25273 PE-1206D SUMMERFIELD EAST
'
I SUMNIERFIELD EAST DEVELOPMENT
KEN TUPPER
,
' SPOKANE, WASHINGTON
(Section 35, T 36N, R44E WM)
1
'
SUMMERFIELD EAST, 4Tff ADDITION, PHASE 1
' RESIDENTIAL SUBDIVISION
' STORM WATER
DESIGN BR[EF
RECEIVED up&W
' OCT 2 5 2001 2 iq oZ
Add~~"~"
' ~ox~ couxrr ~xcur~,
' prepared by
OFFlCIAL PUBLIC DOCUMEM
' . SPOKANE COL'PITY ENGiNEER'S OFFlCE
WYATT ENGINEERING, INC. O R I G I
1220 N. Howard Street PROJECT # ~
Spokane, Washington 99201 SUBM(TTAL # ~
(509) 328-5139 PH RE1'URN TO COUNTY ENGlNEER
t (509) 328-0423 FX
' Original Submittal Date: October 19, 2001
'
[679300\drainage report.wpd] Copy No. I
'
'
'
' DESIGN REPORT
' FOR
SUMMERfIELD EAST, 4T" ADDITION, PHASE 1
' RESIDENTIAL SUBDIVISION
' SPOKANE COUNTY, WASHINGTON
(S1/2, Sec. 35, T36N, R44E, W.M.)
1
~ C B
~Q,oY ' F
. tijQ b ' Q~ 'Z
p ~ 35634
CISTE~ Gt~
~ssf~NALti~ 1
D(PIRES 7/1/ 0 3 ! .
,
' "The design improvements shown in fhis sei of plans and calculations conform fo the applicable
edifions of the Spokane County Sfondards for Road and Sewer Construction and fhe Spokane
Counfy Guidelines for Sformwater Managemenf. All design deviations have been approved by
~ fhe Cify of Spokone. 1 approve these plans for construcfron."
,
'
, WYATT ENGINEERING
' 1220 N. Howard
Spokane, Washington 99201
(509) 328 5139 PH
(509) 328-0423 FX
t
'
'
' Summerfieid East 41 Addition
Phase I Subdivision
, Table of Contents
' Section Paae
1.00 Introduction 1
' 2.00 Drainage Area Summary 1
' 3.00 Summary of Stormwater Calculations 4
4.00 Erosion Control Considerations 6
' 5.00 Summary/Conclusions , 6
' List of Tables
' 3.01 Tabular Summary of Storm water Analysis 5
' List of Anaendices
' Appendix I- Project Location Map
Appendix II - Drainage Area Map
Appendix III - Soils Information
' Appendix N- Rational Method Calculations
Appendix V- Misce(laneous Figures
'
'
1
'
'
02001. Wyatt Engineering (679300) Storm Water Brief
' October 19, 2001
'
'
' Summerfield East 4' Addition
Phase 1 Subdivision
' Basis of Design for Storm Water System ,
' 1.00 Introduction
The intent of this design brief is to determine the peak storm water runoff resulting from the construction
, of Summerfield East 41 Addition, Phase 1 located on the north side of Olympic, including unconstructed
portions of Burns Road and Crown Avenue. The project includes construction of 25 residential lots,
portions of the paved streets Crown Avenue, Bums Road and Queen Street. This improvement project
' includes curb, gutter and sidewalk as well as the necessary storm drainage areas to handle the runoff.
The proposed project will be located in Spokane County, Washington (T26N, R44E WM). (See Appendix
I - Project Location Map).
' The storm drainage system (i.e. type "A" and "B" drywells, grassed percolation areas (GPA) or "208"
swales) will be installed to accommodate the storm water runoff generated by the impervious areas
, created by constructing Crown Avenue, Queen Street and Burns Road. Additional drywells will be
installed to accommodate stormwater runoff from non-impervious surfaces of the lots. (See Appendix II
- Drainage Area Map).
'
2.00 Drainage Area Summary
t The project area consists of ten (10) drainage areas (DA). All drainage areas consist of the pervious lot
acreage and impervious asphalt, curbing, sidewalk, roof and driveway, which comprise the subdivision
' facilities. DA-1 is 6,941 ft2 in size and includes the area south of the Queen Street right of way. DA-2
consists of the area in the soutb half of the Queen Street right of way and is 4,060 ft2 in size. DA-3
consists of the north half of the Queen Street right of way, including some of the adjacent lot, and is 8,355
' ft2 in size. DA-4 consists of the area west of Burns Road, between Crown and Queen and is 25,967 ft2
in size. DA-5 consists of the azea in the south half of Crown Avenue, west of Burns and is 4,706 ft2 in
size. DA-6 is 19,846 ft2 in size and includes the area north of Crown and west of Burns. DA-7 consists
' of the area west of Burns and north of Crown and is 7,612 ft2 in size. DA-8 consists of the area north of -
Crown and east of Burns and is 101,231 ft2 in size. DA-9 consists of the area south of Crown and east
of Burns and is 90,625 ft2 in size. DA-l0 consists of the area east of Burns and south of Crown and is
, 64,568 ft2 in size.
' The slope within each DA generally ranges from approximately 0.4% to 1.4% in the area of construction.
Following is a summary description of each Drainage Basin:
'
'
02001. Wyatt Engineering (679300) Storm Water Brief
' October 19, 2001 Storm-1
1 ,
'
' Summerfield East 41 Addition
Phase 1 Subdivision
~ Basin DA-1:
This basin is 6,941 ft2 in size and includes the area west of Burns Road and South of Queen.
' Flow from this basin will be diverted off the street area via a Type 1 curb opening located on
Burns Road. Based on the equations for capacity of curb opening inlets on page 6-40,
"Guidelines for Stormwater Management," a 2 foot opening is adequate. The flow will be
' directed to swale #1. Swale #1 will have a minimum swale bottom area of-100 ft2 and treatment
volume of 100 ft3. Discharge from this basin will be deposited into one (1) type "A" drywell.
' Basin DA-2:
' This basin is 4,060 ft2 in size and includes the azea in the south half of the Queen Street right of
way. Flow from this basin will be diverted off the parking area via a Type 1 curb opening located
near the west edge of the constructed portion of Queen Street. Based on the equations for
' capacity of curb opening inlets on page 6-40, "Guidelines for Stormwater Management," a 2 foot
opening is adequate. The flow will be directed to the drywell in swale 43 via a catch basin in ,
swale #2. Swale #2 will have a minimum swale bottom area of 86 ft2 and treatment volume of
' 86 ft3. Discharge from this basin will be deposited into the type "B" drywell in basin DA-3.
Basin DA-3:
' This basin is 8,355 ft2 in size and includes the north half of the Queen Street right of way and a
portion of the adjacent lot. Flow from this basin will be diverted offthe road via a Type 1 curb
' opening located near the west edge of the constructed portion of Queen Street. Based on the
equations for capacity of curb opening inlets on page 6-40, "Guidelines for Stormwater
Management," one inlet is adequate. The flow will be directed to swale #3. Swale #3 will have
' a minimum swale bottom area of 121 ft2 and treatment volume of 121 ft3. Discharge from this
basin will be deposited into one (1) type "B" drywell. A type "A" drywell is adequate, but more
flow could be accepted from future phases with a type "B" drywell.
~ Basin DA-4:
' This basin is 25,967 ft2 in size and includes the azea west of Burns Road between Queen and
Crown. Flow from this basin will be diverted offthe parking area via (3) Type 1 curb opening
located on the west side of Burns. Based on the equations for capacity of curb opening inlets on
' page 6-40, "Guidelines for Stormwater Management," two 2 foot openings are adequate. The
flow will be directed to swale #4. Swale #4 will have a minimum swale bottom area of 287 ft2
and treatment volume of 287 ft3. Discharge from this basin will be deposited into one (1) type
' "A" drywell.
1
02001. Wyatt Engineenng (679300) $t0i'm Water Br1ef
' October 19, 2001 Storm-2
1
'
' Summerfield East 41 Addirion
Phase 1 Subdivision
' Basin DA-5:
This basin is 4,706 ft2 in size and includes the south half of Crown west of Bums. Flow from this
' basin will be diverted off the road via a diversion ditch located at the west end of the constructed
pavement for Crown Avenue. The ditch will transfer runoff from the gutter into swale #5. The
flow will be directed to the drywell in swale #6 via a catch basin in swale #5. Swale #5 will , have a minimum swale bottom area of 123 ft2 and treahnent volume of 123 ft3. Discharge from
this basin will be deposited into the type "B" drywell in basin DA-6.
' Basin DA-6:
This basin is 19,846 ft2 in size and includes the area north of Crown Avenue and west of Burns..
' Flow from this basin will be diverted offthe road via a diversion ditch located at the west end of
the constructed pavement of Crown Avenue. The ditch will transfer runoff from the gutter into
swale #6. Swale #6 will have a minimum swale bottom area of 160 ft2 and treatment volume of
' 160 ft3. Discharge from this basin will be deposited into one (1) rype "B" drywell. A type "A"
drywell is adequate, but more flow could be accepted from future phases with a type "B" ,
drywell.
, Basin DA-7:
' This basin is 7,612 ft2 in size and includes the area west of Burns Road and north of Crown.
Flow from this basin will be diverted off the parking area via a Type 1 curb opening located on
Burns. Based on the equations for capacity of curb opening inlets on page 640, "Guidelines for
' Stormwater Management," a 2 foot opening is adequate. The flow will be directed to swale #7.
Swale #7 will have a minimum swale bottom area of 109 ft2 and treatment volume of 109 ft3.
Discharge from this basin will be deposited into one (1) type "B" drywell. A type "A" drywell is
' adequate, but more flow could be accepted from future phases with a type "B" drywell.
Basin DA-8:
' This basin is 101,231 ft2 in size and includes the area north of Crown and east of Bums. Flow
from this basin will be diverted off the road via four (4) Type 1 curb opening located along Crown
' and Burns. Based on the equations for capacity of curb opening inlets on page 6-40, "Guidelines
for Stormwater Management," four inlets are adequate. The flow will be directed to swale #8.
Swale #8 will have a minimum swale bottom area of 996 ft2 and a volume capacity of 996 ft3.
' Discharge from this basin will be deposited into one (1) type "B" drywell.
Basin DA-9:
' This basin is 90,625 ft2 in size and includes the area south of Crown to the east of Bums. Flow
from this basin will be diverted off the road via (3) Type 1 curb opening located on the south side
' of Crown. Based on the equations for capacity of curb opening inlets on page 640, "Guidelines
' C2001. Wyatt Engmeenng (679300) Storm Water Brief
October 19, 2001 Storm-3
1
'
, Summerfield East 41 Addition
Phase 1 Subdivision
' for Stormwater Management," three 2 foot openings are adequate. The flow will be directed to
swale #9. Swale #9 will have a minimum swale bottom area of 958 ft2 and treatment volume of
958 ft3. Dischazge from this basin will be deposited into one (1) type "B" drywell and one (1)
' type "A" drywell.
Basin DA-10:
' This basin is 64,568 ft2 in size and includes the area east Burns to the south of Crown. Flow
from this basin will be diverted off the road via (3) Type 1 curb opening located on the east side
' of Burns. Based on the equations for capacity of curb opening inlets on page 6-40, "Guidelines
for Stormwater Management," three 2 foot openings are adequate. The flow will be directed to
swale #10. Swale #10 will have a minimum swale bottom area of 473 ft2 and treatment volume
' of 473 ft3. Discharge from this basin will be deposited into one (1) type "B" drywell.
Soils in the area consist of Garrison Gravelly Loam (GgA) and Garrison Very Gravelly Loam( GmB), and
' aze shown on the attached SCS soils map (See appendix III - Soils Information) for Spokane County,
Washington. As per the Spokane County Stormwater Guidelines, this soil allows for the use of drywells ,
to dispose of stormwater runoff.
,
3.00 Summary of Stormwater Calculations
, Attached are worksheets (See appendix N- Rational Method Calculations) which determine the peak
storm water runoff for Post-Development conditions for each roadway DA. The defined drainage azeas
' are less than 10 acres in size and were analyzed using the rational method (Q=CIA) to determine the
peak storm water runoff based on a 10 YR design frequency. The time of concentration (Tc) for the
farthest sub-basin (longest Tc) was determined using the method outlined in the "Guidelines for
' Stormwater Management", Spokane County, WA.
For all drainage azeas using the Rational Method, the Intensity-Duration Curve for the Spokane Area was
' used to determine the corresponding intensity (I) for each time of concentration. A weighted runoff •
coefficient (C) is calculated for the Post-Development conditions, using the surface types and areas
within the each drainage area (DA).
' Grassed percolation areas (or "208" swales) will be used for storm water treatment and detention for the
Summerfield Subdivision drainage areas (DA's). Type "A" and/or Type "B" drywells will be installed
, within the grass percolation area (GPA). The drywell rims will be elevated 0.5 feet above the bottom
elevation of the GPA. The intent is to provide storage for the first %z inch of storm water generated from
impervious areas that require treatment. These areas include the road, curbs and driveways.
' The capacity of each type "A" drywell is 0.3 cfs and for each type "B" drywell is 1 cfs in the Garrison
soils as outlined in the Spokane County Guidelines for Storm water Management, Pg 4-15.
,
02001. Wyatt Engmeering (679300) Storm Water Brief
' October 19, 2001 Storm-4
'
'
' - Summerfield East 4' Addihon
Phase 1 Subdivision
' Using the Bowstring Method, the peak runoff is routed through each respective GPA to determine the
Minimum Required Storage Volume. The Minimum Required Storage Volume is then determined and
compared to the Provided Storage Volume by the GPA.
t The Minimum Required Storage Volume consists of both the volume required for treatment (described
above) plus the required detention volume. The detention volume is the difference between the inflow
' and outflow rates. (See Design Calculations). In each DA, the Provided Storage Volume will exceed the
Minimum Required Storage Volume.
' Curb inlets, sidewalk inlets or catch basins will be used to divert storm water from the roadway areas into
the grassed percolation area (or "208" swale). The minimum required length of curb opening is
determined based on the procedure outlined in the Spokane County "Guidelines for Storm water
' Management". For a sump condition, the procedure is based on a full opening of 0.5 feet (or 6 inches) of
a type A curb along with a 2" inlet depression (See Spokane County Standard, B-9 for dimensions) or is
based on,a full opening of 4" in the case of a Type 2 sidewalk inlet. For a catch basin inlet on a grade,
' figure 15 from the Spokane County "Guidelines for Storm water Management" was used to determine the
amount of flow captured and the amount bypassed to downstream basins. These calculations are ,
included in each basin calculation.
1
3.01 Tabular Summary of Storm water Anulysis
1
Drainage Time of Rainfall Weighted Total Peak Runoff Minimum
' Area, Concentration, Intensity, I Coefficient, Area, A QIoYR Required
DA Tc (min.) (in/hr) C (acres) (cfs) Storage
(CF)
, Post-Development - Evergreen Park and Ride
DA-1 I 0.93 I 3.18 0.72 I 0.16 0.37 I 109
' DA-2 & 3 I 1.40 I 3.18 I 0.62 0.29 I 0.57 I 334 .
DA-4 0.96 3.18 0.61 I 0.60 I 1.15 I 551
' DA-5 & 6 I L29 I 3.18 I 0.58 I 0.56 I 1.04 I 389
DA-7 1.16 I 3.18 I 0.56 I 0.17 I 0.31 I 208
' DA-8 0.39 ~ 3.18 I 0.51 I 2.32 I 3.78 I 1916
DA-9 I 135 I 3.18 I 0.60 I 2.08 I 3.95 I 1648
' DA-10 1.85 I 3.18 I 0.50 I 1.48 I 2 34 908
1
C2001. Wyatt Engmeering,(679300) Storm Water Brief
' October 19, 2001 Storm-5
'
'
t Summerfield East 4' Addrtion
Phase 1 Subdivision
' 4.00 Erosion Control Considerations
, The erosion or sediment control plans are included as part of this project.
The Contractor is responsible for insuring the use of proper erosion control and shall maintain such
' measures throughout construction, until all pertinent landscaping and permanent erosion control measures
(i.e. grassed areas, paved surfaces) have been established. Maintenance shall include daily inspections
and repair of the silt fencing, hay bales, or other. The Contractor will also inspect all erosion control
t measures following each storm water event during construction or until the permanent measures are
established.
' Specific temporary measures which will be used during construction include the installation of silt fences,
hay bale check dams, and construction entrances. The measures will be installed along the down gradient
property lines, parallel with the existing ground contours or perpendicular to the storm water runoff
' direction. The upstream ends of all eYisting culverts will be protected by the installation of hay bales.
Construction entrance will be required in order to clean the tires of trucks and vehicles exiting the .
construction area.
' Periodically, the temporary erosion control measures must be cleaned of debris and siltation. The
contractor shall dispose of the materials so as not to damage any reclaimed areas or create other erosion
' problem areas. Upon direction by Spokane County, Owner or Engineer, the Contractor may also be
required to clean the County roadway of siltation or other debris which may occur along Crown Avenue
or Burns Road at the construction entrances.
