft
HWn 0.672 ft OUTLET CONTROL
HWp ft
Circular Channel Analysis & Design
Solved with Manning's Equation
Open Channel - Uniform flow
Worksheet Name:
Comment : Riverwalk 7th Addition , . , . ,
Solve For Actual Depth
Given Input Data:
Diameter.......... 1.50 ft
Slope 0.0100 ft/ft
Manning's n....... 0.024
Discharge......... 2.57 cfs
Computed Results:
Depth 0.71 ft
Velocity.......... 3.14 fps
Flow Area......... 0.82 sf
Critical Depth.... 0.61 ft
Critical Slope.... 0.0172 ft/ft .
Percent Full...... 47.13 0
Full Capacity..... 5.69 cfs
QMAX @.94D........ 6.12 cfs
Froude Number..... 0.75 (flow is Subcritical)
Open Channel Flow Module, Version 3.41 (c) 1991
Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708
Backwater Calculation Sheet - Riverwalk lth Addn.
Pipe Segment C133 - DW
1 Q 2.57
2 Length 20.00
3 Pipe S¢e 1.50
4 n 0.024
5 Outiet EI. 2028,65
6 Inlet EI. 2028.85
Slope 0.0100
7 Barrel Area 1.77
8 Barrel Vel. 1.45 ;
9 Vel. Head 0.03
10 TW EI. 2029.62 ,
11 Frict.loss 0.04
12 Entr. HGL EI. 2029.66
13 Entr. Head loss 0.03
14 Exit Head Loss 0.03
15 Outlet Ctrl. EI. 2029.72
Inlet Ctrl. HW 0.999
16 Inlet Ctrl. EI. 2029.85
17 Appr. Vel. Head 0,00 .
18 Bend Head Loss 0.00
Junct. HL Coeff. 0,00
19 Junct. Head Loss 0.00
20 HW Elev. 2029.85
Grate EI. 2032.85
Freeboard 3.00
RECEIVED
SEP 19 1996
Table, No. 2- Pond and 208 Basin Summar,y
~ . . .
. -
s :•.ti:::•:.~•.~:..:::::::::.~::::::::::::::::::~::::•';~.:::::i:=i:•i:;:::~:::::;•::::::::::::•::• ~
INE
ER
. . ~ ~ :
:Y}.V. .1..... ...l.~ ::•N::::t.. 1 •••.r.............. . ;N
.l:
..:....:..:...........:.~::..i'' .•.~:.~.ti:::S.:~.• ...:.n• v.~:.~::::::;~:.................~:.:~..
...........h...... :•..i•~.... :v' '"'v: :•v.:~:::: ~ . .-.......v:::::{.}•.;w::::: .......-0~.;.... .n..... f.
; .v.,
. .......'""••'rv
• ....x........... . , :r......... • w: v. . . . . ::}'r::4: •i}
~ :•.w:::: v: . rr.:: ::v.
~ . ' - •
. : . ~ : . . . ~
v . v: • r . x, . . :
. ~ 1t . ...L r.ti . . . . : - . . . . . . . ~
::.::.,t:,~~:~.: • .
. ti.; . • : • •~fi.. . - ~8~~•`7 • •dt~iE~~::~~1 : . - .....':~::::=:::::;:':.::.:r
:.~i f~.... . . . . . . . . .
: ~r~
.
~ . - -
-..Y.., . .::.:.v.. . . .vfr.. . :•r:~::<;•:::•::~::-::~::•:~::•::::•.
•.•...ti • . • J....... 1............ f . • . • ~ . }M1:ti . . . ~x1ll.::..: ~ ~..•:.•:.ti .....}J.tif. ~t.•::: • ..4
' 1........ .:::.1t....
. . ........ti..........~~... . . l.~~~~~~.............:. .:.ti : ~•:.':.':..J.'.'iti:ii:.V:_::::::•.:Y.~..
....................•..1... . iii...~::::....::. ~1i.i~:.~ . . }l.'i.•ii •
. .•......::::1:1:. .....1..........:::ll•.VJ.VlY•
. ~
" .ti.~ ........t............... ~....1l.~::.. .
. ....~.~~~~.~.ti.. .......ti•.........• •~i~i'i~ ._....Y tiW::.::•~:•=:•:•:'~•::
........YL • ~ ~ ~ .
: : ' . • . •.:V
• • {1}.:•: . :V : ~ • l .f
. l~ ~y
Y. ' • . • • . . ! \ ~ ......ti.. • ' 'l j.
• ~ r . . . . . • ' ~i':. : ~}ti . ~ ti . ftilt
..::::r:::::: r...:•::::• . ;r>.::... : , ::;c:~:t::.: ~
~
. r.:::~ . r:..;..
. . '~'''t....... . . . •~1V4~. .~r~• ~ ::;r.; V~,~.;' ~ .r;;::•::
. . ~ ~ ::r,~•~.....
~t
• :.:.......~4?~~ .
: : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : : : : : . . . . .
~r . . . r~:~.. . . . :•:::f:•.:r.. •
...r.. v~ ............:;.f ......ti..... . . .v.... . •.x:x:•:;.
~ : ~ : • . v ~r . . . . . . . . r..
. •
.ti.ti... . r . ...r:::•::~ . : . . . .
.
. f... ~ •
v:: ; •
• . . . •
•:~r
tY~~f~ C .:.:::::.:...:~•:~@ ~d i~:: S:.:::: :::•::::~!'~~i~i~::~~~:::::::~:
~ M:._:::: . . ~ .
;~:•s.;•~:.z;;::::; :::::::::::::r:~:•:.~:: . . .
