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1997, 10-02 Draft EIS Appendix A Stormwater Drainage AnaylisDraft Environmental Impact Statement MIRABEAU POINT COMPREHENSIVE PLAN AMENDMENT AND ZQNE RECLASSIFICATION APPENDIX A STORMWATER DRAINAGE ANALYSIS Lead Agency: SPOKANE COUNTY DIVISION OF BUILDING AND PLANNING Spokane, Washington Prepared by: RAMM ASSOCIATES, INc. Spokane, Washington October 2, 1997 RECEIVED OCT 0 '. 1997 SPOKANE COUNN ENGINEER STORMWATER/DRAINAGE ANALYSIS for MIRABEAU POINT Spokane County, Washington December, 1996 Prepared by: Inland Pacific Engineering Company 707 W 7th Avenue, Suite 200 Spokane, WA 99204 (509) 458 -6840 This report has been prepared by the staff of Inland Pacific Engineering Company under the direction of the undersigned professional engineer whose seal and signature appears hereon. Timothy A. Schwab, P.E. TABLE OF CONTENTS INTRODUCTION 1 PURPOSE 1 ANALYSIS METHODOLOGY 1 PROJECT DESCRIPTION 1 TOPGRAPHY 2 SOILS 3 DRAINAGE NARRATIVE 4 CONCLUSIONS AND RECOMMENATIONS 9 LIST OF TABLES Table 1 - Existing Conditions - 50 Year Storm 7 Table 2 - Future Conditions - 50 Year Storm 8 TECHNICAL APPENDIX Site Plan /Basin Map Flood Map SCS Soils Map Table of Existing 10, 50 and 100 Year Storm Flows Table of Future 10, 50 and 100 Year Storm Flows Calculations for Existing 50 Year Storm Flows Calculations for Future 50 Year Storm Flows Calculations for Typical "208 "IStormwater Basin STORMWATER/DRAINAGE ANALYSIS INTRODUCTION This stormwater /drainage analysis has been prepared as part of the technical appendix for the Mirabeau Point Environmental Impact Statement. During the scoping process for the EIS, stormwater /drainage issues were identified as requiring a special study. The entire Mirabeau Point Master Plan area consists of 236.8 acres. The project requires an amendment to the Spokane County Comprehensive Plan for 156.7 acres of the site from a Rural (RR -10) designation to Commercial and Urban (B-2/B-3) designations. Also required are zone reclassifications for 121.7 acres of this site to B -2 and B -3 zones. The site is located approximately one half mile east of Pines Road, south of the Spokane River and north of the future Indiana Avenue and the existing UPRR tracks encompassing the former site of the "Walk in the Wild Zoo ". The existing land is vacant except for a few buildings remaining from the zoo. Spokane River and the Centennial trail are located directly north and east of the site. PURPOSE The purpose of this analysis is to give a general description of the existing stormwater /drainage conditions, how they will be affected by the proposed project and the way that the stormwater will be handled to prevent any adverse impacts to the environment due to stormwater. Since this project consists of a combination of several potential improvements such as a YMCA, community center, business park, retail, residential, and not specific improvements, this report will be limited to descriptions on generally how the stormwater will be handled. During final design of each of the improvements, final construction drainage plans and details will be provided for the Spokane County plan acceptance process. ANALYSIS METHODOLOGY The Rational Method, which is recommended for drainage basins less than ten acres in size, will be used to determine the peak discharges and runoff volumes for onsite basins that fall within this size limit. All drainage basins larger than ten acres whether on site or off -site will use the SCS Method (TR -55) to determine peak discharge and runoff volumes. PROJECT DESCRIPTION The entire Mirabeau Point Master Plan project site consists of 236.8 acres. The site is located east of Pines Road, north of Indiana Avenue, west of the Spokane River and north of Union Pacific Railroad track in portions of Sections 3, 10, 11, Township 25 N., Range 44 E.. W.M. in Spokane County. Proposed uses of this area include public and private recreational, educational, Inland Pacific Engineering Company Page 1 Mirabeau Point Drainage Report the ground cover. There is a small pond in the southeast corner of this northern area adjacent to the rock outcrop. A portion of the area between the rock outcrop and Euclid Avenue drains to this pond. There are also some depressed areas against the rock outcrop that stormwater drains to and seeps into the ground. A portion of the area south of Euclid Avenue drains to a low area near the road. The area north of Euclid Avenue generally drains north and east toward the Spokane River. The central area is undeveloped land with extremely rocky ground or rock outcrops. This area rises 50 - 75 feet above the surrounding area. Slopes in this area reach 20% to 70 %. The land slopes away from the central part of this central area to the north and south and toward the Spokane river. Pine trees and shrubs are growing in this area in a natural state. There are some trails through this area as part of the former zoo. This area will remain essentially undeveloped with only the existing trails remaining. SOILS As can be seen from the accompanying soils map from the Spokane County Soils Survey as performed by the Soil Conservation Service (SCS), the site has the following types of soils and hydrologic soil classifications: GgA - Garrison gravelly loam, 0 - 5% slopes: Soils within this soil type are somewhat excessively drained gravelly or stoney soils. This soil has moderately rapid permeability. Hydrologic Soil Classification - B GgB - Garrison gravelly loam, 5 - 20% slopes: Soils within this soil type are somewhat excessively drained gravelly or stoney soils. This soil has moderately rapid permeability. Hydrologic Soil Classification - B GnB - Garrison very stony loam, 0 - 20% slopes: Soils within this soil type are somewhat excessively drained stoney soils. This soil has moderately rapid permeability. Hydrologic Soil Classification - B StC - Spokane very rocky complex, 0 - 30% slopes: This unit consists of between 50 - 80% of moderately shallow Spokane loam and the remainder consists of rock outcrops. Hydrologic Soil Classification - C SuE - Spokane extremely rocky complex, 20 - 70% slopes: This unit consists of between 20 -50% of moderately shallow Spokane loam and the remainder consists of rock outcrops. Hydrologic Soil Classification - C Garrison soils have been pre- approved for drywell use within Spokane County. The Spokane complexes have not been approved for drywell use in