'
5.00 Summary/Conclusions
' The storm water runoff generated by post-development conditions of the Summerfield Subdivision project
will be directed to `208' swales sized to handle the first %z inch of stormwater runoff. Discharge from
, these swales will be directed into the subsurface native soils using either type "A" or type "B" drywells. -
The GPAs (or "208" swales) will function as storm water detention areas as well as provide treatment
prior to discharge into type "A" or "B" drywells. ' DA-1 is 0.16 acres in size with 0.11 acres of impervious area. Drainage will be directed to a`208' swale
with a minimum capacity of 109 CF and will be discharged into the subsurface strata via one (1) type "A"
' drywell.
DA-2 and DA-3 are 0.29 acres in size with 0.15 acres of impervious area. Drainage from DA-2 and
' DA-3 will be directed into two `208' swales with a minimum capacity of 334 CF. Discharge from DA-2
will flow into a Catch Basin and then into the Drywell in DA-3. Discharge from DA-3 will flow into the
subsurface strata via one (1) type "B" drywell.
'
02001 Wyatt Engineering (679300) Storm Water Brief
' October 19, 2001 Storm-6
1
'
' Summerfield East 41 Addition
Phase 1 Subdivision
' DA-4 is 0.60 acres in size with 0.31 acres of impervious area. Drainage will be directed to a`208' swale
with a minimum capacity of 551 CF and will be discharged into the subsurface strata via one (1) type "A"
drywell.
' DA-5 and DA-6 are 0.56 acres in size with 0.26 acres of impervious area. Drainage from DA-5 and
DA-6 will be directed into two `208' swales with a minimum capacity of 389 CF. Discharge from DA-5
' will flow into a Catch Basin and then into the Drywell in DA-6. Discharge from DA-6 will flow into the
subsurface strata via one (1) type "B" drywell.
' DA-7 is 0.17 acres in size with 0.08 acres of impervious azea. Drainage will be directed to a`208' swale
with a minimum capacity of 208 CF and will be discharged into the subsurface strata via one (1) type "B"
drywell.
' DA-8 is 232 acres in size with 0.82 acres of impervious area. Drainage will be d'uected to a`208' swale
with a minimum capacity of 1916 CF and will be discharged into the subsurface strata via one (1) type
' "B" drywell.
DA-9 is 2.08 acres in size with 1.03 acres of impervious area. Drainage will be directed to a`208' swale
~ with a minimum capacity of 1648 CF and will be discharged into the subsurface strata via one (1) type
"B" drywell and one (1) type "A" drywell.
, DA-10 is 1.48 acres in size with 0.49 acres of impervious area. Drainage will be directed to a`208'
swale with a minimum capacity of 908 CF and will be discharged into the subsurface strata via one (1)
type "B" drywell.
'
The Contractor(s) will be responsible for the proper installation and maintenance of all temporary erosion
' control measures necessary to protect down gradient areas from siltation. The Contractor shall also
protect against siltation of the drywells and GPAs (or "208" swales) throughout construction.
' A one foot berm will be constructed along the north boundary of the plat to prevent runoff from the north -
from entering the plat. Type "B" drywells will be installed at the east and west ends of the berm to
handle any runoff that accumulates against the berm. These measures are outlined by Spokane County
' as a requirement for the plat.
The bottoms of the swales in the development are constructed parallel to the road curbs and 1.2 feet
' below the top of curb. All swales are less than 1 percent in slope and are considered flat as per the
Spokane County "Guidelines for Stormwater Management." Driveways will be constructed across the
swales when the lots are developed. The area of these driveways has already been subtracted from the
' area of the swales, and the runoff from the driveways calculated for treatment. Driveways will be
constructed across the swales with a low point 6" above bottom of the swale. This will allow areas
between driveways to act as mini GPA's and prevent a single large area of ponding. Overflow from
' these mini GPA's will continue to the drywell location and be discharged to the subsurface.
m2001. Wyatt Engineering (679300) Storm Water Brief
' October 19, 2001 Storm-7
1
~
' Summerficid East 41 Additian
Phase t Subdivisian
1
1
1 1
1 .
APPENDIK I- Praject C,ocatzan Map
1
~
~
1
1
1
~
1
1
~
~
' 02001 Wyatt Engineer'sng (679300) Storm Water Brief
Qctnbcr 19, 2601
'
. . -
p 1
n ~ $'OWafSH
~
~ -
~ ui
~
c ~ y m °a
PfNE S RfNES R!3
E -
~
`n
' MCDonear_p
~
- ~ ❑
~
~EVERGREEN Icy ~ EVERGREEN RI] '
¢
naAMs
~ OD
~ PRDGRESS
~
~ SULIJVAN Stll.LIWAiV RO ~
~
~ . ~•°°9 ~..w.~~m • . ~
n
1 -
' Summerfield East 41 Addirion
Phase 1 Subdivision
'
'
'
1
APPENDIX II- Drainage Area Map
'
'
1 '
'
'
,
1
,
'
1
' 02001. Wyatt Engmeering (679300) StOrm Water Brief
October 19, 2001
'
-,pr"
r rc `~„n
IMPERVI{}US AREA-2,620 SF
TOTAL AREA=7,6.12
OflE FOOT 9~fi'lA
'n
~ 9Efi'
-A
9 GRAPHIG SCALE ~11 flo$~
• 6i. 'w I 4L,~.:..!`_,~i
0 40 AQ IEM)
tZibi It, ~ ' Itl 7S6 d \ r^
~ _ 1~i3 N
.
. ~
d
r ~
_ •V~ ~ ~ ~ ~ y1
14= of Q~ ( QN F'EE"l' )
DAs l inch = Bfl H„ ~
rp~ pn'+ c - c2 cr t ~ ` I 2
IM{~LdSY~VVJ''1~1f~~(,~j~/,G~=J~,OJO Jr - ~ 13,319 if ~ kO7E" TNE rMaERV1[H15 AtiEAS INDfCJrrtu ~
TQTAla'AREA=19,84& ARE T+osE aaEas REouiRF-INc rREAruEkr, ~
a++aa aoft . ~
~LI t"
~ ~
~ C R t
11 ~'N LLJ oa a o~~
~ ~ snr: rt+aeai ~ew~,~ ~ , {~1•~ ~~~q
m --LJ~' ~ ,~~C ~ ~ \ J7 ~ ID,tl~ of ~ V =W7,~M+
~ fMPER4'1O-[lS"APFA=2,9W`SF <a,~~ LL _ ~ Lnr,o D~ °
0 o~
° ~ .F&AC. ARE"4,706 « +aziepW
Ph~4PERVlp~lS AREA=23,910 SF
1 oew tOTAL AREA=101,231 SF
LOT ~
19,773 sf
Ln xU'G ~ \ G lo't 7
106679 M
LDi9
WF 44 ~ `~e fA7~F M I l~ A z
r y ~
v D~A4 11,245 sf 0
a , _ g I LOT „
~ IMPERVfQUS AREi4=6,$$0 Sf 10.4e0 of
~ TOTAL AfaEA=25,967 'z ~7 p+
~ rT ,~r LOT s
146437 of
o - , e rr EYD~m U7
ro Fr swF ,wr~ - - ,a LOT 4 G4 'Q~
z ~
LOT $2 02
IIO,ABQ of E- ~
~ DA3 LOT ,s ~ ~ , , ~ ti ~TN• ~ H ~ry
!
~ ,MPERUIaUs AREa_z,s 10 sF 02
~ ti ~or j ~ ~ ~1 C]7 ~
% TOTAL J EA=8,355 0 ~
LOT 13 ` f ~ ~
k+ rg.rW I0,117 Af V
v 56k 17+WJd7 1--
OFFS~ ° \ ~`,,'k \ } ~4
E1: OA L . S~ 14*2I,W ~ W
~ DA2 DA10 2 ~ x ca p
PER~Vi! AR =~2 Ob0 SF lA1PFRVIOUS- AREA=11,350 F w ~►~i ~ ' W ~
~ !~1 iO~ L $ AREA=4,~6C} c . rnc TOTaL AREA=64,568 SF 0,
co f ~
w Ll,T 15 cn
W.A if i \
~ ~ Iy t LOOTb7 ~ DA9 ' cn
i,tl47oT
~ DA1, ~ I~uP vio~s AR~=22,sso s~= w ,
_ I BM JNL
E -y ---WPMJGaS-~6=~~,4oa sF ro L AREa=90,625 sF
roTAL aREA~6,"f
U)
10114/01
~ ~I=FEW
6793M
LO ' SHEET t OF ~
H
1
' Summerfield East 41 Addition
Phase 1 Subdivision
1
,
1
'
APPENDIX III - SCS Soils Information
'
1
'
'
'
t
1
'
'
'
1
' 02001. Wyatt Engineeruig (679300) Storm Water Brief
October 19, 2001
'
i ~ _
► ~ . ~ • ~ ~ t~ rs ~ ~ , ' ~
- 5y~. ~ 4a, , l ~ ~~ii ~ ~ 1 ~ .r . ' ~ r
~ ~ • ' ti c7 ~ : ~ , ~:,-c
} ~ ~ ~ J F a,~ ~fi~.~ , ' . • ~ xh ~ .
- .eF t s~~~~•
i7^t~'~.y,~~'i~L4+t ~'a1"~ ~ ~~iP~}, x:yr,
j y ~4.a n1 ~~'~'~iy~~i9 i> 9 Z ~ ~ •r1° µ p~~'1~ : ~
a,^'yR~ ~ ~ ~ ra'«"~.~ tk y~v~", +r •1 '4r ! 4 ~ t~ ' - "~t
;S.i"~, ^ ~ x to~ t ~ :4~ dSs ~ ` { tti v~`~, . % ti K„` '7;y : 1 c 'F' t % ~ ♦ 'aq ~ r~ '~a, ~ '4~ ~
~,,,.'a•.-, y° _ q e ~'6 {~'i v', 'r ° , ~ ~ +~i~ ` ~4 ~,S .~k, ' > ~ ; ~ ~ ; t~ 3; - ~ • ~ 1 e e ~ • ~ 1~ i ~ ' aZ~ ~E~t~ ` N" y~ ~i
1 ~ . . ' t . ° - 4..~,` ro ~~i ' V „ . ~~i u: i ~ y '
~ a tC+ ."P<+• . ' , w~; , a '~:y~ ~4;,.1~4.~ `~.¢;,,,~~;e~~`~~a ~ ~..9,~. sp~,~~ ~ , ,b~~,~
e . ,4i. •1 Y'' ~ ~ .J~ xt ~~w .e . ~ ~t• 1'
,t.* ' ~ ~ A a+t M a~~`' • 1 y j"' ~~~U~'
, ' ~ t _ ~Vr_ .r '~k t.~R•~',~ty~: ~ ~ • ~ i 4' « _ e ~ n ~ , ~1~' t~ ~k~"1~'~
t''Y`~ya;it ' . Ye ~ ~ +~'"t~ ! r i r.{'~ ~ j~/r ~ ~ ~ ~ +v`• ~}~,~"~r'~ ilI ~~E ~ ~ ~ M• r~ "~`,a • i ,G ti - ~ 4'1) jr+x~
.1.;``
, Z{~._~,i{„~.AW' • M ~ ' • ill V y, '•N.~y fj, / ' ~t; OR ~ yx A S,^~ ) ~ •4~. 'M1 'y
et~a~. ~ ~ ~ r 4 1~ YYK ! ~ ,rp ~Jr Y } ~ F~1 ~ ~ ,rE r <tR~ Yn . ~A 4 ~ne" i,y y ,Y~m~ :'~i'i'M~
k
i _ ~ ~ y~' ;;~t ~ S`qy~LF,~F ! ~ jY' V:v^
kvti ;~:y~- {I'' j~~,~R ~f ^h~~ , •V~ 1,,,,~,...-''~_.~ tat~`~i
a~" I~ 3` r~~~ Y9Y' 1~ : f~1~ I `'1~' ~ ~ Y. • °~~V~ ~ ^ ~ $ ~ ~t. ; Y
'j
Y ' 00 5 t~ ~ R 0.~1 ` ~Tai1 ~{~y t3~ • ~ w 4~ ,p d'.. J, ~ l~a~~~~~5
1 ) * ~~.~,5~ ^ y~A~~ •r 1.1T 41w~,~, ~ a6NA'f4:~.r~ ad 't§~~'sJ`. <tr4.yy' ~ . .xY -s ~::~s~~° ` ' ~~~y~~". ~ x,°~~'.f
T ~ ~ t a , ~ ~ oi p{~ , • , y ~ it, *a~~
~ } t~. . . ° +~i" '.'R~j~ k ~ ~ / e ~}rk•rr~k.'t' ~~,,a,+.,~ ~'.,j ~f•~+ ,>1',~~~ ♦ ~i~ ~
1 = r ~ i'~ ~f f~~Y~'N ~ •~1
Ozi»
'~-^1P'~,~~iti~~`,ie~.~%~;`~-~ ~ 1;. 4 , a a'+M1,~'Y ~ t (.i. , I • t /i ~ ~y~. t 4 y~t.3i / ~ v~'~~~ ~F ~ ~o ~ ~ * i
~ A . , ~y ~t ~ ~~t3 ~ . ~ ' " • ' • • ~ ` ~ a~.~ ~
~ s t'Cl • ~ '~i . ,~T }~}~~*i: ~ 'y~t~~~;~a%~4: ~k ~~i
~ a `~J '
~~M1- A ~ ~ r~? S • : , b ~ T ~ f t~4
t~~ ~ `Y"Y £ ~~'i~ ~ r . / Y ~ ~ : aL' 1 ♦ ~B w , r~ . rr A t t . rrt > t .~j
i~~ pdYr.~: H '"i x a` ~ 1 ,I • 1 .C' ~ik• ~ @ ~ , `r
h ~ t ~ ~ h • } jw ~ z , m '
~ . ` ' ~ La» + . •y + F~~*
~t k ~i~~ .f y Jt~r , .dt.
03 \ ~ l 1 ~ G , f x G
l~'"
~ g •+~r _ , /1 ~ ~ ~03
~~fr9"" Iwvi~. . / J ~ • $ ~ , , ~ A : ~ J ~ ~1~.~ ~ 1
rIo 03
[Jtq ~.Y •
,r ~)~.F•1~i~~ v. . ~'~1+y~• ~~t .yY4; , . > ,y;s'A ;
K~rt t'~{ R : 4 ~ , ~ ~ ~ ~>,~'~t 4„ ;,Y` • ~
..~~'Lt~~X" t _ ~ } t ~ . . v ~ ~ ,~c, a. ~°„~i ~ 1 . . ~T ' .
~t ]`i3~~i,~~`y^~^~^^~ g t`~i'°Y.`U r ~ , 1i^ ~~'~l ~ i i, ~ Y1 ~ 1~y~ ^ >.:1! . ~ A aa~~'~e'~"•e >,~E ~
M,~,~,,..,,,,. b • n V r .r'~ ~tjt~~ 0~1,~,.~~.~ ~ \ Q E . • ~ z'~" ~5 c' y,. ~ .`x ~ ~ ~~'4'
' ;45 ; ~ d~ 1 1 3 u 1.', •i s ` 1 . ~ ^s yu a`, ~ g,y` ' ~
~ ' ~ t ° ~Y jU-}@~~' ~ S'•~i> ~ ~ 4 ~l:~ aF ~'1l' ` V
~ i, b d ~ M~ 4 t ~•Y ~r~~ ~ifi`+*F 'tav"q i ~ , : ~"$`~tp.t~~-~ .y~.• , ~ , 13'~~y- 9,~
x r f~ ' ~ , ~
Vrt~~
~ s~~ ~ 1 ~ s lv ~ i?~i" Y ~ ~
$ls X~ ~'ti t ~ ' Y , p~~-~4yy 4~ E ~H
M~ ' ~,'~~k:`~`~~ ~ F'" ~ ~j} ' ~ ~t~~ ; ~ ~ si,~g s ~ •,~~j~'~,, v Y.a
♦ ` ~R ~ ~ ~ .Yx~r' 'Y
(p
_ . - ~ ~ i~ • ~ . ~ . ,
~
Ral~ ~"~~~I.'
`a ; o} ~•`~a^ A~ s"~,~,~: a,~ ~~S'" .,D.~~ `
tf~
~ZtL
, . 's _~L7~ i~A~3•}~.,~!~~~'~4~''~~+`~i'~,° ~.'`~~~A~~~
' .