A , A , 203 406 426 1B
B B 203 406 426 IB
C C 177 354 375 1B
D D 209 418 426 1B
E E 87 174 180 1B
F F 271 542 798 1B
G G 87 174 180 1B
H H 290 580 691 1B
I I 396 792 1097 1B
J J 421 844 990 1B
K K 206 412 419 1B
L L 255 510 676 1B
M M 222 444 470 1B
N N 242 486 500 1B
p O 290 580 600 1B
p P 99 198 210 1B
Q Q 130 260 275 1B
R1 RT - - - -
S S 194 388 400 1B
RT RT 610 1240 1800 1 B
U U 432 864 1132 2B
V V 413 826 1088 1B
W W 118 236 256 lA
X X 67 134 143 lA
Y 1 Y 1 608 1216 2666 1 B
Y2 Y2 802 1604 3460 1 A
Y3 Y3 223 446 713 1 A
Type A is a Spokane Standard Drywell - Single Depth, Capacity 0.3 cfs
- Type B is a Spokane Standard Drywell - Double Depth, Capacity 1.0 cfs
Inlond Pacific Engitieering Con:pcnry D7 Rivenvalk 7111 Addition Plat Drainage Report
M1tiW:.1'::14•i:.:•::::LN
gOWSTRING METHOD PROJECT: Riverwalk 7th Addition
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition fi"~<;~'•"::~~:;";~~';~,~; DETENTION BASIN DESIGN BASIN: Y1
. i::,:~•
BASIN: Y1 10-Year Desi9n Storm DESIGNER: B. Howard
Tat. Area 0.55 Acres
Imp. Area 14592 SF DATE: 9114/96
C~ 0.58
h}{i{tii•~i{iii~>.+i~i~t~:
n.xv.N~vwntv.w::.~
NttS 15
ii?';>Time Increment I /
min1 5
l}{u145•.4NLL'hN1 1
CASE 1 Tme of Conc. (min) 5.00
===_e_= F;'."•:;~'yi; DUffla1N (CfS) ~
HSNh:~~
30 ft. Ovetland Flow Design Year Flow 10
ti<.~,tt;:,.;
%,Area (acres) 0.55
4 hVL\ 1\ l~ 'ti\
Ct = 0.15 Impervious Area (sq ft) 14592
L = 30 ft, s• ,~;~;•<•~~r,:;...;, '
C' Factor 0.58
n = 0.40 Volume Provided
S= 0.020 C 0.319
~:~'•i;~<::<~;;:;;~:.ti:':;
.~,,~ti; n,.•.c,.,
Tc = 2.15 min., by Equation 3-2 of Guidelines
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
87 n. Gutter flow
(min) (sec) (iNhr) (cfs) (cu ft) (cu ft) (cu ft)
~jf%•'•:?;;.`;.'.;,;;:;iy;'v:
Z1 = 50.0 For Z2 5.00 300 3.18 1.01 408 300 108
Z2 = 1 Type B =1.0 ~,~;".';;;a.~•<'•~;i~i~~~'
n= 0.016 Rolled = 3.5 5 300 3,18 1.01 408 300 108
k~i•} i~:'~ ;tt2~v$r?^$'r'.
: ~ : : . : ~ :
S= 0.008 10 600 2.24 0,71 502 600 -98
N:V.•: \•.\'i`:•.N'.11:?L~
~,;.L:•, .•.ti•:. ti.,t,
15 900 1.77 0.56 566 900 -334
c:':;:::<• . ...~,7
d= 0.161 ft. 20 1200 1.45 0.46 602 1200 -598
25 1500 1.21 0.39 618 1500 -882
A R Q Tc Tc total I Qc 30 1800 1.04 0.33 631 1840 -1169
<:i ~ a•.:.~u•. a,
,..,:::~;~,~„v~~:~::;
35 2100 0.91 0.29 639 2100 -1461
0.66 0,08 1.01 0.94 5.00 3.18 1.01 ~;:'•;«::`<:hi~:~';;"i<<>~~ 40 2400 0.82 0.28 654 2400 -1746
. ;;~~~~~:M<~:~'K~`:•::, 45 2700 0.74 0.24 661 2700 -2039
Qpeak for Case 1= 1.01 cfs 50 3000 ' 0.68 0.22 673 3000 -2327
:4•.N1M1K tlN'A~ti11ti5H
~
~f~ JJVtI ~ Q.VC,~y Q.~ 695 3300 'L ~W/►J
+'.}v: ti:~;i# i'{•:{ii: w
:i~ `Y'x'~',~'•~}A`µi?::;
60 3600 0.61 0.19 720 3600 -2880
;
..1^ .ASE 2 ~;,,~xx:~•~: 65 3900 0.60 0.19 766 3900 -3134
~ 5V.1N1N5tiY.vA
;;,•..'~NN'~'"• 70 4200 0.58 0.19 796 4200 -W4
1'' V L~LSll~K~li•i~i
Case 2 assumes a Time of Concentration less than 5 minutes so that the
75 4500 0.56 0.18 822 4500 -3678
Peak flow =.90 3.18 (ImP. Area) 0.96 cfs
80 4800 0.53 0.11 829 4800 -3971
;,L•.,,,,~,•.,x.::..~
85 5100 0.52 0,17 863 5100 -4237
90 5400 0.50 0,16 878 5400 -4522
' ;i;;;;?;`::t#;:y;
So, the Peak flow for the Basin is the greater of the two flows, 95 5700 0.49 0.16 907 5700 -4793
•.,,.a:,,,; t;
1.01 cfs 100 6000 0.48 0.15 934 6000 -5066
`~'•~;t;: ;t;;~~„~, a,
~1v15411~4' M1~N\v 1.~~
~~vHSN•.5'y~:141~41ti1t•
\iti~+i~tin~i:i>>,yr
%titiN\`\t1 A1.+y:•.l': '
~""~n<:;;~:~•"{~~; 208 DRAINAGE POND CALCULATIONS
Required '208'Storage Volume
Impervious Area x.5 in / 12 iNft 608 cu ft
~ti'44~titi{1'.11L~4'A~V.N1
~ LV1L.{1.{\'.'.'415,'1~1
20g1 Storage Volume Provided cu ft
+~ti\1'1 ~1' NNt iN
~N X 5111W.1'.~tii
. 55N~h4tititi{`•: 1:',::.~v
. 15~V.'✓..N'.111' .Lv
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
}'`.'~~Ny:tititi5ti1ti11ti~•,ti L+
•.+L}~14W.Y`.1'.~N
51 •A4Y11 l~+
, .,v.:,,•. „
+~Maximum Storage Required by Bowstring 108 cu ft
• •ti'Lt.5~`1ti;1\
:~il4t 1151'~\5•.'.1\\1{5i
. ltV.1\N\ }µN\L}1~
~l•.5115t 51N'. nt':~.~ti~
4L11t51~5\Y\ :!•M1•.Ntt
Number and Type of Drywells Required 0 Single
W'1LYhNt 1'hMiLtM
• , 4i2~i}ii:'~ vn~x•.4„
1 Double
~
KLNV.NtX~ • KH
~:~(~•:.h1~.5"}•X1«L{ti
~ BOWSTRING METHOD PROJECT: Riverwalk 7th Addition
PEAI( FL-OW CALCULATION PROJECT: Rivenwalk 7th Addition DETENTION BASIN DESIGN BASIN: Y2
l.l~yh5•:.\\\ LN•.~yl\}•
BASIN: Y2 0-YearDesignStorm DESIGNER: B. Howard
.5'~N~\\1N!l±1\.1ti
Tot. Area 0.72 Acres DATE: 9114196
Imp. Area 19236 SF
C = 0.59 ,:~•.::»,<K;~.,t
. t {•.::.~}.x~
~~{t~t w:: •x•n
Time Increment (min) 5
• CASE 1 Time of Cona (min) 5.00
, ~ .,,•.~,,,,,.:..ti~.