Spokane County. The area with this type of soil is very rocky with much of the area characterized by rock outcrops. Therefore drywells in this central site area are anticipated to not be appropriate except at the border fringes with the Garrison type soils. Inland Pacific Engineering Company Page 3 Mirabeau Point Drainage Report final design of the developed areas, care will be taken to ensure that stormwater flow from this area will be taken into account. Drainage Basin Characteristics and Analysis The project was divided into existing basins, "A" through "I ". Predeveloped and future flows and volumes were calculated for each basin. See attachment in the appendix showing the location of the drainage basins. The following is a description of each basin, the proposed uses for that basin and how the stormwater will be handled during the final design. Basin "A" This basin is the portion of the project located north of Euclid Avenue, approximately 35.5 acres. The land is currently vacant with a ground cover of grass and small trees /shrubs. This basin currently drains in sheet flow to the Spokane River. The proposed land use for this basin is for residential uses. Drywells and "208" swales will be used to ensure that the 50 year peak storm flows and volumes are not increased over existing conditions. Basin "B" This basin is located south of Euclid Avenue at the extreme west end of the project and is approximately 3.2 acres in size. The land is currently vacant with a ground cover of grass and weeds. This basin drains to a depression located just south of the project area that has no outlet. Stormwater seeps into the ground. The proposed land use for this basin is for an RV park. Drywells and "208" swales will be used to ensure that the 50 year peak storm flows and volumes are not increased over existing conditions. Basin "C" This basin is located south of Euclid Avenue and east of basin "B ". It is approximately 7.1 acres in size. The land is currently vacant with a ground cover of grass and weeds. As in basin "B ", this basin drains to a depression located just south of the project area that has no outlet. Stormwater seeps into the ground. The proposed land use for this basin is for an RV park and other commercial development. Drywells and "208" swales will be used to ensure that the 50 year peak storm flows and volumes are not increased over existing conditions. Basin "D" This basin is located between Basin "C" and the Spokane River south of Euclid Avenue. A portion of the rocky outcrop is included in this basin. It is approximately 27.9 acres in size. The land is currrently undeveloped except for a few zoo related buildings and fences. Grass and weeds are the ground cover in the flat area and trees and shrubs are the ground cover in the rocky outcrop area. This basin drains to a low point near Euclid Avenue. Most of the water appears to seep into the ground, however some stormwater may flow over the road during extreme flows. The proposed land use for this basin is for commercial development and an amphitheater. Drywells and "208" swales will be used to ensure that the 50 year peak storm flows and volumes are not increased over existing conditions. Basin "E" This basin is located adjacent to the Spokane River and south of, but not adjacent to Euclid Avenue. It is approximately 25.5 acres in size. This basin includes some grassy /pasture land, the pond, some rock outcrop area, and some area developed for the former zoo. This basin drains Inland Pacific Engineering Company Page 5 Mirabeau Point Drainage Report EXISTING CONDITIONS - 50 YEAR STORM MIRABEAU POINT - EXISTING CONDITIONS Basin Area Land Cover "CN" or aC" ( *) Flow (cfs) Volume _ (Ac. -Ft.) A 35.5 100% grass, weeds 61 2.2 0.50 B 3.2 100% grass, weeds 0.25 1.1 0.05 C 7.1 100% grass, weeds 0.25 2.1 0.11 D 27.9 50% grass, weeds 50% trees, rock 61 70 2.5 .59 E 25.5 30% grass, weeds 20% gravel 50% trees, rock 61 85 70 6.1 0.87 F 34.0 50% grass, weeds 50% trees, rock 61 70 4.5 0.81 G 1.6 100% grass, weeds 0.25 0.5 0.03 H 35.6 100% grass, weeds 61 2.2 0.51 I 80.6 100% grass, weeds 61 4.0 1.11 ( *) "CN" values range from 0 to 100 with 100 being totally impervious. "C" values range from 0.00 to 1.00 with 1.00 being totally impervious. A "CN" value of 61 was used for the land cover labeled as grass and weeds in the table. This ground was all in the Garrison soil type area and therefore has a hydrologic soil classification of B. The ground cover is an old pasture or range land in good condition. From Spokane County Stormwater Guidelines manual, Table 5, the "CN" value is 61. A "CN" value of 70 was used for the land cover labeled as trees and rock in the table. This ground was all in the Spokane Complex soil type area and therefore has a hydrologic soil classification of C. The ground cover is wood or forest land with good cover. From Spokane County Stormwater Guidelines manual, Table 5, the "CN" value is 70. A "CN" value of 85 was used for the land cover labeled as gravel in the table. This ground was all in the Garrison soil type area and therefore has a hydrologic soil classification of B. From Spokane County Stormwater Guidelines manual, Table 5, for streets and roads under the gravel category, the "CN" value is 85. A "C" value of 0.25 was used for the land cover labeled as grass and weeds in the table for those basins less than 10 acres in size. This is based on the existing ground cover acting the same as the Inland Pacific Engineering Company Page 7 Mirabeau Point Drainage Report category "grass shoulders" in Table 1, Runoff Coefficients for storm sewers for either flat, rolling or hilly slopes. While there is significant amount of grass in the existing ground cover, it does not act as a lawn ( "C" = 0.15) nor does it act as cultivated land ( "C" = 0.30) since the ground is not currently farmed, but something in between. The category "grass shoulders" best fits the existing conditions. FUTURE CONDITIONS - 50 YEAR STORM MIRABEAU POINT - FUTURE CONDITIONS Basin Area Land Cover "CN" or "C" Flow (cfs) Volume (Ac.-Ft) A 35.5 Residential 75 15.0 1.87 B 3.2 RV Park 0.80 11.3 0.08 C 7.1 RV Park 0.80 19.3 0.23 D 27.9 Amphitheater 92 11.0 1.74 Rocky, Trees 70 E 25.5 Commercial Develop. 92 12.0 1.39 Rocky, Trees 70 Gravel Area 85 F 34.0 Community Complex 92 14.0 1.82 Open Space 61 Rocky, Trees 70 G 1.6 Community Complex 0.80 5.8 0.04 H 35.6 Ice Arena, Develop. 