' 3POK6NE CCUNi'I, wGSwiNCfON USOA-3C3
7•97
S 0[ l •t X i C p~ 0. Q i 0 T! 0 N S R G C C R O
' Gqe CARRtSON CA6~QLlf {,OnM, O t0 S IeACGNT SlOVQS
CORRISON SGRIGS COHSISTS O/ '/~RY OHIP SCIl3 /Q0.M67 (N CIiCfAI 6UTW~SN WITM a Hanrte 0♦ VCICiNIC e5M ANO 10e55 GN LlYEL
TO ClNi~Y SlOP(NG iCFR6CIIS ONO S7lCP TO M00~R67~L• STHHV TERRACC DA[OKS V lGQ7oL[CM IS M6[Nl7 GRA13 AMO SC6T'GRl0STCNOS
O, T0.4C3 rYP[C?LIY, TMESQ SOIlS MGVB O OGRK GRGYI3M BNOWN 104N 9U0.lGCS Li'/GR SOOUT Ifl (!1 ~IIICK, 6 ER~WM GRLV=L~7 ~06M
' SUSSOIL 1 INCNI3 iNICK OND 4 eNCWM YQRY GRGVeII• IOGMVi ceease SaNO SYOSTNGTUM TO !O [NCMQS
i tSNOSCAP! ONO GLIMOTff PAO~ffpTIC1
6MN1(6l dIR fqC1i 1RQS ~ 6MNUOl llE~LiLOt1 ORi1NOCg i SLG9e j
~ iCVOReit1Re ~ 06YS ~ oqeGlVfT~7tON lrTl Gta13 fPCTI
~ a7.40 . t.0-IJO , IS•S9 " I.00•2800 ~ SE , o-S ~
' lSTIMCTCO SO[L PqOVlRTIE$
08pfN; ~121~T ;/44CT.:PCRCZH7 0/ MGTtRI4l ll55 ~CLOY
i(IN.II VSOG T!%iUR! ~ VNI/f!0 ' o03Hi0 >10 IN;I•IOIPI' TM6N ep33INC SIlv[ NO
I 1 ~~ectf ~~rcr• ~ a io ao zoo '(rcrt;
I o.1s1~p_~ ~SM, GM ~a-a ~ o i o•io ;so-ao 'ss•7 o so-so .o-so ~tZ•ao;
cw , SM ~a•z. e•~. a•a 1 a I c•~s ~as•~s ao-~o zs•so ~s•~s ;ro-
' ~is•~~'GRV-Sl. CRV-L. GN-l iCM
~~s•~otsn•c~v-tcos•cRr•st ~ ~a-~ ~ o-s o-so ~ao-eo 33•55 zo•so :o -xo
~eo•Te~ca:-cos, cav-cos, cex-Ls `G/, CP-CM ~e-1 o•10 o•.s ~1s-~s ~o•3s s•ta o-io
1 ; I t ( 1 I ' I
~0!)TN'ltOUtO PIGS- MOIST oUIK P6RMQa- AvGIiA►EIE 30{l SAllM1T'/ SSA i CLC i CG~CO7 i GtvSUM y
IM ~lMIT ~TICLTY~ 0lMSITY i OIIfT♦ 'WATlR COaC(TY~ RlACYION I I ~
i ~ ~INOC% I (C/C.V71 ~ I{N/MRI ~ IIM/IN! Y SINI ~(MMXOS/CMI~ • I(M!/tOOC) ~ IOCT} ~ ~►tTl ~
' O•1!' I0~70 NP-S 1:13-173 ' 0.{•2 O O.I:-O.IS S.r-7.1 . . d . .
~is•sa~ to•sa ~N/-S ~ i.zs-1.as ' o.e•1 0 ~ o.oa-o i2 ~ ~.i•.a I I I s.~o I I' i
~ ~io ~ o.oa•o os ~ a ~ 1=_6 t t I
~sa-so~ ~ aN V v ~ ~ i » s s - -~.~o Y
~so•7o1 ~.rs ~ >zo ~ o.oi•o.o~ ~ s.i•7 a 1 ~ I o.2 I 1 I
I 1 I 1 I I I I I ! 1 !
1 1 1 1 t I I I t t , I t
' ~O~ITMi00.GANIC' SNR(NK• CNOSION WINO WINO COR0.05(VITY
~(IN I~-oTT6p ~ S~MCIL i ~oCTOR3 iCNOO i GA00.
~ (PGt~ t707aNi}64! F Kf~ 7 ~GAOUV~ INOlM ~ 57EE1 :COMCAlTCi
O•IS' 2•S LOW .IT'.72I ' 2 1 { I • 1 MODlR6TC: LOw ~
~is•ss~ ~-x ~ Law ~.is! 1Z 1 .
.•~o~ ~ tow ~.~o~.~s; I t ~
yao•TO~ c s f Low ~ os•.zo' '
, ' 1 I I 1 I
l l { i I 1
~ r1. oootnc MfGN WLTCR 74D1! ~ CSMEYTCO PP11 : SEORGCK ~SUOSfOCyCE NYOS'V0T2MT'L~
OtYTM %INO NONiN$ I0liT71'NONOnlSS'DGVTM NARONG33'{N[T.'TOTeL~GRP /ROST ~
~ 1NlOUNlMCV OUROTIGN ~MONYNS f{N) ~ ! (IM~ ~ t((MI IRfMI aCTION ~
~ YOC >60 • . 'J :MOO[R0T°~
SGNITAfI♦ /OCILIT[~1, '[CNST0.UCTION MGTlR[GL,
seyeae-roaa rtLrea icaao ~
~senrtc ~
~ sesoarrrtnarK n ~ t~ aanort u
I ~►teLos ~ II I ~
~
~ seveae-scerace ~rwaaae~e ~
~ sawace ~ 11 I ~
' ~ ~ACOON ~ ssNO
~ aRCas
~ ~saveae-seevace ~,raoeaeLe ~
~ saMtrsnr ~ ~ {
~ LANO/ILl GALVEL ' i
(TRQNCMI
a SGY!RG-5@@/4G! i; iPOOa•SMYII STOM65,ORlA RRCLAIM I
~
~ SN
~ Lanc{TraR~ ~ II rorsocL ~ I
~ Ina~~t ~ 11 I • ~
' ➢OOR'SMLII 370Ml5 II -TER MnN6LeNlMT
~ 06IL• ~
~ co+e~e iaA ~ II jscveae•scc►aca
I
i ~pNO/fLL i q!3lilVOIR ~ '
It OREA i (
OIIIIDINC
I 4ITG Ol~VlIOPMCMT ~ ~
' $lv~A~•CUTL4NK4 CAY! sdrRRe•S~e7acG ~
!MlANKMQNTS i ~
~ :NOLLOW "
ltx tavaT1 ons 1 ~~~evees0 ~ j
( I I1 I
~ SIICNT slvERG•NO wnTlR ~
~ owe«cMm ~ ~ cxcavar¢o ~ 1
, ~.easeM6nrs i i~40Yi~lAS~QO ` j
~ SllGMT i~ i066P TO WaTlA ~
; OWlLIINGS ~ '
W[T N ORAIMAC! I I
OASlMGMTS
~ s~icHr ~oROUCNrr ~
~ COMMlRCI6l (R0.ICGTtON
; 6U[IOtMCS
~ NOOlAATC-fRCSY ACTIGM ' 'LARCE 3SONl3,T00 SoNO'/ ~
~Q~Q~ I TlARACQS i I
AOS RlLTSO 0[v[ASIONS i ~
i 0.3T
~ ~ LOWM3, MOOCRGT!•SMDIL STONGS,DROYCMTY ~i iI~RGE STGNIIS,7ROYG1ITY '
~IONOSC~VINC ~ 'I GAGSSCO I (
ano o cir wasenwars ~ I
ratxwars
' • .
'
' C04 C?RAISON GqAVEILI lOOM. O iG S PGAC. Ni SIOPQi USCG•SCS
, 7-92
R[CAlAiIONOI OtVlIOPMEVT
j ;MCOQRGIQ- QYSTY i~ ;9eVLRt'!N4\l 3TONE5 i
' i ccMV AACOS ~ 4'vLorcaounos
I 1 II 1
I ~MOOeaora•ousrv ~
1 Inccaaora•ausvv ~l PaTNS i I
;VICN(C OR6o5i O
TRAIIS
CSi6LIlI7Y iN0 1I16lOS P!N iGRE Or CROPS,6M0 063TI1NC IMIGN LEVCL MYMaCEMEMiI ~
CAaSS, SEHO~
LOP6- wNE17, wMa~Ai, E4AlCY GRGSS• poSTUqC CaiS i~
~ et~irr ~ wtHren ~ svtHC ~ ecuNe Mer
{svi ~ ~eui STCNSR' ~ (nuM) ~ raut r~esi ~
, INIRR.'!RR `,N[Rp ;[AA ~N(RR :IRR ~VfAN :IRR :NSRA ;tRA ~4 1RM ;[RR. ;YfRR ~i4A '4 1 4R ~(R0. `
, 15 ~ 3a ~ 70 CO i 70 60 20 1,0 a O 2.S i.0 30 ; •00
~ 1 I I I I l i 1 I I 4 t i I 1 . ~
, wCCOLGNO SufTA9tLITV
' i ;ORO~ MANBGlMENi I40olSM5 ! oCTEM[[At P0.00LLCTIYlt'I
$YM EA05'N'EOU[V.;3lEOL 'WIMDTX'1LONT COMMON TR!!5 SIiG;7N00! TRelS TC PIGMT ~
~ j ~Ne2GNC~L[NIT !~C0.T'Y~M4ZJNO~COMPCT! i140%:C163 ~
•A'Sl[GNi'1100ER.;N00lN.'SIIG>1T'M00lR.'iONOCR040 PINC •i 4 10NOEROSO ►ING
~ ~ ~ ~ ~ ~ ~ooucLns•rca
1
1 I I I I 1 t { 1 1 1
i I 1 1 I t 1 I . 1 I 1 1
' f I I I I I 1 I I I t t
{ f 1 i i 1 t I I 1 I I
1 1 I 1 I I I I I I I I
I l 1 1 t { { 1 1 I 1 I
I I I I I 1 I I < < I
I I I t I I ' I ! t l i
~ ~ ~ I I I j I I I I I
' ' 1 I I ~ I I l i ' I l
~ f' I i I I I 1 1 1 I t
I I 1 I I I I 1 I I I f
~ I I 1 1 ! t { I I 1 1
wcrpeaeaKs
' SPeC[!S :MTi SP[CSlS ~ MT' SYCC2lS 'MT; SVlC[!5 ~NT
PQKXING COTONdASTER •~URGVEON VRIVlT jI 6 j5[SlR1GN /EiSNRUS i 2 10'l(LOC
~ROCY M7. JUM(I~R ~iSi NU33(ON-OLIV! 84USTAION P[NG 1~GRECN AS
N M
; 'DOO~AOSJ ►ING . 2DiSC0TCA PlX6 i70iSISLR[oN ELM i70ill~Clt LOCUST
1 • I I I I I I I I I
W[IOII~~ M0.61T6T SU[Y06[l[TY
, PD7ENT[ol ~OR MA017oT CIEMGMiS OOflNT(Jl 65 MplfiiT /OA:
~ 'GRA[I/ RG55' WIlO A0.0w0 CONI~lR'ShRt705 WCTlaNO'SMOIIOw'aPGNLC WGOGtG WlTl4N0'RYNGllD~
i ~ SE[0 .ICCUMEl~ MlRO ,M7R~l3 ~PIONTS ~ {iPlPGNT3 ~ WOTER ~W[IOII iWfIOI/ ~WILCI~ ~WflOlf i
Fo[N fG[0. i CO00 i /41R i /Af0. i F OIR ! OCM1 { ~ V. 700R' /A!N /AlR i~ Y, IOON'
~
~ ~
DOTENTf6l NATIV! VIOMi COMMUNf7Y SpGNCClSNO OR /00.E5T IINOEA57qR♦ Y[CETAifGNl
pLp„t ' oFRCGNTAC! CGMpOSITfOM OR11 WlIGNTI '
I CONMON PIONt NOME I S7MOOL , ~ ~
fNlSiMI ~ i
~►INlCRGSS C?RU b ~
~e~ue wtLoare ~ s~eL ~ s
, ~svtKe TR[SlTUM ~ rasna ~ s
~aLueauncH wnnnvcanss ncsr
~sweersceMTeo eeosraaw ~ caraa
~svacsatnc swaernoor ~ ascH
~naaK vto~er ~ rtao ~ s ~ I I I ~
~s~Kr Lurcne ~Luse• ~ e I I I 1 ~
' ~COtMMON SNOwSZRRY ~ sr4~ ~ 30 ~wxtre 3PIRQA ~ sveez ~ s ~ _ ~ j
iSSSKATCGN SCRYSCl6lRR•
00.lGOMGRAI! 0lRC 7 ~
~OWPN/ ROSC
~COMMON CNOKGCMlRRY ~►RV( ~ • I ~ I I `
isIACK M6WTMGRN ~ C0.00]
' I►OTpNTIGt VROOUC7ION 4LD3./PC ORY WTI• ~
I4YOp0016 YlORS ~ O30 ~
~ NOAM6l TEARS ~ i80 i i ~ I ;
~ UN/DYOR40L! TBLRS I -00
RYNGL 9IT! 047%Y002wa
/CpTNOTQS
QXCIISSI'/! ►lRMCAO[llTY NATC M4'I CAUSC ►OIIUTICN Or CAOUN Wa
S E% 2 1CN
iTL IMD3 0 3UMMGRY 0/ ! OR MOR! MQASURC MlNT~ ON iN[9 SOII.
1 , .
, ~
~
~k sPaxa~le Caunsr, wasHyHCYaq ' uson-z~g
7•32
~ S 7 [ L I H T C R 1 A ! i a Y I 6 M 3 A ! C O R D
Gme $nARS59N ■!RY GRAY~LLV LOaM, 0 T6 5 PlRClnT SL qA(S
G?,AAyS6N S~R[~5 ~C]ky(g75 p~ Y~Rr Q~~A SC[15 ■ORMfG IN GkACIIIL CUfw~a3lf MfITN 0 1k6N7LE OF YOL~^XN[C ~15H dKd LClSS O11 LCN!L
7[1 GCKTLy gy0➢[NG LERAACt 3 Al1d 914CP S¢ M40ERAiSLY 5T4QP T6ARRCa aRERK3 Y!C£74T[ON [S MAIMGY GAR58 Ax0 3[eTTERCC ST+~P~CS
~ Or 736!5 LYPf[0.LL■ iH~SR S~dLS M6Yt 6 O4RR 4RaY]3M eRawK 40aM SuR!'AC8 L4YlR R9du7 16 CM 7M1Cx, a$qqw~1 CaAYaLLY LQ4M
SlttlSiQjL 8=HGN(S T'~SCiC 6yQ 6 aq6w1~ M'rqy GRA'lCLLY LQqMp CQpA¢$ $dNp $ijp57RpTYM Tp rQ fN~~laS
L.7NOSC3A9 y,HQ CLEF18Ti~ PR6P!RTEES ~
~ AHnlla4 6[R fNOSY FAmE ~ oMqUAL LLEY0.7[OH ORG6NACp SLCP=
T!MP!p6TURC ~ EAr Pq,QCIPITA7t~N ` fNY1 CLSSS fPC:I
iY-Sa . 17O.I~ ~ T0 . IS-7S ; 7400-2Ba0 ' SG ; o-g ~
C57SFl0.TE4 SO[L >RQPeRTtd3
iOCPTH~ ; ; ~FR0.E7 '1RaC7 'AEaCgHi 6F M87lr7~.34 SlSS ~[La1' ~
I[[N sA LtSOa il71St1AL I liti[FyEO ' ASSXTp ~sla IH~I-~811{! YFiati PnSS[HC SIEVE An
I acre ncr! , a 10 aa xao 'raeri'
a-ia'C+er•r, CN 1-~, A~2 ~ O D• ~ ID •O-SO 'SS•Sa 'SO - iy 'x0-3$ ~p,•jp~
~ `ISG8Y-SL, GAY•t :R•L ~GM. SM ~9•Y. R-1, A<i A ~ QIS ~AS-7S ■~9•Ta 25•30 IS-aS ~SV-]S~
I.a-6OI'J1[•CRN-~~Q3•ERY-SL ~e. ~a-i ~ o-s ~3o-so ~ae•ee s3•ss xa-io iw zo
i39-79~GR%-C65 e~ev-ees. eax-Ls ~ev av-e~ ;a-i E o•io ~~v-as 1P-15 s•xs a-~a j o-s ~
`GlVTk:L[9li[d ~PLAS+ MO[ST luLR 7lRMlA- AYAILADL4 SO[L iaL EN ITI' S.~Pi C!C CAC03 GYiSUP1 ~
1M 4ZM[T T[C[TT~ O~NS=71i ! aItjiY ~WAiqR C~roCaYr~ RQ'aCY[6N ~ ~ ~ E ! !
1 I o - is' xo.sa 'HVOSx ~'sascMl~s ~"utsVZ ~a"fNSa t s sP7Ia It"m"'os"cr~t; . 'i~+~/'aamt; racrl ~ rvcr}
~is•a~i xa•xs iHr•s t~ as-" as = e s•a e i oo
~ e es•a i3 t s r•~ a~ I I s.~o I I
`aa-~o~ ~ nn 7s-s sa ~ s7n ~ o o7-a oa t s.s - T a I I I=,~ I E
Osa•xo~ - ~ NP ~ i ss•~ zs = :xo ~ a 01•0 o~ [■.1•~,x a_i E ~
I I I I t ! t i I i d ~ !