~ 4LV:A»W~..{i•: ti14
oY,l I V 'y1rt~I Vfc J O^{
~~~~r `Y1y~ti~~LtiS{ •.til.V;•AN~ , .V
iC~w:~.~~w: n%.r.4•',•',•5
~•:.4`}v.}•:.}`;~:...~.~.~
30 ft. Overland Flow Design Year Flow 10
LL?X•. .titi'.'.'.}{'•'1J::~1l.~
Area (acres) 0.72
«i;~::~~,•:.,,,•:.;,:.
= 0.15 Impervious Area (sq ft)
19236
1i~2`#; w`;^;'':
L= 30 ft. ~`:.;•:`;»``}~'•:i~~:~~~'C Factor 0.59
15'i yt}.}'ti4tiV.n = 0.02 <,::<:<::;;..~~~~•~~,~2 ,
ag~;X08, Volume Provided
S = 0.020 <;;;~:`::•>.;;>:~~~L~~,Area' C 0.425
~ ~
:
•v~t}~'>.s:•~•.i•r
~.:.iii:: v:::j•:,{•.~.ti. i•
Tc = 0.31 min., by Equation 3-2 of Guidelines
~v.L~v.v.•.~•.v: •.x~'.
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
114 ft. Gutter flow ~yl~•:xL:•:
• 5tixv: rv •.v.txx•.
(min) (sec) (inmr) (cts) (cu ft) (cu ft) (cu ft)
Z1 1 = S VO.O r COr ` 7/ L i;'~~:;:vi'•:::tii Sj~~Q
5ti411'1~1:..: l•J.lY`AX5
55 W!!.5'!f'.NN\Y.l51LY
5.00 300 3.18 1,35 543 90 453
Z2 = 1 Type B =1.0
n = 0.016 Roiled = 3.5 .;.;;;"'r`~<'•':a~:~;:~:~~:;
:~.~v:~.:;<•:,«:, 5 300 3.18 1,35 543 90 453
S= 0,008 ~~::•`:~z''~`~~~5"~:Y:'.:; 10 600 2.24 0.95 668 180 488
~~N~•~.hy45115~y~1L\ ~4L1 L
:.tV .LN ~~KLNU:`L1L
~t'Nll~\ti'~l:l`•
15 900 1.77 0.75 753 270 483
d= 0.I79 Il. Yi}~ti~+tit»"k20 1200 1.45 0.62 802 360 442
,.Lz~•.,,.,,,~~ A~,.,..,
N51i:;`\ti ANy~
'yf" 45L'1•.1•.Y.•,~ 25 1500 1.21 0.51 823 450 373
~ :'~i4~1N5\\Nl\1~~ti {:4
A R ~ Q Tc Tc total ~ Qc ~~~"'~`':.;`..,""••;x~ 34 1800 1.04 0.44 840 540 300
...,:t~ ti, ~i~L`L
35 2100 0.91 0.39 851 630 221
0.82 0.09 1.35 1.15 5.00 3.18 1.35~~~,*:'n'iiiA'%'~,..
t~~~~ 24qp 0.82 0.35 872 720 152
40
45 2700 0,74 0.31 881 810 71
Qpeak for Gase 1= 1.35 cfs 50 3000 . 0.68 0.29 896 900 -4
~ 5L'.VANt~S\V.5•.~ .N1L~
fi55 3300 0,64 0.27 925 990 -65
;~~::~:t;;'•.
~•.•..:;.~~~•1~~;~;?•. 60 3600 0.61 0.26 959 1080 •121
,
CASE 2 65 3900 0,60 0.25 1020 1170 -150
~ :`<:>:~;>:,,:;K~;..•.:.
70 4200 0,58 0,25 1060 1260 -200
•::::.:.}•..4•~•,,::::.:
Case 2 assumes a Time of Concentration Iess than 5 minutes so that the
::v..vnt:w::: •.v
45tlY.l•;
75 4500 0.56 0,24 1095 1350 -255
Pea ow =.90 ,~::..~::~~.~.,.rK~,:.>::.
V.1~:tiV.tititi (3,18)(ImP• Area)= 1.26cfs 84 4800 0.53 0,23 1104 1440 -336
tv.~~. ti vn•:
85 5100 0.52 o.n »as 1530 -381
90 5400 0.50 0.21 1169 1620 -451
i~i~
So, the Peak ilow for the Basin is the greater of the two flows, 95 5700 0.49 0.21 1208 1710 -502
1.35 c(s
100 6000 0.48 0.20 1244 1800 -556
h'.'•t.ti5{•.~.L1 \}M11:~~:•.'J.
\:Y..Y.14LtLY.lYJ.t•.~4'.•.
' LN~.14Yl. 1'
Vf.~'::51111L1LJM1Y.~'.\~C'.;
Vl1: J.1ti4~L A~ :Cti'} 11•(
4n~Wl.l4~.
1L •.Y.~y. LtitiK 4}l Y
\4 i.}1•. ~1~•f.
206' DRAINAGE POND CALCULATIONS
tt• \ti•L~ 11F~14V.y~.4
YL?ti~~~y. ~51•.~ltiltitill•~
~~..>;.;•.;.>",:.~v.,K~..~ Required '208' Storage Volume
Imperoious Area x.5 in 112 iNft 802 cu ft
~ NN1114n14` ~
i\1~L~ .Y5'l.Nl W.~}NY
t.LLtVA'4111~\N•\~.Y\
l5 V. .Y•5`YALlY.1•.~ ~ •.~yy
{44y Y~Ltilti1V;\NtitiV
..•:5.`.'.."..~ 208' Storage Volume Provided cu ft
\5':.l'A'.ri•.vl1ti5K5•.YY.