92 28.0 2.74 Open Space, Recreate 61 I 80.6 Hotel, Business Park 92 70.0 5.04 Open Space, Recreate 61 The same "CN" values were used for those areas with the same land cover. A "CN" value of 75 was used for the land cover labeled as residential in the table. This ground was all in the Garrison soil type area and therefore has a hydrologic soil classification of B. Lot sizes were assumed to be a quarter acre in size. From Spokane County Stormwater Guidelines manual, Table 5, the "CN" value is 75. For the amphitheater, the commercial development area, the community complex area, the ice arena, the hotel and the business park a "CN" value of 92 was used. All the ground in these areas of development have Garrison soil types and therefore have a hydrologic soil classification of B. From Spokane County Stormwater Guidelines manual, Table 5, the CN value for commercial and business Inland Pacific Engineering Company Page 8 Mirabeau Point Drainage Report area is 92. This assumes 85% of the land is impervious in the developed condition. In these areas, the "CN" was modified for anticipated open space and lawn uses. The area labeled as open space and recreation has a "CN" value of 61. All the ground in these areas have Garrison soil types and therefore have a hydrologic soil classification of B. From Spokane County Stormwater Guidelines manual, Table 5, the CN value for open space area is 61. This assumes grass cover on 75% or more of the area. For those areas less than 10 acres in size being developed to a RV park and a community complex, a "C" value of 0.80 was used. This was based on approximately 85% of the area being impervious with a "C" value of 0.90 and approximately 15% of the area in lawn with a "C" value of 0.15. v CONCLUSIONS AND MENDA TIONS Storm water ff from this project will be adequately handled to prevent any adverse impacts to the enyiro t. The quality of the storm water will be maintained through the use of "208 swales". The uantity of storm water runoff will be minimized to ensure that the runoff for 50 year storms wil of ecreased with the development through the use of drywells, swales and retention basins. Facilities for the final basins will be sized and designed by county standards. Typically the project will be developed in five to ten acre parcels. For purposes of demonstrating that adequate drainage facilities can be constructed to contain the 50 year storm, a bowstring analysis of a typical five acre parcel was performed. A time of concentration of 5 minutes was assumed as a worst case. Of the land cover, 25% was assumed to be open space or lawn, 25% to be building footprint, and 50% to be road and parking areas. It was determined that a basin or combination of basins with a volume of approximately 6,800 cubic feet with three drywells would be adequate to handle the stormwater. For a copy of these calculations, see the appendix. Inland Pacific Engineering Company Page 9 Mirabeau Point Drainage Report blaSTEIA PitAH DRAINAGE BASINS DIRECTION OF FLOW BASIN SUM MARY BASIN TOTAL AREA (ACRES) A 35.5 ACRES 3.2 ACRES C 7.1 ACRES D 27.9 ACRES E 25.5 ACRES F 34.0 ACRES G 1.6 ACRES H 35.6 ACRES I 80.6 ACRES ll' ,off teit. ZONE A• 11 / EUCLID ll FLOOD MAP ..w 3 ROAD 2 4 PROJECT LOCATION SHANNON ROAD f/ // /// // /// / /// // / /// i // / / '"i // MISSION AVENUE J IL �/1 /��v ��� • 1 V � TABLE OF EXISTING 10, 50 AND 100 YEAR STORM FLOWS EXISTING 10, 50 AND 100 STORM FLOWS EXISTING FLOWS (efs) Basin Area 10 Year 1 50 Year 100 Year A 35.5 0.9 2.2 4.2 B 3.2 0.8 1.1 1.3 C 7.1 1.5 2.1 2.4 D 27.9 1.1 2.5 5.0 E 25.5 2.8 6.1 10.4 F 34.0 1.8 4.5 8.6 G 1.6 0.4 0.5 0.6 H 35.6 0.9 2.2 4.2 I 80.6 1.6 4.0 7.8 TABLE OF FUTURE 10, 50 AND 100 YEAR STORM FLOWS FUTURE 10, 50 AND 100 STORM FLOWS FUTURE FLOWS (cfs) Basin Area 10 Year I 50 Year 100 Year A 35.5 9 15 21 B 3.2 9 13 14 C 7.1 15 22 24 D 27.9 10 14 20 E 25.5 10 16 22 F 34.0 8 14 20 G 1.6 5 7 8 H 35.6 18 28 36 I 80.6 50 70 90 CALCULATIONS FOR EXISTING 50 YEAR STORM FLOWS Quick TR -55 Version 5 46 S/N Return Frequency TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Page 1 50 years Executed 11 -18 -1996 11 35 59 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE A MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE A HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 10 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip 1 Runoff Ia /p Description (acres) (hrs) (hrs) (in) (in) input /used Grass area 355 00 61 0 0 50 0 00 2 40 I 0 17 153 50 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 355 00 acres or 0 5547 sq mi Peak discharge = 22 cfs >>» Computer Modifications of Input Parameters ««< Input Values Rounded Values Ia /p Subarea Tc * Tt Tc * Tt Interpolated Ia /p Description (hr) (hr) (hr) (hr) (Yes /No) Messages Grass area 0 45 0 00 0 50 0 00 No Computed Ia /p > 5 * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 35 59 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE A MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE A HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 10 used in area calculations) >>» Summary of Subarea Times to Peak «« Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) Subarea Grass area Composite Watershed 22 12 6 22 12 6 1 Quick TR -55 Version 5 46 S/N Page 3 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 35 59 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE A MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE A HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Grass area 0 0 0 0 0 0 2 8 16 Total (cfs) 0 0 0 0 0 0 2 8 16 Subarea 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 Description hr hr hr hr hr hr hr hr hr Grass area 20 22 19 17 14 11 10 9 8 Total (cfs) 20 22 19 17 14 11 10 9 8 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Grass area 7 7 6 6 5 5 4 4 4 Total (cfs) 7 7 6 6 5 5 4 4 4 Subarea 18 0 19 0 20 0 22 0 26 0 Description hr hr hr hr hr Grass area 4 3 3 3 0 Total (cfs) 4 3 3 3 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 35 59 Watershed file - -> J \DOCUMENT\96149\TR55\PRE A MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE A HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 0 12 1 0 12 2 2 12 3 8 12 4 16 12 5 20 12 6 22 12 7 19 12 8 17 12 9 16 13 0 14 13 1 12 13 2 11 13 3 10 13 4 10 13 5 10 13 6 9 13 7 8 13 8 8 13 9 8 14 0 7 14 1 7 14 2 7 14 3 7 14 4 7 14 5 6 14 6 6 14 7 6 14 8 6 14 9 6 15 0 6 15 1 6 15 2 6 15 3 5 15 4 5 15 5 5 15 6 5 15 7 5 15 8 5 15 9 5 16 0 5 16 1 5 16 2 5 16 