I I I I I I 1 I I ~ ~ I E
~ ~QliTN;0RC.7f1lC' SNAIHK• QR03FON w[716 ' w[hp CORAf15[Y[i■
![]M I :NaS7@R ~ ywQI < < RACT6R5 lQRQdaROU ` `
lPLY1 `PQTZ'J[ii1t= If : K!! T!GWOUPE SX6lY ` S7EPL :CQMCAETlE
~ O•IS' 2•S L9W IS' 2d' Z 7 ]S NOOLR67~:- LGw ~
3-a4! r•~ i L~w = 13~ 32~ !
~ai.6C; CS ~ 1. 9W 371 `Sa-Ta~ i S ` 1. 4w ~ OS` ;Oi
r E ~ '
FLO90iNG i HfGk woTER r0lL! : C!MlNTlG V6M i
: ~[OROCK 'SU9SillC~NCE N10!'POTEMT'L~
ClPPff 1CIH0 ;TSONSFS 6~PTM'tEI8AIIN~SSa~~PYH r{AR~N~55'IN[i T0p4LCRG1 FROST ~
E rRC0~1lVC■ OIIRSYIQN .'f1ONYkS i (1T1 I I ( IN) e THI ! r [M1 I ! »YtC]X ~
MeME . f6 O . . . . )60 9 'M13QlR6T8~
StlN[TOpY IeCSt[T[ES1 cnHSrnucrtox MaT!ltSBt
~
senrtc xaAIK Isevexa-paaa ~ELrrtn I I Yeono
~ S
~ aasaRrrloN I II qCnorzLG ; ;
j rteLos ~ II i f
= i . .
eYcpe-$deDOG! Y49SARLZ
srwACa Iy' II [ i '
~ tsceaM I II saH~ ~ p
AIeSaS
i I II i I
~ saraxies•seapac~ r~aeas~e ~
f saxirear I ll I Y
1 ~ 6dH0/[LL ~ GRaYeL ~ , I
~ [YR!utrk I EI i !
r SLVlRl+SlqiAG4 ApOR•SMnLI '~Tpx$5,aR4A RSCLR[M
~ ;SA MIY¢R• ` " ~ i
~ LqCF[LL T6PSOIL
~ SARIS61
~ I I EI I w i
~ Poaa-sMaLr. ssanEs
~ po[Lr Y naew .ewnea.err
~ COVlR FOR SlY9A9•S99PAC4
~ tiaKOxtL L ~ i~ rexn ~ ~
I ~ I! R~saaro:re ! l
II A Re4 f I
~ nug~o~HC s:re vsrekavr~e.r i
5!Y!R!-{U731RMK5 CAYG S;YSAt-SEEP6G4
~ 3XALL~W ~ `lCH3ANKNBNPS ~ Q
~excararlons ~ i6 o[kes nHO ~ `
I I LEYSm 3
d i II i E
sltcwr
iaitr(q(-q4 wo1YER k
~ ~ 9w6LL[NC! ~ eYCdraTa~ I
~ wsrNCUt' I ~I aaaos r ~
~ eas+3M~rrs ~ Ilaauir¢a rae = !
I I II i f
tLtHGS jsLicnr SnaeP rc wnrax
~ owC II I
I y~=Tn I II pRAfNWG4 f ~
eBSaa+arrI ~ 19 S !
` ~~rsoeAavE-seove `xtesa,owauaHrr i
S#ALL
~ eoe+wext=aL I I~ taeaseA ri¢H ~ I
F eus<osres ~ il E E
R I I~ ~
M0O9RA7!•iR057 aCSZCM E'ARLf SFCM45,TOG S.SIfOY 1
LocxL I II reaRaces I
R Raaas aNo , ~ sMp I
~ sTfie[TS t ~I otv!ASIOqS 6 ~
1 i II I I
~ LRWNS, 5@tl!A!-SlRRLL ssenes L~aca srnNes oaaucNrr ~
1 ~ta~os~ar~na ~ '3 :wassro ~ j
rnn c¢t,~ warenvrars
~ ra[awprs t 1~ I 1
~
'
' cne caqNtsar vCar Cqav6Llr taan, o to a vlRCEnr SIOVES usoa-SCg ^
7•9j
N3 GA~oiSONGI 0lVCl0►MlN7
` :MOOQ0.a74-OUST'/ ;SlVQAQ•SMGLL iTONlS
i CiMP aAl~S ; i~f~AYGAGUN05 i
{
' f
t~QCfl0.aT6-OUSS`f 1MC0lRAi!•OUSTY ~
7aTN4
ifCNIC GACGit ~ LNO 1 ~
TN4113 i . ~
' GSOaOILITY SMO '/(!LOS P!R ACAE 30 CAOVS 6M0 Pp5TI1N! IHICH L0VlL VGN4GEMENTi
CA➢4- WNEGi, WN~qi, O4AlLY CAGSS• : VGSTURd CStS ;C1.~55, SlEO;
!t~(T7 ~ wtNTI R S7AING ~ ~l[CUN! N6Y
re~i reuI ~ Iau~ ~(raxst ~ reuNi feul ~ jL esI ~
, I .NIRA-[RR ~NIiR 'l0.N ~NfAA ~SPR iNiAO ~iAR `4tNA itRR ~NIq0. ~IFR :N[RR ~IRA 'NfiF IRR i
7E ]G ]o !O 70 io So I O a O 2 o S.S 20
, ` •i i i i ; i i r i i i ~ ~ ~ s ;
i i i i i i i t i i t ► s ~ , i
, . , woooinMO 3 U[T6![LlTY , • , , ~
' ORO' MAMAGfMENt sqdelQMi : VCSENT[Al PAOOUCTiV(Tv
( ~S5'N'lOUI7.:SCLOI.~W{MOTM'V~YNT COMMON iRCH3 S(TG;PR00~
7RCCS TO DtidNT ~
YM~8R0 Y~ ~[NCI[!C104, i
i ~ ~N62JROit[MIT :MORT'YiN~26qO,COMP[
~ I aaISLIGXtiMOOQR.iM00lR.;SL1GNTiNOOLA ~oONOl0.C3~ 71N! i76 •i a iDONOCROSS ►(NG I
I I I I t 1 1 ,oauc~aa•rta I 1 I I
1 I 1 I I I I I I 1 I I
' I 1 I t I 1 t 1 1 1 ! 1
1 f ' l { { I' i I I t I
i I 1 I t I 1 1 I I I
I 1 I I I I I I i i I
{ 1 1 I I 1 I I 1 I I
I I I I I I I I 1 l 1 I
1 I l { f i 1 1 I I I I I
I I I I I I I I 1 I I 1
1 I I 1 I ! I i t I I ~
wINOeaeaKs
• SPEC1lS ;MT1 CiE4 ; NTi SPlCICS IXi' SYECIlS ;NT
VCKING COTONC.ISTER {~CUROPEINSTlPRIVET 0 S[eCNIiN PlASMRUE IO'L[LGC 11~
~ ~NOCX7 MT JUN[VEA 'IS:AUSSfAN-0llYE 'Ib' oU4TRtoN i4NC ~2S~LRLEN GSN i
25~
' i 'YONDlROSG ►IMG i28 i3G0TCM ►[H! i70I3lo0Rl4N !lM i70i9laCK lOCU3T i40'
' W[lOl[/C NGe1TLT SUfSaelL tT'I
' i0T!YitAL FON M00(T0T !LL'MlYTS ! POTlNTfAI 45 X60f707 /00..
~ iCA6lN ~'GNA55 t' wILO ~NANOwO CON[/!N'SN0.U03 W[TIOMC'SNOll6w'CVlNLO WOOOID WlTLPND~A6NCHl0~
1 t SE~D ~LECUM! ~ NCRO ~ TRElS ~PIANiS ~ iVIANTS ~ wG7EA `wILOLf ~WIIOI► iWfLOI/ :M~ILOL/ i
fCiR i F A[0. GO00 P41R FOIR i I41R { POOA j~ Y. POOA' rAlR i IA(R jY. PGCR(
'
~ ~
~
907lNTlIlI NG71VS PIANT COMMUNITY lqGNGClANO ON /ORCST UNOGASiCR1' YlGCTGTIONI
VtGt17 PCpCSNT4CE GOMVpSIT(ON IORY W!lGMTI
i COMMGN iIANT N4MC ; ST N lM8 p
30l i
. tM1 .
~Ineecaass ~ careu
r I 3 I I I I I
' ntuK! T0.Iwtto3larTe
UM T e R tcP t 2 S
S► s
i i S
el[VlOUNCN 'NNlATG0.6S5 ACS♦ S
~swcerscn~rao eeo:rRdw ~ carns ~ s ~ I I I ~
'SORQAOING SWCLiFOOT pSCN ~ S
~NOOK rIaLar ~ vtao
I s I I 1 1 ~
~stLKr turine ~ Lusas I
' ~COMMON SNOwDlNl1Y ~ sroI so ~ ~ I I
~wNrre svtaea ~ sveez 1 1 I I I
;sasKaiaaM 3lRY[CC66RRT ` nwai2 I ° I I I 1 ~
IONlCONCNAV! ~ eeae ~ s ~ ~ ~ ~ ~
COMMON CMOXlCXlRAT ONcVI 6
~eLacx MGWTNOAN ~ caoox
, ►OSlMTIA1 VROOYCTION (L3S./3C. O~IY WTI: r
~ rnroaaste reoas ~ eao
; NGRMAL 7lGRS ~ aoo
UN/GVOR6lLG 'I[QRS •GO
RGNG6 SITC 047XY002w4
IOOTNOil3
, :!%CC33[YQ VlAMCPO(IiTY RsT! MAV C4USG 70lLUtION O1 GROUN WDTlR
SjT! IMDLX ii A SUMMaRY 0► 3 CN MORE MlASUNlMlNTS ON TMIS SOfL.
'
,
~
' Summerfieid East 41 Addition
Phase 1 Subdrvision
,
1
'
~ APpEND1X N- Rational Method Calculations
'
1
'
1
'
1
~
,
'
1
,
Storm Water Brief
' m2001. Wyatt Engmeenng (679300)
October 1, 2001
1
, Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA1 wb3
Date: 10/19/01 Page 1
Name• SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-1 Design Frequency = 10YR
No of Subareas. None
' 1. Determine Time of ConcenUation:
, Segment 1- Overland Flow OVERLAND FLOW
Length, L= 70 ft(Length) MAX LENGTH= 300 ft.
Slope,S = 0.01 ft/ ft (Slope)
' n = 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Gwdelines for StoRnwater Management".
Tc1 = Ct'(L'n/(S^.5))^(0.6), From "Guidelines for Stormwater ManagemenY".
, Tc1 = 0 93 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER
' Length, L = 0 ft
Slope,S = 0 005 fU ft
n = 0.014 Roughness Coefficient
Depth, y= 0.080 ft. (Assumed depth of flow)
' Cross slope, s= 0.02 ft/ft
Z = 50.00 fUft (Z=1/s)
Area. A= 0.16 ft. (A= 1/2'(Z)'(Y"2))
' Q gutter = 0.15 cfs
Velocity,V = 0.97 fUsec (V= Q/A)
Tc2 = (Length)/(Velocity)
, Tc2 = 0.00 min
Segment 3- Channel Flow NONE
, Length, L= 0 ft
Slope, So = 1 ft/ft
n= 0 012 Roughness Coefficient (Manning's)
Diameter = 0 inches
, Area, A = 0.000 sf
R= Dl4 = 0.21 ft
Velocity, V= (1.49/n)'(R^2/3)'(So^1/2) (Manrnngs Equation)
' Velocity, V= 43 62 ft/sec '
Tc3 = (Length)/(Velocity)
Tc3 = 0.00 mm
' Total Tc = 0.93 mm
~
~
'
'
1
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA1.wb3
Date 10/19/01 - Page 2
Name SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION. PHASE 1
Basin Name: DA-1 Design Frequency = 10YR
No. of Subareas: None
' 2 Determme Weighted Runoff Coefficient (C) and Area: •
' Area
SurFace Type (sfl (acres) C. CA
Open land (2%-10% slope) 2,031 0.05 0 30 0 01
' Roof & Sidewalk 2,510 0 06 0 90 0 05
Asphalt, Curb & Driveway 2,400 0.06 0 90 0 05
From Bypass DAx 0 0.00 0 98 0 00
' Total Drainage Area 6,941 0 16 acres Sum CA = 0.12
Total Impervious Treated Area 2,400 0.06 acres
' From Table 1, Page 6-2, "Gwdelines for Stormwater ManagemenY'
' Weighted C=(sum CA)/(sum A) = 0.724
' 3. Determine Peak Runoff (Q=CIA):
Dura6on (Tc) = 0.93 min. Weighted C = 0.724
' Intensity (I) = 3.18 in/hr From IDF curve for Spokane, WA
Area (A) = 0.16 acres
Peak 10 YR Discharge (Q) = 0.37 cfs
1 4. Determine Volume of "208" Swale.
' Total Impervious Treated Area = 2,400 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 05712 in/ft
Required "208" Swale Volume = 100 cu. ft
' 208" Swale Bottom Width 2.0 ft Irregular s¢e - see site plan
"208" Swale Bottom Length 50.0 ft Irregular size - see site plan
"208" Swale Depth 0.5 ft
"208" Swale Side Slopes (X:1) 4.0 ft
/ "208" Swale Bottom Area 1000 SF
"208" Swale Top Area 3000 SF Conservative Straight Wall
"208" Swale Volume 100 CF POND SIZE CHECKS
~ .
1
'
'
'
1 ,
, Rational Method and Detention Basin Design Wyatt Engineering, Inc
DA1 wb3
Date. 10/19/01 Page 3
Name. SUMMERFIELD EAST SUBDIVISION
, Project: 4TH ADDITION, PHASE 1
Basin Name. DA-1 Design Frequency = 10YR
No. of Subareas: 0
' S Determine the Maximum Outflow (Qo)•
, Number of Type "A" (0 3 cfs) Drywells Required• 1
Number of Type "B" (1.0 cfs) Drywells Required. 0
Outflow (Qo) = 0.30 cfs (SEE ATTACHED CALCULATIONS)
~ 6. Determine Reqwred Detention Storage Using Bowstnng Method
' Time Increment = 5 min.
Elapsed time Intens. Qin Vol. In Vol. Out Storage
(min) (sec) (m/hr) (cfs) (cu.ft.) (cu.ft) (cu.ft)
' 0 93 55.9 318 0.37 28 0 28
0 0 3.18 0.37 0 0 0
' S 300 318 0.37 117 8 109
10 600 2 24 0.26 160 64 96
15 900 177 0.20 188 123 65 •
20 1200 1.45 017 204 181 23
' 25 1500 1.21 0.14 212 235 -23
30 1800 1.04 0.12 218 290 -72
35 2100 0.91 0.11 223 344 -122
40 2400 0.82 0 09 229 403 -174
, 45 2700 0 74 0 09 232 459 -227
50 3000 0 68 0.08 237 518 -281
55 3300 0.64 0.07 245 584 -339
60 3600 0.61 0.07 255 654 -399
' 65 3900 0.61 0.07 276 744 -468
70 4200 0.61 0.07 297 834 -537
75 4500 0.61 0.07 318 924 -606
' 80 4800 0 61 0.07 339 1014 -675
85 5100 0.61 0.07 360 1104 -743
90 5400 0.61 0.07 382 1194 -812
1 ' Storage =(Vol in. - Vol. out)
'
~
1
,
'
,
, Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA1.wb3
Date: 10/19/01 Page 4
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-1 Design Frequency = 10YR
No. of Subareas- 0
' 7. Determine the Minimum Required Depth Above "208" Swale•
, Required Detention Storage 108.8 CF (See Bowstnng Method, maximum value)
"208" Swale Volume 100.0 CF
Reqwred Storage Above "208" Swale 88 CF
' 208" Swale Top Width NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 3000 SF (See "208" Swale Volume Calculations)
"208" Swale Side Slopes (X:1) 4.0 ft (See "208" Swale Volume Calculations)
' Depth Above "208" Swale 0.10 ft ASSUMED
Detention Pond Top Width NA ft
' Detention Pond Top Length NA ft ,
Top of Detention Pond Area 3000 SF
Volume Above "208" Swale 300 CF POPID SIZE CHECKS
' 8 Detertmne Length of Curb Opening:
Q = 0.56'(Z/n)'(S^1/2)'(d^8/3)
' Flow, Q= 0.37 cfs InGuded Basin DAx Bypass
Slope, S= 0 005 ft/ft
n= 0 014 Roughness Coefficient
, Cross Slope,s= 0.01 fUft
Z = 1/s = 100.00 fUft
Flow Depth, d= 0.083 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC FLOW (CHECK)
' a) Curb Opening at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenP")
' Cufi Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 0.37 cfs
Flow Depth, d= 0 083 ft
Length of Opening = 2 ft
, Use Q= 3.087(L)(H"312); Solve for H
Depth , H = 0.15 feet
' H/h = 0.30 O K. - H/h =<1
lIUse 2 ft curb opening I~
1 ~
~
'
, Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA2-3 wb3
Date. 10/19/01 Page 1
Name• SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-2 & DA-3 Design Frequenry = 10YR
No. of Subareas: None
' 1. Determine Time of Concentration:
' Segment 1- Overland Flow OVERLAND FLOW
Length, L= 40 ft(Length) MAX LENGTH= 300 k.