1'.•..ttl~}{l `\`V~.4ti~{~.Y
~5~~5tititi1514~~`51(l'xNt
`5K5••K}S~yY~nKYf.K'
a.L`t•:;:{;{l1%DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
t ~.~V uuLik•.v7iti
ui v.~n•.~uutxxx
~1H 41\LN\NtnY.•A
•`.,,"„"„'t"y",~,
L'L4 Ma)dmum Storage Required by Bovustring 488 cu ft
4 ~11 \~l~11Y51N+
~'~X 1{N\Y4ANY.•.1
111 '•}i, ~~~14115\NN'
.
.~';;:.::.""•^`x„~::': Number and Type of Drywells Required 1 Single
\`t5•1 y~
0 Double
~
►
r•.K.k.~. . x~,
:.y:y}t. ::iy:~ •.}l.
BOWSTRING METHOD PROJECT: Riverwalk 7th Addition
~iriitii }:;:•{:;:v:ii
PEAK FLOW CALCULATION PROJECT: Riverwalk 71h Addftion
i DETENTION BASIN DESIGN BASIN: Y3
} .
BASIN: Y3 10-Year Design Starm DESIGNER: B. Howard
~
Y>:.•:::,~•.;•::
Tot. Area 0.21 Acres DATE: 9114/96
:r:
Imp. Area 5341 SF
•J:l....hl l:'! 1 ~.L•ti.ti:' i
Ci = 0.56 ;;•`:;3:'':~i:%~:,'•:;$'C::'`:~i:%;
~;;::•>:•;:;.,},.,•:,L•:.~
Increment (min) 5
:•':`,';;:~'xc ;;ti;;;~t
CASE 1 Time of Conc. (min) 5.00
.
_ :;•::<,,;.;:..:;.::~;•::::•~x Outflow (cfs) 0.3
30 ft, Overland Flow Ati'.\;tilti~~:~.1~~•~:{1~;;:; Desi n Year Flow 10
~ Area (acres) 0.21
Ct = 0.15 ~:••.,:.,•.,v. ~
.>~::;:~.>~:,4.~ ~ Impennous Area (sq ft) 5341
~+'tii•:L; ~iti;:~v:• ~;i+iii~ CC
= JV Il k~iii2•~~
L ii~~/' Factor 0.56
n = 0.02 '208' Volume Provided
x vnsv:
S - 0.010 Ri:.'`•i`it"~}:•'.k:`:,t>.i"a(P.a ~ Ci 0.118 % n.;.•..yt1•'r'v:.ti}tv.v: ~
ik LyyL{1L~ )l~
~:•~4NtiL5K'ti.::.:
Tc = 0.38 min., by Equation 3-2 of Guidelines
Lv.~ti•1l..~:.1ti11
ti . •
Time Time Inc. Intens. Q Oevel. Vol.ln Vol.Out Storage
'~`2•''Ys:'<i:::?}}\
58 ft. Gutter 8ow (min) (ssc) (inlhr) (cfs) (cu ft) (cu ft) (cu ft) ,
r:.~::: k v~:
'++~;~:j;'?:;•''~}~`.{::`:t'i~~~~~~~~~~ ~ ~
Z1 = 50.0 ForZ2 5.00 300 3.18 0.37 150 90 60
' 1Y: SV.vW:: f:
yM1{5 .
Z2 = 1 Type B=1.0
•:.'!'.\!ll l14'}J.L•!':l.l~
n= 0.016 Rolled = 3.5 5 300 3.18 0.37 150 90 60
...L'•1':.LV:.~•~~
llt:ti :1'.L•:'J~Stlltti'.~i.~
S - 0.008 A•.~.•..:::•,::,:•:.44.::.:.1
~>.~•:s~:~::~::;~•~;?;;>;:;;; 10 600 2.24 0.28 185 180 5
~~•h
15 900 1.77 0.21 209 270 -61
1LyV.y~•}.ti~4Y•:N
d= 0.110 ft. 20 1200 1.45 0.17 222 360 -138
htiLM1i4•::'.•J'.Nti{ VNf:;:
~~~\1~:.:~:'.: 'l.Nl:l.•:':..~
~•:.>:.$:r;;~:: 25 1500 1.21 0.14 228 450 -222
A R Q Tc Tc total I Qc ::<..<v.
30 1800 1.04 0.12 233 540 -307
ceccc=___ _______=e ==e====c= c=c===_=_ =e====e== __=====e= c======c= : ' \'C ~L~::~•:.~:"v;`? 35 2100 0.91 0.11 236 630 '394
A7 { •,•~"w~`{~'~.'~.~':•'s::~3:::•. ,
0.31 0,05 0.37 0.81 5.00 3.18 O. VI ~},L~Sx~iM1'•.}tiC~;;:;;?:,`•~:; 40 2400 0.82 0.10 241 720 479
45 2700 0.74 0.09 244 -810 -566
Qpeak for Case 1= 0.37 cfs
50 3000 ~ 0.68 0.08 248 940 -652
.
ti<:>::;;•. ~
55 3300 0.64 0.08 256 990 -734
~:<:z;~.~;:~»•:•;
.;~:.,~K..~.:::
::;i;;t~~;~ :.;•:;;;:tt:
60 3600 0.61 0A7 266 1080 -814
. .~•.::.,•.t,•:.,•.,
• ~;~;;~<#~,:::z:~~~.>.<:,;;
.
'GASE 2 65 3900 0.60 0.07 282 1170 -888
.
70 4200 0.58 0.07 293 1260 -961
Case 2 assumes a Time of Concentration less than 5 minutes so that the 75 4500 0.56 0.07 303 1350 -1047
peak flow =.90(3.18)(Imp. Area) = 0.35 cfs 80 4800 0.53 0,06 306 1440 -1134
:•:..t
85 5100 0.52 0.06 318 1530 -1212
::`'l:.`•':'~:~::`:..; 90 5400 0.50 0.06 324 1620 -1296
<i<ii?~#:::;;~?:::<:::::,`•:;:
So, the Peak flow for the Basin is the 9reater of the two flows, 95 5700 0.49 0.06 334 1710 -1376
• 0.37 cfs , t,
100 6000 0.48 0.06 344 1800 -1456
;
:;;~'ti:<:`~R;'sk;;'t.:•`.'t;:i;
'~;;.;a;:•`'2:s::,...>.t:?:
~•~~V"~~~~•~~~`~":::;208' DRAINAGE POND CALCULATIONS
~.~.Vl.lY: .tv.ti:}i
Required'208' Storage Volume
Impervious Area z.5 in 112 iNft 223 cu ft
~~.ti •,tiv,tit.5
hiitiS~titi•:~;:•itiLi{(i~titi~
ti:•n`:•::.r xx:•..; i
i~::titi•:i•:
.1~iti`! :•.ti11 LV.~S•.'.Y'.•A
ll~L'ti 1L~5NL}~~4•.L'.SN~ 208'Storage Volume Provided cu ft
"::;;?::`•`:;:i:::i;:2~12;
~•:::.;;•:.•:t,v:;ti~.:<~.,
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
.¢;.ti•: v:.xv:.v.tiv.~v.~.