3 4 16 4 4 16 5 4 16 6 4 16 7 4 16 8 4 16 9 4 17 0 4 17 1 4 17 2 4 17 3 4 17 4 4 17 5 4 17 6 4 17 7 4 17 8 4 17 9 4 18 0 4 18 1 4 18 2 4 18 3 4 18 4 4 18 5 4 0 NO BEFORE THE BOARD OF COUNTY COMNIISSIONERS OF SPOKANE COUNTY WASHINGTON IN THE MATTER OF AUTHORIZING THE EXECUTION OF DOCUMENTS IN CONJUNCTION WITH THE MIRABEAU POINT PROJECT RESOLUTION WHEREAS, pursuant to the provisions of RCW Section 36 32 120(6), the Board of County Commissioners of Spokane County has the care of County property and the management of County funds and business and WHEREAS, pursuant to the provisions of RCW Section 36 68 090 any county acting through its board of county commissioners is empowered to build, construct care for control supervise, improve operate and maintain parks playgrounds, gymnasium, and other recreational facilities, and WHEREAS, pursuant to the provisions of RCW Section 36 68 010 counties may establish park and playground systems for public recreational purposes and for such purposes shall have the power to acquire lands buildings and other facilities by gift, purchase, lease devise, bequest and condemnation, and WIUEREAS pursuant to the provisions of chapter 82 46 RCW, the Board of County Commissioners of Spokane County may use revenues generated from the real estate excise tax imposed thereunder for the financing of capital project(s) specified in a capital facilities plan element of a comprehensive plan, the terminology capital project(s) including, but not limited to public works projects of a local government for planning acquisition, construction, reconstruction, repair, replacement, rehabilitation or improvement of streets roads highways domestic water systems storm and sanitary sewer systems and parks and WHEREAS Mirabeau Point Inc a non -profit corporation, has advised the Board of County Commissioners that it is desirous of donating to Spokane County certain properties m conjunction with its project known as the Mirabeau Point subject to the county s contributing 1 million dollars from real estate excise taxes collected under chapter 82 45 RCW for certain capital projects NOW, THEREFORE, BE IT HEREBY RESOLVED by the Board of County Commissioners of Spokane County that the Board does hereby make the following commitment to the Mirabeau Point Inc a non -profit corporation in conjunction with project commonly referred to as Mirabeau Point PAGE 1 MTRABEAU POINT, INC 'S OBLIGATION 1 Donate or cause to be donated in fee simple all necessary road nght of -way as the Spokane County Engineer shall deem necessary at his sole option in conjunction with the Mirabeau Point Provided however the County shall coordinate the location of road right -of -way with the YMCA of the Inland Northwest 2 Donate or cause to be donated in fee simple a site subject to the sole approval of a majonty of the Board of County Commissioners of Spokane County compnsing between five (5) and eight (8) acres and located within the boundanes of the Mirabeau Point for a park 3 Donate or cause to be donated in fee simple a site subject to the sole approval of a majonty of the Board of County Commissioners of Spokane County, compnsing a minimum of 2 75 acres and located within the boundaries of the Mirabeau Point Project for a senior citizen center 4 Establish an association or other public body to assume all maintenance and operation responsibilities of the donated properties referenced in item No 2 hereinabove It is the intent of the County that the responsibility for maintenance and operation of the dedicated park will not paid for out of the County's general fund Mirabeau Point, Inc shall be responsible for advising all purchasers of property within the Mirabeau Point of this condition 5 Execute documents agreeing that all properties within the Mirabeau Point, not owned by non profit corporations will participate financially based upon a traffic study or excess capacity in the case of sarutary sewer systems in any capital improvements made by the County under the terms of this resolution to the extent that the capital improvements are m excess of those necessary to serve county properties Mirabeau Point Inc shall be responsible for advising all purchasers of property within the Mirabeau Point of this condition SPOKANE COUNTY'S OBLIGATIONS Subject to the above five (5)conditions and the YMCA filing a valid and fully complete building permit application for a facility on the Mirabeau Point Spokane County agrees to provide up to 1 million dollars from the real estate excise tax collected under chapter 82 45 RCW for the purpose of capital projects namely improvement of streets roads and highways as well as sanitary sewer systems to support the properties referred in items No 2 and 3 hereinabove The County s contnbution will be reduced to $700,000 00 in the event the Transportation Improvement Board approves 1998 funding for a full build -out road section as descnbed, along with the sanitary sewer systems, m correspondence dated November 27, 1996, attached hereto In the event that the capital projects discussed herein are PAGE 2 not included with the County s Capital Facilities Element of its Comprehensive Plan, the County agrees to process appropnate documents to include such capital projects in its Comprehensive Plan The County s commitment herein is not to be considered to vest the Mirabeau Point with any development rights under any land use regulations BE IT FURTHER RESOLVED by the Board of County Commissioners of Spokane County that either the Chairman of the Board or a majonty of the Board be and is hereby authorized to execute at other than an open meeting any and all necessary documents, as approved to form by the Spokane County Prosecuting Attorney's Office, consistent with the provisions of this resolution BE IT FURTHER RESOLVED by the Board of County Commissioners of Spokane County that the Spokane County Engineer be and is hereby authonzed to file appropnate applications with the Washington State Transportation Improvement Board to obtain 1998 funding for participation in the roadway improvements to the Mirabeau Point as described in the correspondence dated November 27 1996 attached hereto PASSED AND ADOPTED this /7 day of ATTEST WILLIAM E Clerk of th By BOARD OF COUNTY COMMISSIONERS OF SPO • C p : Y WASHINGTON PHILLIP D HARRIS Chairman 1 NAHUE, d SANNE MONTAGUE Deputy PAGE 3 VE HASSON (RESIMIRABEAU WE) Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 