Slope,S = 0 01 ft/ ft(Slope)
, n= 0 016 Roughness Coefficient (Pavement)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Stormwater ManagemenY'
Tc1 = Ct `(L'N(S^ 5))^(0.6); From "Guidelines for Stormwater Management".
' Tc1 = 0.46 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER ' Length, L = 80 ft
Slope,S = 0 009 ft/ ft
n = 0.014 Roughness Coeffiaent
Depth, y= 0 090 ft(Assumed depth of flow)
' Cross slope, s= 0 02 ft/ft
Z= 50 00 ff/ft (Z= 1/s)
Area, A= 0.20 ft. (A= 1/2*(Z)'(y^2)) •
' Q gutter = 0 28 cfs
Velocity,V = 1.41 ft/sec (V= Q/A)
Tc2 = (Length)/(Velocity)
~ Tc2 = 0 95 min
Segment 3- Channel Flow NONE
Length, L= 0 ft
' Siope, So = 1 ft/ft
n = 0.012 Roughness Coefficient (Manning's)
Diameter = 0 inches
Area, A = 0.000 sf
' R= D/4 = 0.21 ft
VeloGty, V= (1.49/n)'(R^2/3)"(So^1/2) (Mannings Equahon)
' Veloaty, V= 43 62 ftlsec
Tc3 = (Length)/(Velocity)
Tc3 = 0.00 min
' Total Tc = 1.40 min
'
,
'
'
,
, Radonal Method and Detention Basin Design Wyatt Engineering, Inc.
DA2-3 wb3
Date: 10/19/01 Page 2
Name• SUMMERFIELD EAST SUBDIVISION
, Project 4TH ADDITION, PHASE 1
Basin Name. DA-2 & DA-3 Design Frequency = 10YR
No. of Subareas: None
'
2 Determine Weighted Runoff Coefficient (C) and Area: _
' Area
Surface Type (sf) (acres) C' CA
, Open land (2%-10% slope) 5,715 0.13 0.30 0.04 _
Roof & Sidewalk 1,730 0.04 0.90 0.04
Asphalt, Curb & Driveway 4,970 0.11 0.90 0.10
From Bypass DAx 0 0.00 0.98 0.00
' Total Drainage Area 12,415 0.29 acres Sum CA = 0 18
Total Impervious Treated Area 4,970 0.11 acres
From Tabie 1, Page 6-2, "Gwdelines for Stormwater ManagemenY'
Weighted C=(sum CA)/(sum A) = 0.624
, 3. Determine Peak Runoff (Q=CIA):
Dura6on (Tc) = 1.40 min. '
' Weighted C = 0.624
Intensity (I) = 3.18 in/hr From IDF curve for Spokane, WA
Area (A) = 0.29 acres
' Peak 10 YR Discharge (Q) = 0.57 cfs
4. Determine Volume of "208" Swale:
' Total Impervious Treated Area = 4,970 SF (Includes 0 ft2 bypass from DAu)
Reqwred "208" Swale Volume = Impervious Area x 0.5712 iNft
Required "208" Swale Volume = 207 cu. ft
' "208" Swale Bottom Width 2.0 ft Irregular size - see site plan
"208" Swale Bottom Length 1650 ft Irregular size - see site plan
"208" Swale Depth 0.5 ft
' "208" Swale Side Slopes (X:1) 4.0 ft ,
"208" Swale Bottom Area 330.0 SF
"208" Swale Top Area 990.0 SF Conservatrve Siraight Wall
' "208" Swale Volume 330 CF POIdD SIZE CHECKS
'
~
,
'
1
, RaUonal Method and Detention Basin Design Wyatt Engineering, Inc.
DA2-3.wb3
Date: 10119/01 Page 3
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-2 & DA-3 Design Frequency = 10YR
No. of Subareas- 0
'
5. Determine the Maximum Outflow (Qo):
' Number of Type "A" (0 3 cfs) Drywells Reqwred: 1
Number of Type "B" (1.0 cfs) Drywells Required: 0
' Outflow (Qo) = 0.30 cfs (SEE ATTACHED CALCULATIONS)
6. Determine Reqwred Detention Storage Using Bowstring Method
' Time Increment = 5 min.
Elapsed time Intens. Qin Vol In Vol Out Storage
' (min) (sec) (in/hr) (cfs) (cu ft.) (cu.ft) (cu.ft)
1.40 84.3 3.18 0.57 64 0 64
' 0 0 3.18 0.57 0 0 0
5 300 3.18 0.57 186 0 186
10 600 2.24 0.40 250 0 250
15 900 1.77 0.31 292 0 292 '
' 20 1200 1.45 026 317 0 317
25 1500 1.21 0.22 329 0 329
30 1800 1.04 0.18 338 5 334
35 2100 0.91 016 344 18 326
' 40 2400 0.82 0.15 354 41 313
45 2700 0.74 0.13 359 58 301
50 3000 0.68 0.12 366 81 285
55 3300 0.64 0.11 379 120 259
' 60 3600 0.61 0.11 394 167 226
65 3900 0.61 0.11 426 257 169
70 4200 0.61 0.11 459 347 111
75 4500 0.61 0.11 491 437 54
' 80 4800 0.61 0.11 524 527 -3
85 5100 0.61 0.11 556 617 -61
90 5400 0.61 0.11 589 707 -118
Storage = (Vol in. - Vol. out) ,
,
'
,
,
'
1
, Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA2-3.wb3
Date: 10/19/01 Page 4
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION. PHASE 1
Basin Name: DA-2 & DA-3 Design Frequency = 10YR
No. of Subareas• 0
~ 7. Determine the Minimum Required Depth Above "208" Swale.
' Required Detention Storage 333.5 CF (See Bowstring Method, maximum value)
"208" Swale Volume 330.0 CF
Required Storage Above "208" Swale 3.5 CF
, 208" Swale Top Width NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 9900 SF (See "208" Swale Volume Calculations)
"208" Swale Side Slopes (X 1) 4.0 ft (See "208" Swale Volume Calculations)
' Depth Above "208" Swale 0.10 ft ASSUMED
' Detention Pond Top Width NA ft
Detention Pond Top Length NA ft
Top of Detention Pond Area 990.0 SF
Volume Above "208" Swale 99.0 CF POND SIZE CHECKS
' 8. Determine Length of Curb Opening:
, Q = 0.56'(ZJn)'(S^1/2)'(d^8/3)
Flow, Q= 0.57 cfs Included Basin DAx Bypass
Slope, S = 0.009 Wft
' n = 0.014 Roughness Coefficient
Cross Slope,s= 0.01 ft/ft
Z =1/s = 100.00 ft!ft
' Flow Depth, d= 0.087 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC FLOW (CHECK)
a) Curb Openmg at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenY")
' Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 0.57 cfs
Flow Depth, d= 0 087 ft
Length of Opening = 2 R
' Use Q= 3.087(L)(H^3/2); Solve for H
Depth, H = 0.20 feet
' H/h = 0.41 O K- H/h =<1
lIUse 2 tt curb openlnq 11
,
,
1
'
1
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA4.wb3
Date: 10/19/01 Page 1
Name. SUMMERFIELD EAST SUBDIVISION
' Project. 4TH ADDITION, PHASE 1
Basin Name: DA-4 Design Frequency = 10YR
No. of Subareas: None
1
1. Determine Time of Concentra6on: ' Segment 1- Overland Fiow OVERLAND FLOW
Length, L= 74 ft(Length) MAX LENGTH= 300 ft.
' Slope,S = 0.01 fU ft (Slope)
n = 0.030 Roughness Coeffiaent (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Stormwater ManagemenY'.
' Tc1 = Ct'(L'n/(S^.5))^(0.6); From "Guidelines for Stortnwater ManagemenY'.
Tc1 = 0.96 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER
' Length, L = 0 ft
Slope,S = 0 005 fU ft
n = 0.014 Roughness Coefficient
, Depth, y= 0130 ft. (Assumed depth of flow)
Cross slope, s= 0 02 fUft
Z= 5000 fUft (Z= 1/s)
Area, A= 0.42 ft. (A= 1/2'(Z)"(Y"2)) '
' Q gutter = 0.57 cfs
Velocity,V = 1.36 ft/sec (V= Q/A)
' Tc2 = (Length)/(Velocity)
Tc2 = 0.00 min
Segment 3- Channel Flow NONE
' Length, L= 0 ft
Slope, So = 1 ft/ft
n = 0.012 Roughness Coefficient (Manning's)
Diameter = 0 inches
' Area, A= 0 000 sf
R= D/4 = 0 21 ft
Velocity, V= (1.49/n)'(R^213)'(So^1/2) (Mannings Equation)
' Velocity, V= 43.62 ft/sec .
Tc3 = (Length)!(Velocity)
Tc3 = 0 00 min
' Total Tc = 0 96 min
'
,
,
'
'
, Rational Method and Detention Basm Design VVyatt Engineering, Inc.
DA4.wb3
Date. 10/19/01 Page 2
Name: SUMMERFIELD EAST SUBDIVISION
, Project. 4TH ADDITION, PHASE 1
Basin Name: DA-4 Design Frequency = 10YR
No. of Subareas, None
' 2. Determine Weighted Runoff Coefficient (C) and Area. ' Area
Surface Type (sfl (acres) C. CA
Open land (2%-10% slope) 12,657 0.29 0.30 0 09
' Roof & Sidewalk 6,430 0.15 0.90 0.13
Asphalt, Curb & Dnveway 6,880 0.16 0.90 0.14
From Bypass DAx 0 0.00 0.98 0 00
' Total Drainage Area 25,967 0.60 acres Sum CA = 0 36
Total Impervious Treated Area 6,880 0.16 acres
' From Table 1, Page 6-2, "Gwdelines for Stormwater ManagemenY'
' Weighted C=(sum CA)/(sum A) = 0608
' 3. Determine Peak Runoff (Q=CIA):
Duration (Tc) = 0 96 min. ' Weighted C = 0.608
Intensity (I) = 3.18 in/hr From IDF curve for Spokane, WA
Area (A) = 0.60 acres
' Peak 10 YR Discharge (Q) = 1.15 cfs
4. Determine Volume of "208" Swale: ' Total Impervious Treated Area = 6,880 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 0 5712 m/ft
Required "208" Swale Volume = 287 cu. ft.
' 208" Swale Bottom Width 2.0 ft Irregular size - see site plan
"208" Swale Bottom Length 237.0 ft Ircegular size - see site plan
"208" Swale Depth 0.5 ft
' "208" Swale Side Slopes (X:1) 4.0 ft
"208" Swale Bottom Area 474.0 SF
"208" Swale Top Area 1422.0 SF Conservatrve Straight Wall
' "208" Swale Volume 474 CF POND SIZE CHECKS
,
'
,
'
'
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA4.wb3
Date. 10/19/01 Page 3
' Name: SUMMERFIELD EAST SUBDIVISION
Project: 4TH ADDITION, PHASE 1
Basin Name: DA-4 Design Frequency = 10YR
' No. of Subareas 0
5 Determine the Maximum Outflow (Qo).
, Number of Type "A" (0 3 cfs) Drywells Required: 1
Number of Type "B" (1.0 cfs) Drywells Required. 0
' Outflow (Qo) = 0.30 cfs (SEE ATfACHED CALCULATIONS)
6. Determine Reqwred DetenUon Storage Using Bowstnng Method
' Time Increment = 5 min.
Elapsed time Intens. Qin Vol. In Vol. Out Storage
' (min) (sec) (in/hr) (cfs) (cu.ft.) (cu.ft) (cu.ft)
0.96 57.8 3.18 1.15 89 0 89
' 0 0 3.18 1.15 0 0 0
5 300 3.18 1.15 368 0 368
10 600 2.24 0.81 503 5 498
15 900 1.77 0.64 590 48 541 '
' 20 1200 1.45 0.53 640 89 551
25 1500 121 0.44 666 126 540
30 1800 1.04 0.38 685 162 523
35 2100 0.91 0.33 699 199 500
' 40 2400 0.82 0 30 719 241 477
45 2700 0.74 0.27 729 279 449
50 3000 0 68 0.25 744 323 421
55 3300 0.64 0 23 769 377 393
' 60 3600 0.61 0.22 800 436 363
65 3900 0.61 0 22 866 526 340
70 4200 0.61 0.22 932 616 316
75 4500 0 61 0.22 998 706 292
, 80 4800 0.61 0 22 1065 796 268
85 5100 0.61 0 22 1131 886 245
90 5400 0.61 0.22 1197 976 221
Storage = (Vol in - Vol. out) .
,
,
,
,
'
'
, Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA4.wb3
Date: 10/19/01 Page 4
Name, SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-4 Design Frequency = 10YR
No of Subareas- 0
,
7. Determine the Minimum Required Depth Above "208" Swale•
, Required Detention Storage 551.3 CF (See Bowstring Method, maximum value)
"208" Swale Volume 4740 CF
Required Storage Above "208" Swale 77.3 CF
' 208" Swale Top Width NA ft (See "208" Swale Volume Calculabons)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculabons)
"208" Swale Top Area (SF) 1422.0 SF (See "208" Swale Volume Calculabons)
, "ZOS" Swale Side Slopes (X:1) 40 ft (See "208" Swale Volume Calculabons)
Depth Above "208" Swale 0.10 ft ASSUMED
, Detention Pond Top Width NA ft
Detention Pond Top Length NA ft
Top of Detention Pond Area 14220 SF
Volume Above "208" Swale 142.2 CF POND SIZE CHECKS
' 8. Determine Length of Curb Opernng•
, Q = 0 56`(ZJn) (S^1/2)`(d^8/3)
Flow, Q= 1 15 cfs Included Basin DAx Bypass
Slope, S = 0.005 ft/ft
' n = 0.014 Roughness Coefficient
Cross Slope,s= 0.01 ft/ft
Z =1 /s = 100.00 fUft
, Ffow Depth, d= 0.127 ft WITHIN 10°/a OF ASSUMED DEPTH FOR SHALLOW CONC. FLOW (CHECK)
a) Curb Opening at Low Point (See Page 640, "Guidelines for Stormwater ManagemenY")
' Curb Height (h)= 0.50 ft(Type 1 Curb Inlet) '
Discharge, Qn = 1.15 cfs
Flow Depth, d= 0.127 ft
Length of Opening = . 2 ft
, Use Q= 3.087(L)(H^312); Solve for H
Depth, H = 0.33 feet
' H/h = 0.65 O.K. - H/h =<1
l[Use 2 tt curb openinq 11
1
'
'
1
'
, Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA5-6.wb3
Date: 10119/01 Page 1
Name. SUMMERFIELD EAST SUBDIVISION
, Project: 4TH ADDITION, PHASE 1
Basin Name: DA-5 & DA-6 Design Frequency = 10YR
No. of Subareas- None .
.1
1. Determine Time of Concentration:
' Segment 1- Overland Flow OVERLAND FLOW
Length, L= 120 ft(Length) MAX LENGTH= 300 ft.
~ Slope,S = 0.01 ft/ ft (Slope)
n = 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Stormwater ManagemenY'.
' Tc1 = Ct'(L'n/(S^ 5))^(0.6); From "Guidelines for Stormwater ManagemenY'.
Tc1 = 1 29 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER
' Length, L = 0 ft
Slope,S = 0.005 ft/ ft
n = 0.014 Roughness Coefficient
' Depth, y= 0.120 ft. (Assumed depth of flow)
Cross slope, s= 0 02 ff/ft
Z = 50.00 ft/ft (Z= 1/s)
Area, A= 0.36 ft. (A= 1/2'(Z)'(y^2)) ' Q gutter = 0.46 cfs
Velocity,V = 1.28 fUsec (V= Q/A)
t Tc2 = (Length)/(Velouty)
Tc2 = 0.00 min
Segment 3- Channel Flow NONE
' Length, L= 0 ft
Slope, So = 1 ft/ft
n= 0 012 Roughness Coefficient (Manning's)
Diameter = 0 inches
, Area, A= 0 000 sf
R= D/4 = 0 21 ft
Velocity, V= (1 49/n)'(R112/3)'(So^1/2) (Mannings Equation)
' Velocity, V= 43.62 ff/sec _
Tc3 = (Length)!(Velocity)
Tc3 = 0.00 min
, Total Tc = 1.29 min
1
1
'
'
'
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA5-6.wb3
Date: 10/19/01 Page 2
Name: SUMMERFIELD EAST SUBOIVISION
t Project. 4TH ADDITION, PHASE 1
Basin Name- DA-5 & DA-6 Design Frequency = 10YR
No. of Subareas: None
'
2. Determine Weighted Runoff Coefficient (C) and Area:
' Area
Surface Type (sf) (acres) C. CA
' Open land (2°/a-10°/a slope) 13,112 0 30 0.30 0 09
Roof & Sidewalk 4,660 0.11 0.90 010
Asphalt, Curb 8 Driveway 6,780 0.16 0.90 0.14
From Bypass DAx 0 0.00 0.98 0 00
' Total Drainage Area 24,552 0.56 acres Sum CA = 0.33
Total Impervious Treated Area 6,780 0.16 acres
From Table 1, Page 6-2, "Guidelines for Stormwater ManagemenY'
Weighted C=(sum CA)/(sum A) = 0.580
' 3 Determine Peak Runoff (Q=CIA).