'~v:ti•%yw:: v.vi~ri~5~.
Maximum Storage Required by 8owstring 60 cu ft
Q♦+ 1'. YA \'.N•.~
. }i11 hiH:y:ti~l~ti•:`~`~1'~1
~4htitiLti.\4• L'.1y~ J:i
Number and Type of Drywells Required 1 Single
L,>~ ::••.,,;,x~
• ~ ~'r'~`::::`~':'"'~ 0 Oouble
►
RECEIVED
_ SEP 19 1996
Table No. 2 - Pond and 208 Basin Summary
.
NEFR
. ~ ~
, .
. . .
.
. . . .
:{-i:
:rf:
. . .::.r.~•......ti~. rj;:
. : . : . . . . . : -:.:;:.,r.. ~ r.
. ...ti - . . ~ . . Y}... .xx... . . . : . • • :.ti•.:.:'r'~?$i:
!Z.. ..:v.
. . . . . . . . ti . . . . w. . . . . }?'r.,'t:5; • • . ' . .
...::::.ti • • ::.'tiv....,::. ~ y"• ".v w:: ~ • ~v~j . . . . . r}{:•.'•.•i:::: r:~i^;Y: . . .
~ti •'?J•:::.V'.V.:.~.;'
~ : ;.}•.}•.:,~:,r•:: :.v.: ~ r.~.r r~::::: ~ . r... ~ :w:. ' '::.{4. . . . .
vC,, . ' ~ '~:{si . .~~:.~3~.~..5.~{.~L
{r ~
.~.::.r.......
t::.:. r~.~::::::::.~: :.::.~:::...R . ~
.1........ . ~......fh...._...•,... .
. ...ti.....v:.:::.~{•h................... .
. . ....:.:..J.'i:..
{ J ' " ' . . . - i ~J.~ . ..i: i: ti.`yf _
...1..:•:.
, ♦ . _ _ _ . r.......... . ; . , h.. ...:'4........ . Aw:. . • : 5..: }.•.;i• - i{R~-
. : ~ . :
. "'....ti.ti..._ . .a. ...r... . 5?`...........v.v.~. '
. . . . i
.
: ....1. h . - . _ . . . . ~ ~•i'i'r ~'il,.•.
..........ti. x ? . rv......... ...~..y
,
. . . . . w:
.ti . ...1 . . . .M1{.... . . :::~f .~.~::.~fflfN
. ,k~......... . ...d . . .y~.
. , . . ~ . . ; • • ,a-~ ;~fx~r:::~:~
. • .......~t~. .~r... . .ti. ~A_. . : ..ts::.
- .y}~ .
- ~ . • . . - • -f,. . . . • :r•r:::.:•:
• .
. . _ ~ ~
. ' r:::-~~~{~C ;}i:}t:{•. :y~~fi~~Tf~1:;?.j•~~~~
. :~i.%:::..~ L
:.'~.k~.1• .'r, .~.Y T ~ T.'f ti.l' ~J :.S'.L1lJ::! .ti.'L5' y:...~
'ii:.:t•: :.1'.:..::...'}. . .:I:::.'..•l::':•:•.' ~
. ~.t►~~<::~ ~::r: r: •r:: . -Nr::: ~ ~ . X::::.:::•:
t~......... ~ .
. . . ~ : . . . ~ ~ .
•
. ~ ..,r r...:.
. . . . • • , ~ , r.~•... • e 3tt~l;.~t~::.:
. . . ~ . : . .
~ ~ ~ .
. . :r~ , . ~ ,;c~~~~:::::::.>::::: . ti . .
...ti . ~ . • ~ • . . , f ..ti... v3:.... .
.......r titi•:: ti........... .
.....,•:::::::::;;r , ::•.~e~t~~~i..:~C~;:::: ~e4!c~i't~
: : : : : . . . . . . . . . . . . . . . . : . - - . . : ~ : : : . . . . . . . . . . . . . .
.
p p 203 406 426 1B
B g 203 406 426 1B
C C 177 354 375 1B
D D 209 418 426 1B
E E 87 174 180 , 1 B
F F 271 542 798 1B
G G 87 174 180 1 B
H H 290 580 691 1B
I I 396 792 1097 1B
J J 421 844 990 1B
I{ I{ 206 412 419 1B
L L 255 510 676 1B
M M 222 444 470 1B
N N 242 486 500 1B
' p p 290 580 600 1B
p p 99 198 210 1B
Q Q 130 260 275 1B
Rl RT -
S S 194 388 400 1B
RT RT 610 1240 1840 1B
U U 432 864 1132 2B
V v 413 826 1088 1B
W W 118 236 256 lA
x 67 134 143 lA
Y 1 Y 1 608 1216 2666 1 B
Y2 Y2 802 1604 3460 lA
~ Y3 Y3 223 446 713 lA
, , .