35 59 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE A MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE A HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 3 18 7 3 18 8 3 18 9 3 19 0 3 19 1 3 19 2 3 19 3 3 19 4 3 19 5 3 19 6 3 19 7 3 19 8 3 19 9 3 20 0 3 20 1 3 20 2 3 20 3 3 20 4 3 20 5 3 20 6 3 20 7 3 20 8 3 20 9 3 21 0 3 21 1 3 21 2 3 21 3 3 21 4 3 21 5 3 21 6 3 21 7 3 21 8 3 21 9 3 22 0 3 22 1 3 22 2 3 22 3 3 22 4 3 22 5 3 22 6 3 22 7 2 22 8 2 22 9 2 23 0 2 23 1 2 23 2 2 23 3 2 23 4 2 23 5 2 23 6 2 23 7 2 23 8 2 23 9 2 24 0 2 24 1 1 24 2 1 24 3 1 24 4 1 24 5 1 24 6 1 24 7 1 24 8 1 24 9 1 25 0 1 25 1 1 25 2 1 25 3 1 25 4 0 25 5 0 25 6 0 25 7 0 25 8 0 25 9 0 POND -2 Version 5 17 S/N Executed 11 -18 -1996 11 36 57 >>>>»» Summary of Hydrograph Volume « ««« Hydrograph 3 \document \96149 \tr55 \PRE A HYD Volume = 219,240 cu ft 5 03 ac -ft Quick TR -55 Ver 5 46 S/N Executed 16 22 46 11 -14 -1996 j \document \96149 \tr55 \PRE B TCT Mirabeau Point Storm Drainage Report Basin "B" (Factor of 10 used in area calculations) Tc COMPUTATIONS FOR Subarea #1 SHEET FLOW (Applicable to Tc only) Segment ID 1 Surface description grass Manning's roughness coeff , n 0 1500 Flow length, L (total < or = 300) ft 150 0 Two -yr 24 -hr rainfall, P2 in 1 300 Land slope, s ft /ft 0 0100 0 8 007 * (n *L) T 0 5 P2 * s 0 4 hrs 0 47 = 0 47 SHALLOW CONCENTRATED FLOW Segment ID 1 Surface (paved or unpaved) , Unpaved Flow length, L ft 450 0 Watercourse slope, s ft /ft 0 0200 0 5 Avg V = Csf * (s) where Unpaved Csf = 16 1345 Paved Csf = 20 3282 T = L / (3600 *V) ft /s 2 2818 hrs 0 05 = 0 05 CHANNEL FLOW Segment ID Cross Sectional Flow Area, a sq ft 0 00 Wetted perimeter, Pw ft 0 00 Hydraulic radius, r = a /Pw ft 0 000 Channel slope, s ft /ft 0 0000 Manning's roughness coeff , n 0 0000 V = 2/3 1/2 1 49 * r * s n Flow length, L T = L / (3600 *V) ft /s 0 0000 ft 0 hrs 0 00 = 0 00 TOTAL TIME (hrs) 0 52 Quick TR -55 Ver 5 46 S/N Executed 10 07 31 11 -18 -1996 j \document \96149 \tr55 \PRE C TCT Mirabeau Point Storm Drainage Report Basin "C" (Factor of 10 used in area calculations) Tc COMPUTATIONS FOR SHEET FLOW (Applicable to Tc only) Segment ID 1 Surface description grass Manning's roughness coeff , n 0 1500 Flow length, L (total < or = 300) ft 150 0 Two -yr 24 -hr rainfall, P2 in 1 300 Land slope, s ft /ft 0 0100 0 8 007 * (n *L) T 0 5 0 4 P2 * s hrs 0 47 = 0 47 SHALLOW CONCENTRATED FLOW Segment ID 1 Surface (paved or unpaved) 7 Unpaved Flow length, L ft 1050 0 Watercourse slope, s ft /ft 0 0100 0 5 Avg V = Csf * (s) where Unpaved Csf = 16 1345 Paved Csf = 20 3282 T = L / (3600 *V) ft /s 1 6135 hrs 0 18 = 0 18 CHANNEL FLOW Segment ID Cross Sectional Flow Area, a sq ft 0 00 Wetted perimeter, Pw ft 0 00 Hydraulic radius, r = a /Pw ft 0 000 Channel slope, s ft /ft 0 0000 Manning's roughness coeff , n 0 0000 V = 2/3 1/2 1 49 * r * s n Flow length, L T = L / (3600 *V) ft /s 0 0000 ft 0 hrs 0 00 = 0 00 TOTAL TIME (hrs) 0 65 Quick TR -55 Ver 5 46 S/N Executed 10 07 31 11 -18 -1996 3 \document \96149 \tr55 \PRE C TCT SUMMARY SHEET FOR Tc or Tt COMPUTATIONS (Solved for Time using TR -55 Methods) Mirabeau Point Storm Drainage Report Basin "C" (Factor of 10 used in area calculations) Subarea descr Tc or Tt Time (hrs) Tc 0 65 Quick TR -55 Version 5 46 S/N Page 1 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 30 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE D MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE D HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 10 used in area calculations) »» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip I Runoff Ia /p Description (acres) (hrs) (hrs) (in) (in) input /used Basin "D" 279 00 65 0 0 75 0 00 2 40 ( 0 26 I 45 45 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 279 00 acres or 0 4359 sq mi Peak discharge = 25 cfs >>» Computer Modifications of Input Parameters ««< Input Values Rounded Values Ia /p Subarea Tc * Tt Tc * Tt Interpolated Ia /p Description (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "D" 0 67 0 00 0 75 0 00 Yes * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 30 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE D MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE D HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 10 used in area calculations) >>» Summary of Subarea Times to Subarea Basin "D" Composite Watershed Peak Discharge at Composite Outfall (cfs) 25 25 Peak «« Time to Peak at Composite Outfall (hrs) 12 8 12 8 Quick TR -55 Version 5 46 S/N Page 3 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 30 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE D MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE D HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Basin "D" 0 0 0 0 0 0 1 4 9 Total (cfs) 0 0 0 0 0 0 1 4 9 Subarea Description Basin "D" Total (cfs) 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 hr hr hr hr hr hr hr hr hr 15 21 24 25 21 18 15 12 11 15 21 24 25 21 18 15 12 11 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Basin "D" 10 9 8 7 6 6 5 5 4 Total (cfs) 10 9 8 7 6 6 5 5 4 Subarea 18 0 19 0 20 0 22 0 26 0 Description hr hr hr hr hr Basin "D" 4 4 3 3 0 Total (cfs) 4 4 3 3 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 30 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE D MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE D HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 0 12 1 0 12 2 1 12 3 4 12 4 9 12 5 15 12 6 21 12 7 24 12 8 25 12 9 23 13 0 21 13 1 20 13 2 18 13 3 16 13 4 15 13 5 14 13 6 12 13 7 12 13 8 11 13 9 10 14 0 10 14 1 10 14 2 9 14 3 9 14 4 9 14 5 8 14 8 8 14 9 7 15 0 7 15 1 7 15 2 7 15 3 6 15 4 6 15 5 6 15 6 6 15 7 6 15 8 6 15 9 6 16 0 6 16 1 6 16 2 6 16 3 5 16 4 5 16 5 5 16 6 5 16 7 5 16 8 5 16 9 5 17 0 5 17 1 5 17 2 5 17 3 4 17 4 4 17 5 4 17 6 4 17 7 4 17 8 4 17 9 4 18 0 4 18 1 4 18 2 4 18 3 4 14 6 14 7 8 8 18 4 18 5 4 4 Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 30 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE D MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE D HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 4 18 7 4 18 8 4 18 9 4 19 0 4 19 1 4 19 2 4 19 3 4 19 4 4 19 5 4 19 6 3 19 7 3 19 8 3 19 9 3 20 0 3 20 1 3 20 2 3 20 3 3 20 4 3 20 5 3 20 6 3 20 7 3 20 8 3 20 9 3 21 0 3 21 1 3 21 2 3 21 3 3 21 4 3 21 5 3 21 6 3 21 7 3 21 8 3 21 9 3 22 0 3 22 1 3 22 2 3 22 3 3 22 4 3 22 5 3 22 6 3 22 7 2 22 8 2 22 9 2 23 0 2 23 1 2 23 2 2 