Duration (Tc) = 1.29 min.
' Weighted C = 0.580
Intensity (I) = 3.18 inlhr From IDF curve for Spokane, WA
Area (A) = 0 56 acres
' Peak 10 YR Discharge (Q) = 1.04 cfs
4. Determine Volume of "208" Swale:
' Total Impervious Treated Area = 6,780 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 0 5712 m/ft
Required "208" Swale Volume = 283 cu. k.
1 "208" Swale Bottom Width 2.0 ft Irregular size - see site plan
"208" Swale Bottom Length 194.0 ft Ircegular s¢e - see site plan
"208" Swale Depth 05 ft
' "208" Swale Side Slopes (X:1) 4.0 ft
"208" Swale Bottom Area 388.0 SF
"208" Swale Top Area 11640 SF Conservative Straight Wall
' "208" Swale Volume 388 CF POND SIZE CHECKS
'
'
1
1
1
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA5-6.wb3
Date: 10/19/01 Page 3
Name, SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-5 & DA-6 Design Frequency = 10YR
No. of Subareas: 0
'
5. Determme the Maximum Outflow (Qo):
' Number of Type "A" (0.3 cfs) Drywells Required- 0
Number of Type "B" (1.0 cfs) Drywells Required: 1
Outflow (Qo) = 1.00 cfs (SEE ATTACHED CALCULATIONS)
1
6. Determine Required Detention Storage Using Bowstring Method
' Time Increment = 5 mm.
Elapsed time Intens. Qin Vol In Vol. Out Storage
(min) (sec) (in/hr) (cfs) (cu.ft.) (cu.ftl (cu R)
' 1.29 77.3 3.18 1.04 108 0 108
' 0 0 3.18 1.04 0 0 0
5 300 3.18 104 339 0 339
10 600 2.24 0.73 458 70 389
15 900 1.77 0.58 536 229 307 '
' 20 1200 1.45 0.47 581 381 200
25 1500 1.21 0.40 603 518 85
30 1800 1.04 0 34 620 658 -37
35 2100 0 91 0.30 632 795 -163
, 40 2400 0.82 0.27 650 952 -302
45 2700 0.74 0.24 659 1095 -436
50 3000 0.68 0.22 672 1253 -581
55 3300 0.64 0.21 695 1444 -749
' 60 3600 0.61 0.20 723 1653 -930
65 3900 0 61 0.20 782 1953 -1170
70 4200 0.61 0.20 842 2253 -1411
75 4500 0.61 0.20 902 2553 -1651
' 80 4800 0.61 0.20 962 2853 -1891
85 5100 0.61 0.20 1021 3153 -2131
90 5400 0.61 0.20 1081 3453 -2372
Storage = (Vol in. - Vol. out)
1
1
'
,
1
' ,
, Rabonal Method and Detention Basin Design Wyatt Engmeering, Inc.
DAS-6 wb3
Date: 10/19/01 Page 4
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name. DA-5 & DA-6 Design Frequency = 10YR
No. of Subareas: 0
'
7. Determine the Minimum Required Depth Above "208" Swale:
1 Reqwred Detention Storage 388.5 CF (See Bowstring Method, maximum value)
"208" Swale Volume 3880 CF
Reqwred Storage Above "208" Swale 0.5 CF
' 208" Swale Top Width NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 11640 SF (See "208" Swale Volume Calculations)
' "208" Swale Side Slopes (X:1) 4.0 ft (See "208" Swale Volume Calculations)
Depth Above "208" Swale 0.10 ft ASSUMED
' Detention Pond Top Width NA ft
Detention Pond Top Length NA ft
Top of Detention Pond Area 1164.0 SF
Volume Above "208" Swale 116.4 CF POND SIZE CHECKS
, 8 Determine Length of Curb Opening:
' Q = 0 56*(ZJn)'(S^1/2)*(d^8!3)
Flow, Q= 1.04 cfs Included Basin DAx Bypass
Slope, S = 0.005 ft/ft
' n= 0 014 Roughness Coefficient
Cross Slope,s= 0.01 ft/ft
Z = 1 /s = 100.00 ft/ft
' Flow Depth, d= 0 122 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALIOW CONC. FLOW (CHECK)
a) Curb Opening at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenY")
' Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 1.04 cfs .
Flow Depth, d= 0 122 ft
Length of Opening = 2 ft
' Use Q= 3.087(L)(H^3/2), Solve far H
Depth, H = 0.30 feet
' H/h = 0.61 O.K. - H/h =<1
IIUse 2 tt curb opening
'
'
1
,
'
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA7 wb3
Date: 10119/01 Page 1
Name: SUMMERFIELD EAST SUBDIVISION
, Project: 4TH ADDITION, PHASE 1
Basin Name: DA-7 Design Frequency = 10YR
No. of Subareas: None
' 1. Determine Time of Concentration:
' Segment 1- Overland Flow OVERLAND FLOW
Length, L= 110 ft(Length) MAX LENGTH= 300 ft.
Slope,S = 0 012 ft/ ft(Slope)
1 n= 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Stormwater ManagemenY"
Tc1 = Ct'(L'n/(S^.5))"(0.6), From "Guidelines for Stormwater ManagemenY".
' Tc1 = 1.16 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER
, Length, L = 0 ft
Slope,S = 0 005 ft/ ft
n= 0 014 Roughness Coefficient
Depth, y= 0080 ft. (Assumed depth of flow) ,
' Cross slope, s= 0 02 ft/ft
Z= 5000 ff/ft (Z= 1/s)
Area, A= 0 16 ft. (A= 1!2"(Z)`(Y"2)) '
' Q gutter = 0.15 cfs
Velocity,V = 0 97 ft/sec (V= Q/A)
Tc2 = (Length)/(Velocity)
' Tc2 = 0.00 min
Segment 3- Channel Flow NONE
, Length, L= 0 ft
Slope, So = 1 ft/ft
n= 0 012 Roughness Coefficient (Manning's)
Diameter = 0 inches
' Area, A = 0.000 sf
R= D/4 = 0.21 ft
Velocity, V= (1.49/n)'(R^2/3)'(So^1/2) (Mannings Equation)
' Velocrty, V= 43.62 ft/sec
Tc3 = (Length)/(Velocity)
Tc3 = 0.00 min
' Total Tc = 1.16 min
'
1
'
1
'
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA7.wb3
Date: 10/19/01 Page 2
Name• SUMMERFIELD EAST SUBDIVISION
' Project 4TH ADDITION, PHASE 1
Basin Name: DA-7 Design Frequency = 10YR
' No. of Subareas. None
2 Determine Weighted Runoff Coefficient (C) and Area.
' Area
Surface Type M (acres) C. CA
, Open land (2%-10% slope) 4,322 0.10 0.30 0.03
Roof & Sidewalk 670 0.02 0 90 0.01
Asphalt, Curb & Dnveway 2,620 0.06 0.90 0 05
From Bypass DAx 0 0.00 0.98 0.00
' Total Drainage Area 7,612 0.17 acres Sum CA = 0.10
Total Impervious Treated Area 2,620 0.06 acres
From Table 1, Page 6-2, "Gwdelines for Stormwater ManagemenY"
Weighted C=(sum CA)/(sum A) = 0.559
' 3. Determine Peak Runoff (Q=CIA).
Duration (Tc) = 1.16 min. '
' Weighted C = 0.559
Intensity (I) = 3.18 in/hr From IDF curve for Spokane, WA
Area (A) = 0.17 acres
' Peak 10 YR Discharge (Q) = 0.31 cfs
4 Determine Volume of "208" Swale•
, Total Impervious Treated Area = 2,620 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 05712 in/ft
Reqwred "208" Swale Volume = 109 cu. ft.
' "208" Swale Bottom Width 2.0 ft Ircegular size - see site plan
"208" Swale Bottom Length 106.0 ft Irregular size - see site plan
"208" Swale Depth 05 ft
' "208" Swale Side Slopes (X,1) 4.0 ft
"208" Swale Bottom Area 2120 SF
"208" Swale Top Area 636.0 SF Conserva6ve Straight Wall
, "208" Swale Volume 212 CF POND SIZE CHECKS
'
,
1
'
'
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA7.wb3
Date, 10/19J01 Page 3
' Name: SUMMERFIELD EAST SUBDIVISION
Project: 4TH ADDITION, PHASE 1
Basin Name: DA-7 Design Frequency = 10YR
' No. of Subareas. 0
5. Detennine the Maximum Outflow (Qo):
' Number of Type "A" (0.3 cfs) Drywells Reqwred: 1
Number of Type "B" (1.0 cfs) Drywells Required: 0
' Outflow (Qo) = 0.30 cfs (SEE ATTACHED CALCULATIONS)
6. Determine Required Detention Storage Using Bowstring Method
' Time Increment = 5 min.
Elapsed time Intens. Qin Vol. In Vol. Out Storage
, (min) (sec) (in/hr) (cfs) (cu.ft) (cu.ft) (cu.ft)
1.16 69.4 318 0.31 29 0 29
' 0 0 3.18 031 0 0 0
5 300 3.18 0.31 101 0 101
10 600 2.24 0.22 137 0 137
15 900 1.77 0.17 160 0 160 '
' 20 1200 1.45 0.14 173 0 173
25 1500 1.21 0.12 180 0 180
30 1800 1 04 0.10 185 0 185
35 2100 0.91 0.09 189 0 189
' 40 2400 0.82 0.08 194 0 194
45 2700 0.74 0.07 197 0 197
50 3000 0.68 0.07 201 0 201
55 3300 0.64 0.06 208 0 208
' 60 3600 0.61 0.06 216 13 203
65 3900 0.61 0.06 234 103 131
70 4200 0.61 0.06 252 193 59
75 4500 0.61 0.06 270 283 -14
' 80 4800 0.61 0.06 288 373 -86
85 5100 0 61 0.06 305 463 -158
90 5400 0.61 0.06 323 553 -230
Storage = (Vol in. - Vol. out)
'
'
1
'
'
'
' Rational Method and Detention Basin Design Wyatt Engmeering, Inc.
DA7.wb3
, Date. 10/19/01 Page 4
Name• SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-7 Design Frequency = 10YR
No. of Subareas: 0
, 7 Determine the Minimum Required Depth Above "208" Swale.
' Required Detention Storage 207.9 CF (See Bowstnng Method, maximum value)
"208" Swale Volume 212.0 CF
Required Storage Above "208" Swale -4.1 CF
' 208" Swale Top Width NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 636.0 SF (See "208" Swale Volume Calculations)
"208" Swale Side Slopes (X:1) 4.0 ft (See "208" Swale Volume Calculations)
' Depth Above "208" Swale 010 ft ASSUMED
Detention Pond Top Width NA ft
t Detention Pond Top Length NA ft
Top of Detention Pond Area 636.0 SF
Volume Above "208" Swale 63.6 CF POP1D SIZE CHECKS
' 8. Determine Length of Curb Opening:
' Q = 0 56'(ZJn)'(S^1/2)'(d^813)
Flow, Q= 0.31 cfs Included Basin DAx Bypass
Slope, S = 0.005 ff/ft
' n= 0 014 Roughness Coefficient
Cross Slope,s= 0.01 fUft
Z= 1/s = 100 00 fUft
' Flow Depth, d= 0.078 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC. FLOW (CHECK)
a) Curb Opening at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenY")
, Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 0.31 cfs
Flow Depth, d= 0.078 ft
Length of Opening = 2 ft
' Use Q= 3 087(L)(H^3/2); Solve for H
Depth, H = 0.14 feet
, H/h = 0.27 O.K. - H/h =<1
lIUse 2 tt curb openin9 I1
1
'
'
'
' -
, Rational Method and Detention Basin Design Wyatt Engmeermg, Inc.
DA8.wb3
Date. 10l19/01 Page 1
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-8 Design Frequency = 10YR
' No. of Subareas. None
1. Determine Time of Concentration:
' Segment 1- Overiand Flow OVERLAND FLOW
Length, L= 190 ft(Length) MAX LENGTH= 300 ft.
' Slope,S = 1.4 ft/ ft (Slope)
n = 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Storrnwater ManagemenY".
' Tc1 = Ct'(L'N(S^ 5))^(0.6); From "Guidelines for Stormwater ManagemenP'
Tc1 = 0.39 min.
Segment 2- Shallow Concentrated Flow CURB GUTTER
, Length, L = 0 ft
Slope,S = 0.005 ftl ft
n = 0.014 Roughness Coefficient
' Depth, y= 0200 ft. (Assumed depth of flow)
Cross slope, s= 0 02 ft/ft
Z = 50.00 fUft (Z= 1/s)
Area, A= 1.00 ft. (A= 1/2'(Z)•(Y"2)) '
' Q gutter = 1.83 cfs ,
Velocity,V = 1.83 ft/sec (V= Q/A)
' Tc2 = (Length)/(VeloGty)
Tc2 = 0.00 min
Segment 3- Channel Flow NONE
' Length, L= 0 ft
Slope, So = 1 ft/R
n = 0.012 Roughness Coefficient (Manning's)
Diameter = 0 inches
' Area, A= 0 000 sf
R= D/4 = 0.21 ft
Velocity, V= (1 49/n)'(R^213)'(So^1/2) (Mannings Equation)
, Velocity, V= 43.62 ft/sec
Tc3 = (Length)I(Velocity)
Tc3 = 0.00 min
' Total Tc = 0.39 min
'
,
'
'
'
~ Rational MethQd and Deiention Basin Design Wystt Engineenng, Inc
DA8 wb3
Date' 40I19101 Page 2
~ Name; 5LINIMERFIELO EAST SUBDI1A1510N
Project 43H ApD1TIC}N, PHASE 1
Basin M1fame DA-8 Design Frequenc:y = 10YR
~ No ot Su6areas Nvne
2Determme Weighted Runvff Cvefficient [C] and Area.
~ Area
SurfBCe TYpe (sf) (aCres) C. CA
~ Open fand (2%-1096 sfvpe) 55,561 1 51 0.30 0 45
Roafi & Sidewalk 11,760 0 27 90 024
Asphalt, Curb & Ltnveway 23,910 0 55 090 0.49
Fmm Sypass DAx fl 0.60 0.98 0.00
~ Total erainage Rrea 101,231 2.32 acres 5um CA = 119
Total Impervious Treated Area 23,910 055 acres
From Tahle 1, F'aga 8-2, "Guidehnes for Stormwater NranagemenY'
wei9nted c= (sum cA)r(sum a) ~ 0.511
~ 3 Defermine Peak Ftunvff (Q=CIA)
Durafion {Tc} = 0 39 rnin
~ Weighted C = 0 511
lntensity (I) = 3 18 inlhr From 1C]F eurve far Spokane, WFI
Area [A) = 2 32 acres
~ Peak 10 YR Discharge (Q} = 378 cfs
4. Determme llaPume of "208" SwaEe.
~ Tatal Impervious Treated Area = 23,91 0 SF (Includes 0 ft2 bypass from QAx)
Required "248" Swale Vofume = Impervinus Area x q 5712 inlft
Required "208° Swale Volume = 986 cu tt
~ °208" Swale Bottam Width 2.0 ft Irregular sae - see site plan
"248" Swale Bottarn Length 891.0 R Irregular s¢e - see site plan
°208° Swale Depth a5 ft
~ "248" Swale Side 5lvpes (X:1) 40 ft
"208" Swale Bottvm Araa 17820 SF
"208" Swale Tvp Area 53460 SF Canservative Straight Wall
~ "2[]8" Swate Volume 1782 CF PONa 51ZE CHECICS
1
i
~
1
1
' RaUonal Method and Detention Basin Design Wyatt Engineering, Inc
DA8 wb3
Date: 10/19/01 Page 3
' Name: SUMMERFIELD EAST SUBDIVISION ,
Project: 4TH ADDITION, PHASE 1
Basin Name• DA-8 Design Frequency = 10YR
' No. of Subareas: 0
5. Determine the Maximum Outflow (Qo).
' Number of Type "A" (0.3 cfs) Drywells Reqwred: 0
Number of Type "B" (1.0 cfs) Drywells Reqwred: 1
Outflow (Qo) = 1.00 cfs (SEE ATTACHED CALCULATIONS)
'
6. Determine Required Detention Storage Using Bowstring Method
' Time Increment = 5 min.