Type A is a Spokane Standard Drywell - Single Depth, Capacity 0.3 cfs
- Type B is a Spokane Standard Drywell - Double Depth, Capacity 1 .0 cfs
hlland Paciftc Engineeri»g Conrparry D7 Rivenvalk 7th Additioll Plat Drainage Report
BOWSTRING METHOD PROJECT: Riverwalk 7th Addition
'^,'•n:.`.:;>..•:wc., ~.~i:k:;
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition DETENTION BASIN DESIGN BASIN: Yt
BASIN: Y1 <<';10-Year Desi n Storm DESIGNER: B. Howard
Tot. Area 0.55 Acres ~~9
• ~,~«.~,•.,..,,..xa
~~<•~^hi;s:~;,::•<.:;:.~; DATE: 9114/96
Imp. Area 14592 SF
M1NaNti4titit~){i{5' µxll:t
Ci ~ 0.58
Time Increment (min) 5
CASE 1 Time of Conc. (mfn) 5.00
~~~t;t:•• '
~~`i•,
Outflow (CfS) 1
k~.µ2:?'?~'•" v:.~n:
, 30 ft. Overland Flow i9 r Flow 10
~,~~:'';~'~Aa (acres
4ttt~:t~hiK, wL.Y~SV•; l ) 0.55
0.15 w•v.«;;~~.. ~
Ct =
im prvious Area (sq ft) 14592
v.~ty.t•.j.~5 . 1"'
L= 30 ft. ~
•.~;,,x C Factor 0.58
~ ~
n = 0.40 ~ ~`$N'208' Volume Provided
1•5~~111L\t15 Y.5':~Lll,
S = 0.020
, Area*C 0.319
ti•r L tiv~1~~w
u i•.5 f
' tii4' ti~~•nvnti k''
TCi
2.15 min., by Equation 3-2 oi Guidelines ~
: R•.~v: KiXh~f tiY.hh•.K~
1.544YA~,
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
87 ft. Gutter flow
(min) (sec) (iNhr) (cts) (cu R) (cu ft) (cu ft)
• ~~SY:~i:C:+`iN;~~~~~~~~~
.•:::1~{~{ti~~}..'.4'•:4•.•:1•.1
Z1 = 50.0 For Z2
5.00 300 3.18 1,01 408 300 108
7-2 = 1 Type B =1.0 ~~?::;;i::,:,;;•;m,<::<~;
n = 0.016 Rolled = 3.5
,•:>'~;?~,,:s>:::<;;A;; 5 300 3.16 1,01 408 300 108
S = 0.008
10 640 2.24 0.71 502 600 -98
ii5}•v:.x•.:; •.~~~•.5:•:::~
•.5ti~5ti~5•.~Lil:::~
15 900 1.77 0.56 566 900 -334
. y~,. } . :1 . .
d= 0.161 ft. 20 1200 1.45 0.46 602 1200 -598
':~f.•,~:.'. :i~'.54~{.vi~
. .N.~ 1.
.~.:.:ti:x•v:.x~:•.h~
v:::::.v.~•.in.x~
25 1500 1.21 0.39 618 1500 -882
A R Q Tc Tc total I Qc 30 1800 1.04 0.33 631 1800 -11 fi9
35 2100 0.91 0.29 639 2100 -1461
,>4 • ;w<..;
0,66 ------0.08 1,01 ------0.94 5.00 ------3.18 1.01 40 2400 0.82 0.26 654 2400 -1746
h2?``i•'>;~1 i?2;•.~?:;::
~ 45 2700 0.74 0.24 661 2704 -2039
Qpeak for Case 1= 1.01 cfs
;~•~~;;;>.::.;::<::<;;~~; 50 3000 0.68 0.22 673 3400 -2327
•
•••51tiY5':{N::i
55 3300 0.64 0.20 695 3300 -2605
L+LSVrnx•..•.
" }sx•.x•.v;:'
.r;5{L+`~}{~ n
.
,:;;,:,}~,~•~:;.;;i 60 3640 0.61 0.19 720 3600 '2880
i{{titi'itx•.v: :i
CASE 2 „~~v.:.~.~,
~i;::~i;<,;~;z;,:;t•:.~ 65 3900 0.60 0.19 766 3900 -3134
70 4200 0,58 0.19 796 4200 -3404
Case 2 assumes a Time of Concentration less than 5 minutes so that the ^`'~`~;~•.~~•:.~:.k ;:<••<~
75 4500 0.56 0.18 822 4500 -3678
peak flow =.90(3.18)(Imp. Area) = 0.96 cfs 80 4800 0.53 0.17 829 4800 -3971
:VlAlSllt~ti}••,{.'titiy~~
.l.. ~SV.......
~ i i.~.{~ \'i '..'.':•l titi:t~:~' \
85 5100 0.52 0.17 863 5100 -4237
.;;}~.,#;~;4..~,?.•x~ :'i
`•;~:,~,•':`;;"::`::;::;r 90 5400 0.50 0.16 878 5400 -4522
So, the Peak flow for the Basin is the 9reater of the two flows
'\ti.~,..c,.::•, x;K ~
i ~95 5700 0.49 0.16 907 5700 -4793
1.01 CfS t~:;~,,2,:.<<,•.~.ti;~:,,~C2~
• • ;,•.,~tL,}
1". 100 6000 0,48 0.15 934 6000 -5066
.S~y: ~~?J••\ti 15~•Ni
'Y:5'::\'J.~~:.~{1•M~'A}~
•Y.1'.1~Y.1..5tNtltv:. ~11
i.L1'.NN'h4♦♦♦L'.Y! ::V.411
:1•.1V~1`!.\SVLYJ'•tiN1
1Nn ~{L'.\l•.••:.N
i .
208' DRAINAGE POND CALCULATIONS
y•.,•,:::..
Required'208' Storage Valume
= Imperoious Area x.5 in / 12 iNft 608 cu ft
. <•>~•>,:::,~:<:»> :i;:
;;i;"•`.•:i„i
206' Storage Volume Provided cu ft
:?•'•;`;;~'''':i
;;:.:;•;:~:w,; x:::;:.
;i:t' K..•.~:;`
DRYWELL REQUIREMENTS -10 YEAR DESIGN STORM
..•~..•.,•.,t•~,£:;.;;'
~:~,t ;;~s,;.~• Maximum Storage Required by Bowstring 108 cu ft
! 4}~}51~~5LL
' ti,:htiti~5t~titii5h~•. LiY: i
~ ;2;~,:`::.~2
; ,2,.,x.t:::,
Number and Type of Drywells Required 0 Single
1 Double
►
tiN'.#V.titiilti•.':'•:1LyV
BOWSTRING METHOD PROJECT: Riverwalk 7th Addition
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition :•''"'".`:`}'~""'`"'.DETENTION BASIN DESIGN
BASIN: Y2
BASIN: Y2
K~v`~~•~'•~~~~
1aYear Design Storm
DESIGNER; B. Howard
Tot.Area 0.72 Acres y}1~~Y.5V:.•.•.•.YJSV•:~~
DATE: 9114196
Imp. Area 19236 SF ~ ~~~a~:~.;tir.:;><:~>.•}• ~
V1 hSLlt}t45.`5tht`W.ti~
C(~ > tux
~ .JJ k~
C O vk,sti~
``~~~~~~~~~~'•~~~Y~~~`~k~Time Increment (min)
J
''~~>ti~~Ciiii~~;`i~
CASE 1 Time of Conc. (min) 5.00
Outflow (Cfs) 0.3
• 30 ft. Overland Flow .;".:,..,~:%?;~,"~.;..:`,,.<f? Design Year Flow 10
~:.:::~•~.;~"~,.:;.,,y ~ ) 0.72
Area acres
Ct = 0,15 ~,,,Impervious Area (sq ft) 19236
~11•.'.:~'.~y'.:~~.~Ky. k
...ti
L = 30 ft. «
..,,;~ivL{t::~"Y:.~.:,::::. ,C' Factor 0.59
~
n = 0,02 ~;ri;i a:''208' Volume Provided
S= 0.020 Area' C 0.425
t•.ti.}'.•!}.~;:\5 hti~LY:1i:~
~t: V•\'.1`.11}\'..4•At~\
Y5•:'~Vy~11X5Y..~•!.•f.