23 3 2 23 4 2 23 5 2 23 6 2 23 7 2 23 8 2 23 9 2 24 0 2 24 1 1 24 2 1 24 3 1 24 4 1 24 5 1 24 6 1 24 7 1 24 8 1 24 9 1 25 0 1 25 1 1 25 2 1 25 3 1 25 4 0 25 5 0 25 6 0 25 7 0 25 8 0 25 9 0 POND -2 Version 5 17 S/N Executed 11 -18 -1996 11 31 53 >»>»» Summary of Hydrograph Volume «««« Hydrograph 3 \document \96149 \tr55 \PRE D HYD Volume = 257,040 cu ft 5 90 ac -ft 1 Quick TR -55 Version 5 46 S/N Page 1 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 25 14 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE E MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE E HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 10 used in area calculations) >›» Input Parameters Used to Compute Hydrograph « « Subarea AREA CN Tc * Tt Precip I Runoff Ia /p Description (acres) (hrs) (hrs) (in) I (in) input /used Basin "E" 255 00 70 0 0 50 0 00 2 40 I 0 41 136 36 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 255 00 acres or 0 3984 sq mi Peak discharge = 61 cfs > »> Computer Modifications of Input Parameters C«« Input Values Rounded Values Ia /p Subarea Tc * Tt Tc * Tt Interpolated Ia /p Description (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "E" 0 51 0 00 0 50 0 00 Yes * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 25 14 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE E MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE E HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 10 used in area calculations) >»› Summary of Subarea Times to Peak ‹GC‹ Subarea Basin "E" Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 61 12 5 61 12 5 Quick TR -55 Version 5 46 S/N Return Frequency TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Page 3 50 years Executed 11 -18 -1996 11 25 14 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE E MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE E HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Basin "E" 0 0 0 0 1 6 19 40 58 Total (cfs) 0 0 0 0 1 6 19 40 58 Subarea 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 Description hr hr hr hr hr hr hr hr hr Basin "E" 61 55 44 36 25 19 16 14 12 Total (cfs) 61 55 44 36 25 19 16 14 12 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Basin "E" 11 10 9 8 7 7 6 6 5 Total (cfs) 11 10 9 8 7 7 6 6 5 Subarea 18 0 19 0 20 0 22 0 26 0 Description hr hr hr hr hr Basin "E" 5 5 4 4 0 Total (cfs) 5 5 4 4 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 25 14 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE E MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE E HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 1 12 1 6 12 2 19 12 3 40 12 4 58 12 5 61 12 6 55 12 7 44 12 8 36 12 9 30 13 0 25 13 1 22 13 2 19 13 3 18 13 4 16 13 5 15 13 6 14 13 7 13 13 8 12 13 9 12 14 0 11 14 1 11 14 2 10 14 3 10 14 4 10 14 5 9 14 8 8 14 9 8 15 0 8 15 1 8 15 2 8 15 3 7 15 4 7 15 5 7 15 6 7 15 7 7 15 8 7 15 9 7 16 0 7 16 1 7 16 2 7 16 3 6 16 4 6 16 5 6 16 6 6 16 7 6 16 8 6 16 9 6 17 0 6 17 1 6 17 2 6 17 3 5 17 4 5 17 5 5 17 6 5 17 7 5 17 8 5 17 9 5 18 0 5 18 1 5 18 2 5 18 3 5 14 6 9 18 4 14 7 9 18 5 5 5 Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 25 14 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE E MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE E HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 5 18 7 5 18 8 5 18 9 5 19 0 5 19 1 5 19 2 5 19 3 5 19 4 5 19 5 4 19 6 4 19 7 4 19 8 4 19 9 4 20 0 4 20 1 4 20 2 4 20 3 4 20 4 4 20 5 4 20 6 4 20 7 4 20 8 4 20 9 4 21 0 4 21 1 4 21 2 4 21 3 4 21 4 4 21 5 4 21 6 4 21 7 4 21 8 4 21 9 4 22 0 4 22 1 4 22 2 4 22 3 4 22 4 4 22 5 4 22 6 3 22 7 3 22 8 3 22 9 3 23 0 3 23 1 3 23 2 3 23 3 3 23 4 3 23 5 2 23 6 2 23 7 2 23 8 2 23 9 2 24 0 2 24 1 2 24 2 2 24 3 2 24 4 2 24 5 2 24 6 1 24 7 1 24 8 1 24 9 1 25 0 1 25 1 1 25 2 1 25 3 1 25 4 1 25 5 0 25 6 0 25 7 0 25 8 0 25 9 0 POND -2 Version 5 17 S/N Executed 11 -18 -1996 11 26 58 >>>>›).» Summary of Hydrograph Volume ‹<‹‹<‹‹< Hydrograph 3 \document \96149 \tr55 \PRE E HYD Volume = 380,520 cu ft 8 74 ac -ft Quick TR -55 Version 5 46 S/N Page 1 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 55 51 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE F MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE F HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 10 used in area calculations) ››» Input Parameters Used to Compute Hydrograph cccc Subarea AREA CN Tc * Tt Precip Runoff Ia /p Description (acres) (hrs) (hrs) (in) I (in) input /used Basin "F" 340 00 66 0 0 50 0 00 2 40 I 0 29 I 43 43 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 340 00 acres or 0 5313 sq mi Peak discharge = 45 cfs >›» Computer Modifications of Input Parameters ccccc Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "F" 0 49 0 00 0 50 0 00 Yes * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 55 51 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE F MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE F HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 10 used in area calculations) » »» Summary of Subarea Times to Subarea Basin "F" Composite Watershed Peak Discharge at Composite Outfall (cfs) 45 45 Peak «.« Time to Peak at Composite Outfall (hrs) 12 5 12 5 Quick TR -55 Version 5 46 S/N Page 3 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 55 51 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE F MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE F HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Basin "F" 0 0 0 0 0 3 11 26 40 Total (cfs) 0 0 0 0 0 3 11 26 40 Subarea 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 Description hr hr hr hr hr hr hr hr hr Basin "F" 45 43 36 31 23 18 16 14 12 Total (cfs) 45 43 36 31 23 18 16 14 12 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Basin "F" 11 10 9 8 8 7 6 6 6 Total (cfs) 11 10 9 8 8 7 6 6 6 Subarea Description 18 0 19 0 20 0 22 0 26 0 hr hr hr hr hr Basin "F" 6 5 4 4 0 Total (cfs) 6 5 4 4 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 55 51 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE F MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE F HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 0 12 1 3 12 2 11 12 3 26 12 4 40 12 5 45 12 6 43 12 7 36 12 8 31 12 9 27 13 0 23 13 1 20 13 2 18 13 3 17 13 4 16 13 5 15 13 6 14 13 7 13 13 8 12 13 9 12 14 0 11 14 1 11 14 2 10 14 3 10 14 4 10 14 5 9 14 8 8 14 9 8 15 0 8 15 1 8 15 2 8 15 3 8 15 4 8 15 5 8 15 6 8 15 7 8 15 8 7 15 9 7 16 0 7 16 1 7 16 2 7 16 3 6 16 4 6 16 