Elapsed time Intens Qin Vol In Vol. Out Storage
' (min) (sec) (iNhr) (cfs) (cu.ft.) (cu.ft) (cu ft)
0 39 23.1 3.18 3.78 117 0 117
' 0 0 3.18 3.78 0 0 0
5 300 3.18 3 78 1164 0 1164
10 600 2.24 2.66 1618 0 1618
15 900 1.77 2.10 1910 53 1857 '
' 20 1200 145 1.72 2082 166 1916
25 1500 121 1.44 2168 261 1908
30 1800 1.04 1.24 2235 358 1876
35 2100 0.91 1.08 2280 452 1827
' 40 2400 0.82 0.97 2347 572 1775
45 2700 0.74 0.88 2382 674 1708
50 3000 0.68 0.81 2431 795 1636
55 3300 0.64 0.76 2516 957 1559
' 60 3600 0.61 0.72 2616 1142 1474
65 3900 0.61 0.72 2833 1442 1391
70 4200 0.61 0.72 3051 1742 1309
75 4500 0.61 -0.72 3268 2042 1226
' 80 4800 0 61 0.72 3486 2342 1144
85 5100 0.61 0.72 3703 2642 1061
90 5400 0.61 0 72 3921 2942 979
Storage = (Vol in. - Vol. out)
'
'
'
'
'
'
, Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA8.wb3
Date: 10/19l01 Page 4
, Name: SUMMERFIELD EAST SUBDIVISION
Project: 4TH ADDITION, PHASE 1
Basin Name: DA-8 Design Frequency = 10YR
' No. of Subareas: 0
7 Determine the Minimum Required Depth Above "208" Swale:
, Required Detention Storage 19156 CF (See Bowstring Method, maximum value)
"208" Swale Volume 17820 CF
Required Storage Above "208" Swale 133.6 CF
~ "208" Swale Top Width NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 5346.0 SF (See "208" Swale Volume Calculations)
' "208" Swale Side Slopes (X.1) 4.0 ft (See "208" Swale Volume Calculations)
Depth Above "208" Swale 0 10 ft ASSUMED
' Detention Pond Top Width NA ft
Detention Pond Top Length NA ft
Top of Detention Pond Area 5346.0 SF
Volume Above "208" Swale 5346 CF POND SIZE CHECKS
' 8. Determme Length of Curb Opening:
' Q = 0.56'(Z/n)'(S^1/2)'(d^8/3)
Flow, Q= 3.78 cfs Induded Basin DAx Bypass
Slope, S= 0 005 ft/ft
' n= 0 014 Roughness CoeffiGent Cross Slope,s= 0.01 R/ft
Z= 1/s = 100 00 ft/ft
' Flow Depth, d= 0.198 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC FLOW (CHECK)
a) Curb Opernng at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenY')
' Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 3.78 cfs
Flow Depth, d= 0 198 ft
Length of Opening = 4 ft
' Use Q= 3 087(L)(H^3/2); Solve for H
Depth, H = 0.45 feet
, H/h = 0.91 O.K. - H/h =<1
lIUse 4 ft curb opening
'
'
'
'
'
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA9.wb3
Date 10/19/01 Page 1
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-9 Design Frequency = 10YR.
' No. of Subareas: None
1. Determine Time of Concentration:
' Segment 1- Overland Flow OVERLAND FLOW
Length, L= 130 ft(Length) MAX LENGTH= 300 ft.
' Slope,S = 0.01 fU ft (Slope)
n = 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Guidelines for Stormwater Management".
t Tc1 = Ct'(L'n/(S^.5))^(0.6); From "Guidelines for Stormwater ManagemenY".
Tc1 = 1.35 mm.
Segment 2- Shallow ConcenVated Flow CURB GUTTER
' Length, L = 0 ft
Slope,S = 0 005 N ft
n = 0.014 Roughness Coefficient
' Depth, y= 0.200 ft. (Assumed depth of flow)
Cross slope, s= 0.02 fUft
Z = 50.00 ft/ft (Z= 1/s)
Area, A= 1 00 ft. (A= 1/2'(Z)"(y^2)) '
' Q gutter = 1.83 cfs
Velocity,V = 1 83 ft/sec (V= Q/A)
' Tc2 = (Length)/(Velocity)
Tc2 = 0 00 min
Segment 3- Channel Flow NONE
' Length, L= 0 ft
Slope, So = 1 ft/ft
n = 0.012 Roughness Coefficient (Manrnng's)
Diameter = 0 inches
' Area, A = 0.000 sf
R=D/4= 0.21 ft
Velocity, V= (1.49/n)'(R^2/3)'(So"1/2) (Mannings Equation)
' Velocity, V= 43.62 ff/sec
Tc3 = (Length)/(Velocity)
Tc3 = 0.00 min
' Total Tc = 1.35 min
1
1
'
'
'
' Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA9.wb3
Date: 10/19101 Page 2
' Name SUMMERFIELD EAST SUBDIVISION
Project 4TH ADDITION, PHASE 1
Basin Name. - DA-9 Design Frequency = 10YR
' No. of Subareas: None
2. Determine Weighted Runoff Coefficient (C) and Area. -
' Area
Surface Type (sf) (acres) C' CA
' Open land (2%-10% slope) 45,705 1.05 0.30 0.31
Roof & Sidewalk 21,940 0 50 0.90 0.45
Asphalt, Curb & Driveway 22,980 0.53 0 90 0.47
From Bypass DAx 0 0.00 0.98 0.00
' Totai Drainage Area 90,625 208 acres Sum CA = 1.24
Totai Impervious Treated Area 22,980 0.53 acres
From Table 1, Page 6-2, "Guideiines for Stormwater ManagemenY"
Weighted C=(sum CA)/(sum A) = 0.597
' 3. Determine Peak Runoff (Q=CIA):
Duration (Tc) = 1.35 min. ' Weighted C = 0.597
Intensity (I) = 3.18 iNhr From IDF curve for Spokane, WA
Area (A) = 2.08 acres
' Peak 10 YR Discharge (Q) = 3.95 cfs
4. Determine Volume of "208" Swale:
' Total Impervious Treated Area = 22,980 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 0.5"712 in/ft
Required "208" Swale Volume = 957 cu. ft.
' "208" Swale Bottom Width 2.0 ft Irregular size - see site plan
"208" Swale Bottom Length 658.0 ft Irregular size - see site plan
"208" Swale Depth 0.5 ft
' "208" Swale Side Slopes (X:1) 4.0 ft
"208" Swale Bottom Area 1316.0 SF
"208" Swale Top Area 3948.0 SF Conservative Straight Wall
' "208" Swale Volume 1316 CF POND SIZE CHECKS
1
'
'
'
1
' RaUonal Method and Detention Basin Design Wyatt Engineering, Inc
DA9.wb3
Date: 10/19/01 - Page 3
Name• SUMMERFIELD EAST SUBDIVISION
' Project 4TH ADDITION, PHASE 1
Basin Name: DA-9 Design Frequency = 10YR
' No, of Subareas. 0
5 Determine the Maximum Outflow (Qo):
' Number of Type "A" (0.3 cfs) Drywells Reqwred 1
Number of Type "B" (1.0 cfs) Drywelis Required. 1
' OutFlow (Qo) = 1.30 cfs (SEE ATTACHED CALCULATIONS)
6. Determine Required Detention Storage Using Bowstnng Method
' Time Increment = 5 min.
Elapsed time Intens. Qin Vol. In Vol Out Storage
' (min) (sec) (in/hr) (cfs) (cu.ft.) (cu ft) (cu.ft)
135 811 3.18 3.95 429 0 429
' 0 0 318 395 0 0 0
5 300 318 3.95 1295 0 1295
10 600 2 24 2 78 1747 165 1582
15 900 1.77 2 20 2041 392 1648
' 20 1200 1.45 1.80 2212 611 1602
25 1500 1.21 1.50 2297 812 1485
30 1800 1.04 129 2362 1016 1346
35 2100 0.91 1 13 2406 1217 1189
' 40 2400 0.82 1.02 2474 1441 1033
45 2700 0.74 0.92 2509 1650 859
50 3000 0.68 0.85 2559 1876 683
55 3300 0.64 0.80 2647 2139 508
' 60 3600 0.61 0.76 2750 2423 327
65 3900 0.61 0 76 2978 2813 164
70 4200 0.61 0.76 3205 3203 2
75 4500 0.61 0 76 3433 3593 -161
' 80 4800 0.61 0.76 3660 3983 -323
85 5100 0.61 0.76 3887 4373 -486
90 5400 0.61 0.76 4115 4763 -649
Storage = (Vol in. - Vol. out)
'
1
1
1
'
'
' Rational Method and Detention Basin Design Wyatt Engmeering, Inc.
DA9.wb3
Date: 10/19/01 Page 4
' Name. SUMMERFIELD EAST SUBDIVISION
Project: 4TH ADDITION, PHASE 1
Basm Name: DA-9 Design Frequency = 10YR
' No. of Subareas: 0
7. Determine the Mirnmum Required Depth Above "208" Swale:
' Required Detention Storage 1648.2 CF (See Bowstring Method, maximum value)
"208" Swale Volume 1316.0 CF
Required Storage Above "208" Swale 3322 CF
' "208" Swale Top Width NA R (See "208" Swale Volume Calculations)
"208" Swale Top Length NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Area (SF) 3948.0 SF (See "208" Swale Volume Calculations)
, "208" Swale Side Slopes (X:1) 4.0 ft (See "208" Swale Volume Calculations)
Depth Above "208" Swaie 0.10 ft ASSUMED
' Detention Pond Top Width NA ft
Detention Pond Top Length NA ft
Top of Detention Pond Area 3948.0 SF
Volume Above "208" Swale 3948 CF POND SIZE CHECKS
1 8 Determine Length of Curb Opening:
' Q = 0.56'(Zln)'(S^1/2)'(d^813) -
Flow, Q= 3.95 cfs Included Basin DAx Bypass
Slope, S = 0.005 ft/ft
' n = 0.014 Roughness Coefficient
Cross Siope,s= 0 01 ft!ft
Z = 1/s = 100.00 fUft
' Flow Depth, d= 0.202 ft WiTHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC FLOW (CHECK)
a) Curb Openmg at Low Point (See Page 6-40, "Guidelines for Starmwater ManagemenY')
' Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 3 95 cfs
Flow Depth, d= 0.202 ft
Length of Opening = 4 ft
' Use Q= 3.087(L)(1-1113/2), Solve for H
Depth , H = 0.47 feet
' H/h = 0.94 O K. - H/h =<1
liUse 4 ft curb opening 11
'
'
'
'
' '
, Rational Method and Detention Basin Design Wyatt Engineering, Inc.
DA10.wb3
Date: 10/19/01 Page 1
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name DA-10 Design Frequency = 10YR
No. of Subareas: None
'
1. Determine Time of ConcenVahon:
, Segment 1- Overland Flow OVERLAND FLOW
Length, L= 260 ft(Length) MAX LENGTH= 300 ft.
, Slope,S = 0.014 ft/ ft (Slope)
n = 0.030 Roughness Coefficient (Grass)
Ct = 0.15 From Figure 3, Page 6-5, "Gwdelines for Stormwater Management"
' Tc1 = Ct'(L'n/(S^.5))^(0.6); From "Guidelines for Stormwater ManagemenP'.
Tc1 = 1.85 min
Segment 2- Shallow Concentrated Flow CURB GUTTER
' Length, L = 0 ft
Slope,S = 0.005 ft/ ft
n = 0.014 Roughness Coefficient
' Depth, y= 0 170 ft. (Assumed depth of flow)
Cross slope, s= 0.02 ff/ft
Z = 50.00 ft/ft (Z= 1 /s)
Area, A= 0.72 ft. (A= 1/2'(Z)'(Y"2))
' Q gutter = 1.18 cfs
Velocity,V = 1.64 ft/sec (V= Q/A)
' Tc2 = (Length)/(Velocity)
Tc2 = 0.00 min
Segment 3- Channel Flow NONE
, Length, L= 0 ft
Slope, So = 1 fUft
n = 0.012 Roughness Coefficient (Manning's)
Diameter = 0 inches
' Area, A = 0.000 sf
R= D/4 = 0.21 ft
Veloaty, V= (1.49/n)`(R^2/3)'(So^1/2) (Mannings Equation)
' Veloaty, V= 43.62 fUsec
Tc3 = (Length)/(Velocity)
Tc3 = 0.00 min
' Total Tc = 1.85 min
'
'
'
'
,
Rational Method and Detention Basin Design Wyatt Engineering, Inc
DA10.wb3
Date• 10/19/01 Page 2
Name: SUMMERFIELD EAST SUBDIVISION
Project: 4TH ADDITION, PHASE 1
' Basin Name• DA-10 Design Frequency = 10YR
No. of Subareas: None
' 2. Determine Weighted Runoff Coefficient (C) and Area.
Area
' Surface Type (sfl (acres) C. CA
Open land (2%-10% slope) 43,318 0.99 0.30 0.30
Roof & Sidewalk 9,900 0.23 0.90 0.20
' Asphalt, Curb & Driveway 11,350 0.26 0.90 0 23
From Bypass DAx 0 0.00 0.98 0.00
Totaf Drainage Area 64,568 1.48 acres Sum CA = 0.74
' Total Impervious Treated Area 11,350 0 26 acres
' From Table 1, Page 6-2, "Guidelines for Stormwater ManagemenY'
' Weighted C=(sum CA)/(sum A) = 0.497
' 3. Determine Peak Runoff (Q=CIA).
Duration (Tc) = 1.85 min.
Weighted C = 0.497 •
Intensity (I) = 3.18 in/hr From IDF curve for Spokane, WA
' Area (A) = 1.48 ac,res
Peak 10 YR Discharge (Q) = 2.34 cfs
' 4. Determine Volume of "208" Swale:
' Total Impervious Treated Area = 11,350 SF (Includes 0 ft2 bypass from DAx)
Required "208" Swale Volume = Impervious Area x 0 5712 in/ft
Required "208" Swale Volume = 473 cu. ft.
' "208" Swale Bottom Width 2.0 ft Irregular size - see site plan
"208" Swale Bottom Length 375.0 ft Irregular size - see site plan
"208" Swale Depth 0.5 ft
"208" Swale Side Slopes (X:1) 40 ft
' "208" Swale Bottom Area 750.0 SF
208" Swale Top Area 22500 SF Conservative Straight Wall
"208" Swale Volume 750 CF POND SIZE CHECKS
'
,
1
'
' '
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc
DA10.wb3
Date: 10/19101 Page 3
Name- SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name: DA-10 Design Frequency = 10YR
No. of Subareas: 0
' 5. Determine the Maximum Outflow (Qo):
' Number of Type "A" (0.3 cfs) Drywells Required: 0
Number of Type "B" (1.0 cfs) Drywells Required: 1
Outflow (Qo) = 1.00 cfs (SEE ATTACHED CALCULATIONS)
'
6 Determine Required Detention Storage Using Bowstnng Method
' Time Increment = 5 min.
Elapsed time Intens Qin Vol. In Vol. Out Storage
' (min) (sec) (in/hr) (cfs) (cu.ft ) (cu.ft) (cu.ft)
1.85 111 1 318 2 34 349 0 349
' 0 0 3.18 2.34 0 0 0
5 300 3.18 2.34 792 0 792
10 600 2 24 1.65 1053 146 907
15 900 1.77 1.31 1224 325 899
' 20 1200 1.45 107 1323 499 825
25 1500 1.21 0.89 1372 659 713
30 1800 1.04 0.77 1409 822 587
35 2100 0.91 0 67 1434 982 452
' 40 2400 0.82 0 60 1474 1160 314
45 2700 0.74 0.55 1494 1326 168
50 3000 0.68 0.50 1523 1504 19
55 3300 0 64 0.47 1575 1711 -136
' 60 3600 0.61 0.45 1636 1933 -296
65 3900 0.61 0.45 1771 2233 -461
70 4200 0.61 0.45 1906 2533 -626
75 4500 0.61 0.45 2041 2833 -792
' 80 4800 0.61 0.45 2176 3133 -957
85 5100 0.61 0.45 2311 3433 -1122
90 5400 0.61 0.45 2446 3733 -1287
Storage = (Vol in. - Vol. out)
'
'
1
'
'
'
' Rational Method and Detention Basin Design Wyatt Engineenng, Inc.