NS♦yN1'.SLV..Y.
tV.tii.lltil~ }1~+ ~1}\'I .1~•~
l~titilti54~' ;r¢,":5~ 51•.•.~ V
Tc = 0,31 min., by Equation 3-2 of Guidelines
`•.,v.::•; ti~•: y...~
Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage
~ t <•:; ~ • •
114 ft. Gutter flow ~•r
~ ,,,a tlt•..,,,.,,,•.~,~.:,
(min) (sQC) (iNhr) (cfs)
t.~.;•,
(cu ft) (cu ft) (cu ft)
Ytiw .~~t:jX;~'<tt+••
v.x }ti~i•~_~~__~~~ ~
NK~•.•t•.•:l{ ) tiLV•A~. ~
~LL«}~'~~Altiti{t~ }Ati?
Z1 = 50.0 For Z2 •
5.00 300 3.18 1.35 543 90 453
Z2 = 1 . ~.ti.
Type B =1.0
,:•,,,M::..~.:.~:
n = 0.016 Rolled = 3.5
5 300 3.18 1.35 543 90 453
S = O.~/~~V/~~~{ W ' 'ti4•.LNS.tY:.Y
10 600 2.24 0.95 ssa 1e0 488
15 900 1.77 0,75 753 270 483
.
d= 0.179 ft. 20 1200 1.45 0.62 802 360 442
~"':;;:;;<;;4•~?~ 25 1500 1,21 0.51 823 450 373
A R 4 Tc Tc total I Qc 30 1804 1.04 0.44 840 540 300
~:'t2;'~:?y':., ~
;?~~;;;:i<ti~1~1~~1~14{A~ 35 2100 0.91 0.39 851 630 221
0.82 0.09 1.35 1.15 5.00 3.18 1.351;x40 2400 0,82 0.35 872 720 152
. ,,;~:en~::,?`~::•;~xt~
;{45 2700 0.74 0.31 881 810 71
peak for Case 1 1.35 cfs . .
• : • . 54 3000 0.68 0.29 896 900 -4
,•.~:.::<.:~•:tt.
;~:<::,•.,~.,;t. „,~::>.:z~:
55 3300 0.64 0.27 925 990 -65
?t{~iti4n~:`i}~i?7'ti.Si•
60 3600 0.61 0.28 959 1080 -121
CASE 2
. . ...d~~;:,.•x~: x.;::,
.,k..... 65 3900 0.60 0.25 1020 1170 -150
~ct.:•>,,;; 70 4200 0,58 0.25 1060 1260 -200
Case 2 assumes a Time oF Concentration less than 5 minutes so that the
•^~:e,::?; 75 4500 0.56 0.24 1095 1350 -255
eak flow =.90 3.18 Im Area -
:;•`•;~k,`'`''~: ;~s:
P ~ P• 1.26 cfs ~•~y~, 80 4800 0.53 0.23 1104 1440 -336
4` • .
~:~'Wy.~M~y\~ ~ Nti~~1~~:~•1 BS 5100 0.52 0.22 1149 1530 -381
\'.V.:tN~.V.K:4•1
90 5400 0.50 0,21 1169 1620 -451
So, the Peak flow for the Basin is the 9reater of the two flows.~i~J•~•"~~"""•
, 95 5700 0.49 0.21 1208 1710 -502
1.35 cfs 100 6000 0.48 0,20 1244 1840 -556
u5 •.~L~~`tl\'.~ x5• ~Y
5~\•:• y`~ \:}K51
tiY:X'~l \5
1 tiY,tNlllLt~11.~\`t1
\1lll' V.LYS\'
Y.4X~ \LNM11N\•:.(4l1
~ 1.s}~ x.~~•:nv
ii Yu+v.
•:.K~ :22' L" }
k~208' DRAINAGE PONO CALCULATIONS
~•~~~~f~~~x~~,~~~>~~..~ Required'208' Storage Volume
VALV.h1N~\1N~\~ `,l}'.LL'
i•~yN~1j\N\L~~N~tiS'.\ f
:~;~•:~:,,;~.~~„~:.4 = Imperoious Area x.5 in 112 iNft 802 cu ft
45\LY \ • t
~ti•.xv.u•~u~ti~nxti~~
208' Storage Volume Provided cu ft
YJ:.t\'.\4•.•:: h' • ~1\N~
tw.t•.xxt~•.tiSK~.~.~~n:>.l
} v.v.v::ni~v.~•x.~~x5
iv, uxx}xx~•.w.y ~
REQUIREMENTS -10 YEAR DESIGN STORM
`iiii`iv"•~x~}+ xt~i\
/~11
t5xv,v,~vnx+u•~x~v 488 VY
~~•..~..~~.:«`;•~^mx~~~ Maximum Stora e Required by Bowstring
~~'yti~•~~45~L \ti~~5•.\4K5~
} 42 ~ 5L4•~LV. '
A'\♦♦l14~ ' V~L.v
\1ti~L~•y l~1lNlV.}y41~tiY~
♦ `•r.~ K~M1tiLti\{}~51y15i1~
>~~~~~..~~•~X~~x~~•: Number and Type of Drywelis Required 1 Single
~ N ~..•.t~H•N11M14'.1~
}{~~x{4:;:::Li?t:i.~~.
M7p~•,\M11)}}}?}}~
~~~~~~~•.::~~•K 0 Double
BOWSTRING METHOD PROJECT: Riverwalk 7th Adddion
PEAK FLOW CALCULATION PROJECT: Riverwalk 7th Addition BASIN DESIGN BASIN: Y3
Jt...lf.45•~45•}.L~~L4'.tt•.t~ Design Storm
ASIN: Y3 1a Y e a r
DESIGNER: B. Howard
u,~..:~:~,:::;;• x`~:
Tot. Area 0.21 Acres DATE: 9114f96
1.5•!.`V•N.NW.tt.1•A5'.•.4'A
~ •.~til•.`.'~:{tii11h~~
mp. rea 5341 SF
•.,::x::::~::.::;..~..,
C = 0.56
r'.~:t::• :1Y.N
T
ime Increment (min) 5
CASE 1 ~ ::v.12
v.»t~x4vn
~~~Time of Conc. (min) 5.00
~t\.~1 •.LA1L\NL\'.'{...N
~1SYl:l\NtiLtitiL'.1tiL$~:~:Outflow (cfs) 0.3
: ~ x x•.5:v y.x xti
30 ft. Overland Flow ~~•`:~N~.~"::::~::~~; Design Year Flow 10
~.•:~•:;~~~.~k.~~.;::~:;:Area (acres) 0.21
..,,,.v.~•.,...~::::.,•:.,
Ct = 0.15
Area (sq ft) 5341
•~ti{:ii+~itv
riii}~,`{v.u•~x+xw
v:
, L= 30 R, ~~..,•,x•.v.,..:,,.t,v.-'CiFactor 0.56
fl:.• ~1~NiL5`.`'Ay\4N
n = 0,02 :~208' Volume Provided
S = 0,010 . "
Area' C 0.118
~:•;:<x~ .,K~::;~;,,.;
~•;,.:;•;Kx.~~•::.•~•
Tc = 0.38 min., by Equation 3-2 of Guidelines •
yr..ti,.•: ;
M1'. }Y.14'.114~•f!'.'.SY.t
•1'l.~
Time Time Inc. Intens. Q Devel. Vol.ln Voi.Out Storage
xtvv::•+~.t tu
58 ft. Gutter flow
(min) (sec) (inlhr) (cfs) (cu ft) (cu ft) (cu ft)
b't't.:<:,..:;'+.,}.:.~:...,
~~,~~..~~•.5~.~
Z1 = 50.0 For Z2 5.00 300 3.18 0.37 150 90 60
~ :•::<•::>.;::.<~<::..
Z2 = 1 Type B =1.0
n= 0,016 Rolled = 3.5 5 300 3.18 0.37 150 90 60
:?:`:':;;i~ti•::::::: <>;<:;u
s= 0.008 10 sao 2.24 0.26 1e5 180 s
:."`"`.:.`•:::.~x: 15 900 1.77 0.21 209 270 -61
r:<•,~;:: . .
d= 0.110 ft. 20 1200 1.45 0.17 222 360 -138
~ai
25 1500 1.21 0.14 ne 450 -Zn
x..
~:.5V.4'.•~~~}~~~~~~•.~<.
.5~~ ..:.ti
A R Q Tc Tctotal I Qc 30 1800 1.04 0.12 233 540 -307
"•h`;..::..
:i~:4.it•:}:}~~xxv.x:•.~
35 2100 0.91 0.11 236 630 -394
A1'.11t.:•t'1N tiNL'::.~
0.31 0.05 0.37 0.81 5.00 3.18 0,37 40 2400 0.82 0.10 241 720 -479
45 2700 0.74 0.09 244 810 -566
Qpeak for Case 1= 0.37 cfs 54 3040 ~ 0.68 0.08 248 900 -652
55 3300 0,64 0.08 256 990 -734
60 3600 0.61 0.07 266 1080 -814
CMSG 2 .5}}:.ti.; i1ti•:{C{if}•~~
65 3900 0.60 0.07 282 1170 -888
:,:t:::•::"~`x;;t;>::;:;;t;
_ 70 4200 0.58 0.07 293 1260 -967
Case 2 assumes a Time of Concentration less than 5 minutes so that the
75 4500 0.56 0.07 303 1350 -1047
peak flow =.90(3.1 S)(Imp, Area) = 0,35 cfs 80 4800 0,53 0.06 306 1440 -1134
.,}}Ltii~:•'::iti~'~iiitii
85 5100 0.52 0.06 318 1534 -1212
90 5400 0.50 0.06 324 1620 -1296
hw.L~u•.G:C•'.{2•;{i}}ti.::'
.v~ti vx.xx.
So, the Peak 8ow for the Basin is the greater of the two flows, ~ r5y,4~`~•,••5••y• , l.~ SS 5700 0.49 0.06 334 1710 -1376
4tiV ~'~•.•.Y.:SL 1~}titill~i
0.31 cfs 100 6000 0.48 0.06 344 1800 -1456
~ :i~i:ii•.~ :•r: : ~}itC>.~
.v.~•1xxv.v. ~ nx~~;titi~
.i.X1Y.LY.V::i •.•.N 1}\
♦ 5••~\'.5♦~V:N.~l.1Lti
.N iNty`AV.1\V.HL
• NVt.N}NN 45
~tllivl4+\•L1ltiY~~`{lN
r.ti..KxL~,v.t:}t}•~xv.{.
DRAINAGE POND CALCULATIONS
• v.~v.~
!.h\15~ W"~{11ti:{Y.NN
: L lY.•.Vl1Al111N\l~
V 4'l.Y: •.5 N
~:?;X;~•~,~•.~..,~~~'~~~ Required'208' Storage Volume
• •.a~„
Impervious Area z.5 in / 12 iNft
t ..,~x•::,{,.>:,~:: 223 cu ft
:•,?>.;;;,,>.tt
x •.uvC{iy.~14511N
~lNNL1Y~ '.,•l.5:'.~N~l~
~ •1~lyY.Yl::.tiVANSl L
' 1t5N•. ~Y.S~•.•::All~
•~,N,.~;,~~, 2081 Storage Volume Provfded cu ft
c~ t,:;~
. ~:..K
:::;;i;;;r•r.,tt~:;~i`c;';
:~.,~•.,:•..t?•.
. iti, ORYWELI REQUIREMENTS -10 YEAR DESIGN STORM
~i~•xt~:,~:;;~t~; ~;<;i
~ :•.,,,,t:•:.
awmum Storage Required by Bowstnng 64 cu ft
,•.,..;•.,<<;
. ::;;~~i;';;;;';;L•''•i~{•'•';
Number and Type of Drywells Required 1 Single
~~~•:..,v.,...,
0 Double
~ . .