DA10.wb3
Date• 10/19/01 Page 4
Name: SUMMERFIELD EAST SUBDIVISION
' Project: 4TH ADDITION, PHASE 1
Basin Name• DA-10 Design Frequency = 10YR
No. of Subareas. 0
' 7. Determine the Minimum Required Depth Above "208" Swale•
, Required Detention Storage 907.5 CF (See Bowstnng Method, maximum value)
"208" Swale Volume 750.0 CF
Required Storage Above "208" Swale 1575 CF
' 208" Swale Top Wdth NA ft (See "208" Swale Volume Calculations)
"208" Swale Top Length NA k (See "208" Swale Volume Catculahons)
"208" Swale Top Area (SF) 2250.0 SF (See "208" Swale Volume Calculations)
"208" Swale Side Slopes (X.1) 4.0 ft (See "208" Swale Volume Calculations)
' Depth Above "208" Swale 0.10 ft ASSUMED
Detention Pond Top Width NA ft
' Detention Pond Top Length NA ft
Top of Detention Pond Area 2250.0 SF
Volume Above "208" Swale 225.0 CF POND SIZE CHECKS
' 8. Determine Length of Curb Opening:
Q = 0.56'(Z/n)'(S^1/2)`(d^8/3)
, Flow, Q= 2 34 cfs Included Basin DAx Bypass
Slope, S = 0.005 fUft
n = 0.014 Roughness Coefficient
' Cross Slope,s= 0 01 ft!ft
Z= 1/s = 100 00 fUft
, Flow Depth, d= 0.166 ft WITHIN 10% OF ASSUMED DEPTH FOR SHALLOW CONC FLOW (CHECK)
a) Cufi Openmg at Low Point (See Page 6-40, "Guidelines for Stormwater ManagemenY')
, Curb Height (h)= 0.50 ft(Type 1 Curb Inlet)
Discharge, Qn = 2.34 cfs
Flow Depth, d= 0.166 ft
Length of Opemng = 4 ft
' Use Q= 3.087(L)(H^3/2); Solve for H
Depth, H = 0.33 feet
' H/h = 0 66 O K. - H/h =<1
IIUse 4 tt curb opening I1
'
'
'
'
1
,
' Summerfield East 4' Addition
Phase l Subdivision
,
,
~
' APPENDIX V - Miscellaneous Figures
'
'
'
'
,
,
'
'
'
,
'
' 02001. VJyatt Engineering (679300) StOtm Water Brief
October 19, 2001
'
~
~~i,~~ - ~ - - - ,-I- - -
_
- - - -
-
- - - - ~ -
- =-i----- - -T _
-
- ~ r' - --~1-
~ ` - !
- - ' - - - - ~
-
_ - - I - - - ~--1-
- - - _ - -
_ _ _ _-=1===-=
_ - _ -
AF -
- ( - - - - - - - - - -L.
-
_ - _ - -
_ - - - ' - -
- -
- - - -
- A _ - - ~ -
-r- -
~ _ _ _ - - - ~ - - - ~ _ _ _ -j° _ a ~y _ _ _ _ _ _ -
W I I--_'- fi - ~_L .
- - -
'3 ~ - - ---k---~~ ---1--- -
~ ~ - ' - - - - - - _ j=_ - ~ - -
- - ' - - ~ ---iT~•-i - - - -_l___.
J - -
- - - - - - - -
T, _ ~ - - - - , - -
Z _ - ~
- - -
N
VME
_
- - - - - - _-_-_-=-==--~a-__
, - - - - - _ -
- - - - - =
~ - ~ ~ - `
. ~ - -
- ~.~~~--___►=~====_l== - - - - - -__------1----~--_~
O /O _ 20 30 ~ 40 SO .60 70 80 90 /OD
- DRYWELL BARREI OR
. GENERAL NOTES WATERPROOF-,,' CATCN BASINPPE ~TYP.)
t. CRAVEL BACKFIIL QUANIITY FOR DRYYrELLS : NON-SHRINK f NOTE.
7YPE "A" - 30 CUBIC YAROS M4NIIAUM / 42 TONS. GROUT -
7YPE "B" - 40 CUBIC YAROS MINIMUM / 58 TONS PVC PlPE AOAPTERS ANU CASKET AIAY VARY
OR AS SPECIFIED OPl ROAO PUNS IN SHAPE AfVO 512E AS ILIUSTRATEO IN
DE7AIL BY ACCEPTA9lE ALTERNATE iN
2. SPECIAL BACKFIIL A1AlERIAL FOR ORYWELI.S SHAIL C014SIST OF ACCOROANCE VNTH A S.T M-C-428.
WASHED GRAVEI CRAOED FROM 1" TO J" WI7H A MAXIMUM OF SX PAS5117G TIIE U S No. 200 SCREEN, AS MEASUREO BY WEICHT. ~J GASKE7
A MAXIMUM OF IOX OF THE AGGRECATE, AS MEASUREO 8Y WEIGHT, ~ PVC AOAPTER
• MAY BE CRUSHED OR FRACTURED ROCK 7HE REMAININC 90%
SHALL 8E NAiURALLY OCCURRING UNFRACNRED IAATERIAL PVC ADAPTER
3 FABRIC SHALL 9E MOOERATE SURNVABIUTY AS OUTIiNED (SAIND COLLAR)
RJ S7AIJDARD SPECIFICATIONS 8-33
4 SEE STANDARO PLANS SHEETS B-2 AMD B-3 FOR
, PRECAST CONCRETE DETAILS. GRATE T1R'PAEE4~ MORTAR IN PIACE
5 AOJUST}AENT BLOCKS SHAU. BE CEMEhIT COr~CREiE pAY LIMITS
8 pRECAST RISER MAY BE USED IN COMBINATION METAL FRAME
K7i11 OR W UEU OF ADJUSTING BLOCKS k GRATE-\_. _
7. WHEN PVC PIPE IS USED A PVC ADAPIER SHALI 6E UJSTAt,IED.
B PIPES SfIALL BE CROUTED INTO ORYI4ELLS. TOP SOIL ~ rMORTARED ADJUSTIAENi
Rirics
CETAL ~RAME 4 TYPE 4 ~ A L BACKF ` I 2I-0'
RATE irrE ~
MORiAR IN PLACE TO E COFdPLETELY
o COVE ED W1iH FABRIC , I
ILL
N
lial -•,j ~-nILEr PiPe
. C z
TOP SOIL rADJAl1TSTMENT RIIIGS
~ GRAVEL BACKFILL O
TO BE COldPIEiEIY 2_0• m ~-g° C7 O O I` ''-SEE NOTE 7 0
~ COVEREO A9RIC mTM SEE CEN.
~ NOTE I k P.
' INLET PIPE ~ CFAVEL ,I L SEEPAGE POR15.
f BAGKFlLL, : ~SEE OETAII„ SHT. B-2.7
NOTE iNdc 2 FABRIC LINER
A~~ ~t. ~u rr ~ ; i o o i,
O SEE f 7
SEE DETAIIGESFIEET B-2 a :•I G.
FABRIC UNER
r~~ N
a
NDISiUR8EO
SOIL Q~4ISTURBED
DRYWELL - TYPE 'A' SWALE DR,YWELL - TYF'E 'B' SWALE
/i
SPOKANE COUNTY
APPROVED: s~tEe~t'
DEPARTMENT 0F PUBLIC WORKS STANDARD
NO.IDATE IAYiCK0-1APPR i tiE~fSfbF~ SPdNANE, wti 99108 ,x-~eoa oA~
PRECAST DRYWELLS PLACED IN SWALES 8-to
,
~ . _
'
,
'
Min, Berm elev
~ Top of Sod plus 1.0 ft
Top of curb (Tc) elev. Curb
\ 3 max.
- - 1 2" curb drop ~
grate elev ~ 13~
~
Top of Sod 4° concrete
Top of subgrade
' V
/7 -
drywell
~
Grassed Percolation A,rea (GPA) ~ i
Guidelines for Stozmwater Management ~
Addendum, February 1998
Fi ~Cov
~e 48 P; .6-84 S~ r~
' .
GENERAL NO7ES
1. CURB INLEi SHALL BE CONSTRUCiED IN ACCORDANCE
WI7H AST1J C 478 (AASHTO fA 199) k ASTIA C 840
UNlESS OTHERWISE SfIOWN ON PLANS OR NOiEp
IN TNE PROJECT SPEGAL PROVISIaNS
1 TOP SURFACE TO BE BROOM FINISHEO ,
3. ALL EXTERNAL EDCES NO7 LABELED SIIALI BE
TROWELLED V+STH I/i' RAp1US EDCER
4 OIAIENSION "l' SHAIL 6E SF{OVM ON iliE PLANS.
~(t DRAINAGE ~ CURB DROP_ _
SWALE
3'-J ~ DRAINAGE
SWALE
CURB AND . . . . ~ r
I -GUTTER 4 PORTLAND CEMENT i
CONCRETE
BY SECTiON B-B 3,- -"L.,-i~ 3'-
CURB INLET TYPE 1
.JN 4
` rto-nao.c
SPOKANE COUNTY APPROVEO: ' S~iEEr
- =
ur~ ,aN Jro~«< .
pJD-4~~~E~t~FfZ`IIRH-TtT-SiPACc I DEPARTMENT OF PUBLIC WORKS ca STANDARD
N01 ATF 1B- ~~fS~F SPOKANE. WA. 99206 ,sa-xoo oA CURB INLET TYPE 1 B-8
12"
~I
R-l,
~
--il 1/2' 24' ~ ~
2 3/4'--- --`-6" 2 3/4' i g~.. L~ 17'
v-% 18' i 4.
~
S/B' TYPE °M"
PAVEIAEN7 R-1
4~ OUANiITY - 0022633 C.Y. / LF.
~ .
~s' PORTLAND 'L~n
CEMENT 1O , .
~ CONCREiE . . , vARIES,
j i ASPHALT CONCAETE
TYPE "A" TYPE "8" TYPE "C" : 12"
, OUANTITY. - 0.036025 C Y./ LF. OUANTITY . 0047657 C Y / Lf. OUANTITY - 0 023123 TONS / L.F. '
SEE NOTE 6, SEE NOiE 8 ' -
TYPE "S"
OUANi1TY • 0.018519 C.Y. / L F.
GENERAL NOTES
I
~ 1. PORTLAND CEMENT CONCREiE SHALI BE
Q~ CLA55 1000 COPlFOR1AlNG SO ZHE SiANDARD
,~4. EXISTING CURB~ ~ ig- SPEdFICATIONS
m I , 2. WEAKfNEO PLANE JOtNTS i'OR POR7LAND
I ~~SIDEWALK CEMENT CONCREiE SHALL 8E PIACED AT i5'
p•~~'~,_ ~Z• INiERVALS.
I 3. 3/8' EXPANSION JOINTS IN PORiLM1D CEMENT
CONCRETE SNALL BE PLACED AT CURB REIURNS
1 3J8
~ 2~ 4. EPOI(Y CEMENT SHALL BE APPI.IEO AT A 10-15
R~12~
1• THICKNESS AND SHALL CONFORAI TO iHE
~ R~13"-•-~ REOUIRE►IENTS OF 5EG710N 9-26 OF THE
r . ► N4 ► / ~
EPOXY STANDARD SPEGFICA110N5.
L SEE NOTE 4 5 CONSTRUC110N OF 7YPE 'M' CURB SNALL CONFOfi►f
TO SECTION 8-04 OF THE ST/WDARD SPECIFICAilONS
L 1 11/I6/ ~ L- PORTIAND
CEMENT EXCEPT THAT PORIIAND CEMENT SHALL 8E REPLACED
m '3 1/2- OPilONA4 i0R CONCRETE M77H 'iRiwTY WFtITE' CEuENT. TT~E FwlSri SHALL 6E
PORTLAND INiEGRAL POUR STEEL iROWELLEO 10 PROVIOE A DENSE. 5►r001N
CEMENT CONCRETE CONCRETE GUTTER REFLEC71VE FINISFi,
TYPE "R,l OUANi1TY . 00444119 CY. / L,F. 6• TO BE USED ONLY lN SPEqAL CASES MATH APPROVAL
OF THE COUNTY ENCINEER.
' pUANT1TY - 0052259 C.Y / Li', 7. CURBS SFIALL MAYE A LICHT BROOAfED FINISM. +
i CUTTERS SHALL HE fIN15HED NATH A SiEEI 7ROWEL.
SPOKANE COUNTY APPROVED: o~~ - -STANDARD- sHEEI'
~[BI Gc. I NCH I '~,N" 01YEN90N ADDEQ TO CUFB SECTskl~ CWN N u
Sr+ 1 NCM 1 DltlEN4dJ COHNEC110N - IYPE -R' CURB 1 DEPAR7MENT Of PUBUC WORKS T~F E~ CURBS dc GUTTERS A-3
V If:Kfl IAPPR. 1 RFNSIf1N 1 w~• n~ 4se-3eoo oArt~r_~ • ~
f
ADDENDUM TO:
SUNIMERFIELD EAST, 4TH ADDITION, PHASE 1
RESIDENTIAL SUBDIVISION
STORM WATER
DESIGN BRIEF
Date: February 15, 2002
RE: Modifications to the Drainage Report to reflect comments from Spokane County, Development
Engineering Services. -
ModiFications •
Item #1: Add the following sentences to page Storm-7, paragraph 8, after the last sentence:
"The one foot interceptor berm and two type B drywells shall be constructed along the
north boundary of the plat to provide an additional factor of safety against flooding from
khe Zone B flood plain, as stipulated by Tammy Williams, Spokane County Flood Plain
Administrator. See letters from Tammy Williams and Dean Franz in Appendix V."
Item #2: Add the attached letters from Tammy Williams and Dean Franz to Appendix V.
-
T
S O U N Y
DNLSION OF ENGINEERING e1ND ROADS • A DIVISION OF THE PUBLIC WORKS DEPARTMENT
William A. johns, P.E., County Ezigineer Dennis M. Scott, P.E., Duector
July 6, 1999
Dean Franz
IPEC _
707 W 7~', Suite 200
Spokane, WA 99204
RE: Summerneld East 4`h and 5h Addition, PE-1206
Dear Dean,
I am in receipt of your letter dated 7/1/99 outlining the conditions for building within the Zone B
floodplain in the above noted development. The conditions outline what we agreed upon in the
field on 6i29/99, and clarify what has been discussed through previous correspondence. I befieve
the floodplain concerns will be adequately addressed if these conditions are adhered to.
- If you have questions, please let me know.
Sincerely,
VC~ p
Tammie Williams Floodplain Administrator .
cc: Ken Tupper, file
1026 W. Broadway Ave. ' Spokane. WA 99260-0I70 •(549) 456-3600 FAX. (509) 324-3478 '?'DD: (509) 324-3166
- •
' INLAND PACIFIC ENGiNEERING, lNC.
July 1, 1999
IPE Project: 99004 Tammie Williams -
Floodplain Administrator
Spokane County Public Works -
• 1026 W. Broadway Ave, 2"d Floor
Spokane, WA 99250-1070
Y2E: Summerfield East 4`h & 5t° Addition ,
(Spokane County No. PE-1206)
Dear Tammie: , .
Thank you for meeting with us at the proj ecf site a few days 'ago. Given the unusual conditions of
having an. `Alluvial Floodplain' impacting the area, this naturally creates the need for close
communication with Coun'ry engineering staff as this development embarks upon final design. We
have listed below our understanding o:f what was agreed upon duri.ng the field meeting_
• The living spaces for single-family housing within the FEN1A Zone B flood zone is subject
- to certain elevation reshictions, as follows: 1) the top of concxete foundation/wall shaLl be
no less than 24 inches above the top of curb of the frontage road; 2) no openinas (e.g. doors
and windows) will be allowed below the "min. elevation of concrete wall"; 3) the garage
slab sha1I be no less than 18 inches above the top of curb of the frontage road; and 4) the
living area cau extend 42 inches below the described top of concrete wall_ An exhibit
showing these di.mensions is enclosed for clarification, and is labeled "Housing Construction
in FEi'YIA Zone B Azea-" .
~ The finish grade of the proposed streets within this plat, (e.g. the remaining phases within
the FEMA Zone B area), is to be at or close to existing grade. The intent of this criteria is
to not have any of the internal streets significantly below existing grade.
• A one foot deep interceptor berm and two Type B drywells will be consmicted along the
north side of the Zone B area with the next phase of Summerfield East. While no flooding
of the area from the `Forker Draw' is expected or has ever been observed, (due to the
presence of highly permeable `valley gravels'), an interceptor berm will be constructed tv
provide an additional factor of safety against flooding. Maintenance access shall be provided
to this interceptor berm, the beun will be placed within an easement, and maintenance
responsibilities of said berm and drywe]ls will be assumed by the developer.
i 0
Letter to Tammie Williams (7-1-99)
Summerfield East (PE-1206)
page 2
~ -
If any of these items of understanding are different that what you understood, please call me and we
can promptly make the necessary adjustrnents.
Sincerely,
Tnland Pacific Engineering
~
Dean Franz, P.E.
Engineering Manager
enci: Exhibit -`Housing Construction m FEMA Zone B Area' (8 '/z" x 11
cc: Ken Tupper
Project file
99004.Ltr ofUnderstanding.;-I-99.wod
0
. , .
~
1
,
~ FRAME WALL
ROAD .
WlNDOVd aR
~ FFtAME WALL
COhiCRETE SLAB
I FQR GARAGE •
FIN~SH k~~Aq MIN. E#..EV. OF CO~tGRETE WA~.L "
GRAl7E AT QR ~
~ NEAR Ex15TIN G . ~ z
GRAaE
~ d-
TOP CURS
~
~ - LfVdNG AREA
• ;,r~,/~/ LQWES-T ELEV.
CONCRETE WALL ,~~j '
EJNBRUKEN
SCALE; NOT 7Q SCALE
r ~ INLANQ
PacIFiC SUMMERFIELa EAST 4TH ANa 5TM ADDlT1ON
~ENG1NEERING HpUS1NG CONSTRUCTION IhJ FEMA ZONE B AREA
707 IVnSt 7ih - 5ulte 200 (508) 458-5840 - DA7E: 5\30\99
~-98004-EKhl3 p
5noliano, WA 89204 FAX; (509) 458-6844 AEC wc
~