5 6 16 6 6 16 7 6 16 8 6 16 9 6 17 0 6 17 1 6 17 2 6 17 3 6 17 4 6 17 5 6 17 6 6 17 7 6 17 8 6 17 9 6 18 0 6 18 1 6 18 2 6 18 3 6 14 6 9 18 4 14 7 9 18 5 6 6 Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 55 51 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE F MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE F HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 5 22 4 4 18 7 5 22 5 4 18 8 5 22 6 3 18 9 5 22 7 3 19 0 5 22 8 3 19 1 5 22 9 3 19 2 5 23 0 3 19 3 5 23 1 3 19 4 5 23 2 3 19 5 4 23 3 3 19 6 4 23 4 3 19 7 4 23 5 2 19 8 4 23 6 2 19 9 4 23 7 2 20 0 4 23 8 2 20 1 4 23 9 2 20 2 4 24 0 2 20 3 4 24 1 2 20 4 4 24 2 2 20 5 4 24 3 2 20 6 4 24 4 2 20 7 4 24 5 2 20 8 4 24 6 1 20 9 4 24 7 1 21 0 4 24 8 1 21 1 4 24 9 1 21 2 4 25 0 1 21 3 4 25 1 1 21 4 4 25 2 1 21 5 4 25 3 1 21 6 4 25 4 1 21 7 4 25 5 0 21 8 4 25 6 0 21 9 4 25 7 0 22 0 4 25 8 0 22 1 4 25 9 0 22 2 4 22 3 4 POND -2 Version 5 17 S/N Executed 11 -18 -1996 11 56 45 >>>>>>» Summary of Hydrograph Volume «««« Hydrograph 3 \document \96149 \tr55 \PRE F HYD Volume = 353,160 cu ft 8 11 ac-ft Quick TR -55 Ver 5 46 S/N Executed 12 44 51 11 -18 -1996 j \document \96149 \tr55 \PRE G TCT Mirabeau Point Storm Drainage Report Basin "G" (Factor of 10 used in area calculations) Tc COMPUTATIONS FOR Subarea #1 SHEET FLOW (Applicable to To only) Segment ID 1 Surface description grass Manning's roughness coeff , n 0 1500 Flow length, L (total < or = 300) ft 200 0 Two -yr 24 -hr rainfall, P2 in 1 300 Land slope, s ft /ft 0 0100 0 8 007 * (n *L) T= 0 5 P2 * s 0 4 hrs 0 59 = 0 59 SHALLOW CONCENTRATED FLOW Segment ID 1 Surface (paved or unpaved) ? Unpaved Flow length, L ft 100 0 Watercourse slope, s ft /ft 0 0300 0 5 Avg V = Csf * (s) where Unpaved Csf = 16 1345 Paved Csf = 20 3282 T = L / (3600 *V) ft /s 2 7946 hrs 0 01 = 0 01 CHANNEL FLOW Segment ID Cross Sectional Flow Area, a sq ft 0 00 Wetted perimeter, Pw ft 0 00 Hydraulic radius, r = a /Pw ft 0 000 Channel slope, s ft /ft 0 0000 Manning's roughness coeff , n 0 0000 v= 2/3 1/2 1 49 * r * s n Flow length, L T = L / (3600 *V) ft /s 0 0000 ft 0 hrs 0 00 = 0 00 TOTAL TIME (hrs) 0 60 Quick TR -55 Version 5 46 S/N Return Frequency TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Page 1 50 years Executed 11 -18 -1996 12 50 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE H MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE H HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of 10 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip I Runoff Ia /p Description (acres) (hrs) (hrs) (in) I (in) input /used Grass area 356 00 61 0 0 50 0 00 2 40 I 0 17 I 53 50 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 356 00 acres or 0 5562 sq mi Peak discharge = 22 cfs >>» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Grass area 0 56 0 00 0 50 0 00 No Computed Ia /p > 5 * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 12 50 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE H MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE H HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of 10 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Grass area Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 22 12 6 22 12 6 Quick TR -55 Version 5 46 S/N Page 3 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 12 50 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE H MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE H HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Grass area 0 0 0 0 0 0 2 8 16 Total (cfs) 0 0 0 0 0 0 2 8 16 Subarea 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 Description hr hr hr hr hr hr hr hr hr Grass area 21 22 19 17 14 11 10 9 8 Total (cfs) 21 22 19 17 14 11 10 9 8 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Grass area 7 7 6 6 5 5 4 4 4 Total (cfs) 7 7 6 6 5 5 4 4 4 Subarea 18 0 19 0 20 0 22 0 26 0 Description hr hr hr hr hr Grass area 4 3 3 3 0 Total (cfs) 4 3 3 3 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 12 50 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE H MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE H HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 0 12 1 0 12 2 2 12 3 8 12 4 16 12 5 21 12 6 22 12 7 19 12 8 17 12 9 16 13 0 14 13 1 12 13 2 11 13 3 10 13 4 10 13 5 10 13 6 9 13 7 8 13 8 8 13 9 8 14 0 7 14 1 7 14 2 7 14 3 7 14 4 7 14 5 6 14 8 6 14 9 6 15 0 6 15 1 6 15 2 6 15 3 5 15 4 5 15 5 5 15 6 5 15 7 5 15 8 5 15 9 5 16 0 5 16 1 5 16 2 5 16 3 4 16 4 4 16 5 4 16 6 4 16 7 4 16 8 4 16 9 4 17 0 4 17 1 4 17 2 4 17 3 4 17 4 4 17 5 4 17 6 4 17 7 4 17 8 4 17 9 4 18 0 4 18 1 4 18 2 4 18 3 4 14 6 14 7 6 6 18 4 18 5 4 4 Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 12 50 39 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE H MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE H HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 3 18 7 3 18 8 3 18 9 3 19 0 3 19 1 3 19 2 3 19 3 3 19 4 3 19 5 3 19 6 3 19 7 3 19 8 3 19 9 3 20 0 3 20 1 3 20 2 3 20 3 3 20 4 3 20 5 3 20 6 3 20 7 3 20 8 3 20 9 3 21 0 3 21 1 3 21 2 3 21 3 3 21 4 3 21 5 3 21 6 3 21 7 3 21 8 3 21 9 3 22 0 3 22 1 3 22 2 3 22 3 3 22 4 3 22 5 3 22 6 3 22 7 2 22 8 2 22 9 2 23 0 2 23 1 2 23 2 2 23 3 2 23 4 2 23 5 2 23 6 2 23 7 2 23 8 2 23 9 2 24 0 2 24 1 1 24 2 1 24 3 1 24 4 1 24 5 1 24 6 1 24 7 1 24 8 1 24 9 1 25 0 1 25 1 1 25 2 1 25 3 1 25 4 0 25 5 0 25 6 0 25 7 0 25 8 0 25 9 0 POND -2 Version 5 17 S/N Executed 11 -18 -1996 12 51 43 >>>>»» Summary of Hydrograph Volume «««<‹ Hydrograph j \document \96149 \tr55 \PRE H HYD Volume = 219,600 cu ft 5 04 ac -ft Quick TR -55 Version 5 46 S/N Page 1 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 40 42 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE I MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE I HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of 10 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip I Runoff Ia /p Description (acres) (hrs) (hrs) (in) I (in) input /used Grass area 806 00 61 0 0 75 0 00 2 40 I 0 17 I 53 50 * Travel time from subarea outfall to composite watershed outfall point I -- Subarea where user specified interpolation between Ia /p tables Total area = 806 00 acres or 1 2594 sq mi Peak discharge = 40 cfs >>» Computer Modifications of Input Parameters ««< Input Values Rounded Values Ia /p Subarea Tc * Tt Tc * Tt Interpolated Ia /p Description (hr) (hr) (hr) (hr) (Yes /No) Messages Grass area 0 67 0 00 0 75 0 00 No Computed Ia /p > 5 * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version 5 46 S/N Page 2 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 40 42 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE I MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE I HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of 10 used in area calculations) >>» Summary of Subarea Times to Subarea Grass area Composite Watershed Peak Discharge at Composite Outfall (cfs) 40 40 Peak «c< Time to Peak at Composite Outfall (hrs) 12 8 12 8 0 0 0 Pas Quick TR -55 Version 5 46 S/N Page 3 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 40 42 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE I MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE I HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of 10 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11 0 11 3 11 6 11 9 12 0 12 1 12 2 12 3 12 4 Description hr hr hr hr hr hr hr hr hr Grass area 0 0 0 0 0 0 0 3 10 Total (cfs) 0 0 0 0 0 0 0 3 10 Subarea 12 5 12 6 12 7 12 8 13 0 13 2 13 4 13 6 13 8 Description hr hr hr hr hr hr hr hr hr Grass area 20 29 36 40 36 31 27 24 21 Total (cfs) 20 29 36 40 36 31 27 24 21 Subarea 14 0 14 3 14 6 15 0 15 5 16 0 16 5 17 0 17 5 Description hr hr hr hr hr hr hr hr hr Grass area 19 17 15 13 12 11 10 9 9 Total (cfs) 19 17 15 13 12 11 10 9 9 Subarea 18 0 19 0 20 0 22 0 26 0 Description hr hr hr hr hr Grass area 9 8 7 6 0 Total (cfs) 9 8 7 6 0 Quick TR -55 Version 5 46 S/N Page 4 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 40 42 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE I MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE I HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11 0 0 11 1 0 11 2 0 11 3 0 11 4 0 11 5 0 11 6 0 11 7 0 11 8 0 11 9 0 12 0 0 12 1 0 12 2 0 12 3 3 12 4 10 12 5 20 12 6 29 12 7 36 12 8 40 12 9 38 13 0 36 13 1 34 13 2 31 13 3 29 13 4 27 13 5 26 13 6 24 13 7 22 13 8 21 13 9 20 14 0 19 14 1 18 14 2 18 14 3 17 14 4 16 14 5 16 14 8 14 14 9 14 15 0 13 15 1 13 15 2 13 15 3 12 15 4 12 15 5 12 15 6 12 15 7 12 15 8 11 15 9 11 16 0 11 16 1 11 16 2 11 16 3 10 16 4 10 16 5 10 16 6 10 16 7 10 16 8 9 16 9 9 17 0 9 17 1 9 17 2 9 17 3 9 17 4 9 17 5 9 17 6 9 17 7 9 17 8 9 17 9 9 18 0 9 18 1 9 18 2 9 18 3 9 14 6 14 7 15 14 18 4 18 5 9 8 Quick TR -55 Version 5 46 S/N Page 5 Return Frequency 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II Distribution (24 hr Duration Storm) Executed 11 -18 -1996 11 40 42 Watershed file - -> J \DOCUMENT \96149 \TR55 \PRE I MOP Hydrograph file - -> J \DOCUMENT \96149 \TR55 \PRE I HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of 10 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18 6 8 18 7 8 18 8 8 18 9 8 19 0 8 19 1 8 19 2 8 19 3 8 19 4 8 19 5 8 19 6 7 19 7 7 19 8 7 19 9 7 20 0 7 20 1 7 20 2 7 20 3 7 20 4 7 20 5 7 20 6 7 20 7 7 20 8 7 20 9 7 21 0 6 21 1 6 21 2 6 21 3 6 21 4 6 21 5 6 21 6 6 21 7 6 21 8 6 21 9 6 22 0 6 22 1 6 22 2 6 22 3 6 22 4 5 22 5 5 22 6 5 22 7 5 22 8 5 22 9 5 23 0 4 23 1 4 23 2 4 23 3 4 23 4 4 23 5 4 23 6 4 23 7 3 23 8 3 23 9 3 24 0 3 24 1 3 24 2 3 24 3 3 24 4 2 24 5 2 24 6 2 24 7 2 24 8 2 24 9 2 25 0 2 25 1 1 25 2 1 25 3 1 25 4 1 25 5 1 25 6 1 25 7 0 25 8 0 25 9 0 POND -2 Version 5 17 S/N Executed 11 -18 -1996 11 41 51 »>>>›,» Summary of Hydrograph Volume «««<.< Hydrograph 3 \document \96149 \tr55 \PRE I HYD Volume = 479,880 cu ft 11 02 ac -ft xt5'77NGr 50 ? Alt- 5roce-w■ F1-0 VS 13A6,P B AREA. t 3 2. Ae T'" o 62. 1iivs , 31 Z /+rya I = / 4 bi/dr- t = 4 25 Q VOL. alA = 025614x3 2.) // cis / / cf5312y4, = 2,I00 c4- 4E4 = 7, Ace-e.s "r = 0GoS iig6 z 31 OP T - 120 4N /iip G = D 25 Q - era = d z.5 (l Z) 7 = 2 1 cis VOL ` 2. ► C 3") �G7.) - 5; 000 GI 13i. ,iN D 4-4 - / L /Lc s 1: - 0 6o kcs o 3G, ,i r ! 26 wliir. C a25 g crA 025 C! :6616) Vol.. = a (.5(-.;(.40 J = , loo cis 5 Gr5 la lizisru 1i v ?ot4T Pam. PizAlMerg- Coic, CALCULATIONS FOR FUTURE 50 YEAR STORM FLOWS Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:52:41 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT A .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT A.HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 1 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip. Description (acres) (hrs) (hrs) (in) Grass area Runoff Ia /p (in) input /used 35.50 75.0 0.50 0.00 2.40 I 0.59 I.28 .28 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 35.50 acres or 0.05547 sq.mi Peak discharge = 15 cfs >>» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Grass area 0.47 0.00 0.50 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point. Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:52:41 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT A .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT A.HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 1 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Grass area Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 15 12.5 15 12.5 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:52:41 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT A .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT A.HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 1 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 Description hr hr hr hr hr hr hr hr hr Grass area 0 0 0 0 1 2 6 11 14 Total (cfs) 0 0 0 0 1 2 6 11 14 Subarea 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 Description hr hr hr hr hr hr hr hr hr Grass area 15 12 10 8 5 4 3 3 2 Total (cfs) 15 12 10 8 5 4 3 3 2 Subarea 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 Description hr hr hr hr hr hr hr hr hr Grass area 2 2 2 1 1 1 1 1 1 Total (cfs) 2 2 2 1 1 1 1 1 1 Subarea Description 18.0 19.0 20.0 22.0 26.0 hr hr hr hr hr Grass area 1 1 1 1 0 Total (cfs) 1 1 1 1 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:52:41 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT A .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT A.HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 2 11.1 0 14.9 1 11.2 0 15.0 1 11.3 0 15.1 1 11.4 0 15.2 1 11.5 0 15.3 1 11.6 0 15.4 1 11.7 0 15.5 1 11.8 0 15.6 1 11.9 0 15.7 1 12.0 1 15.8 1 12.1 2 15.9 1 12.2 6 16.0 1 12.3 11 16.1 1 12.4 14 16.2 1 12.5 15 16.3 1 12.6 12 16.4 1 12.7 10 16.5 1 12.8 8 16.6 1 12.9 6 16.7 1 13.0 5 16.8 1 13.1 4 16.9 1 13.2 4 17.0 1 13.3 4 17.1 1 13.4 3 17.2 1 13.5 3 17.3 1 13.6 3 17.4 1 13.7 2 17.5 1 13.8 2 17.6 1 13.9 2 17.7 1 14.0 2 17.8 1 14.1 2 17.9 1 14.2 2 18.0 1 14.3 2 18.1 1 14.4 2 18.2 1 14.5 2 18.3 1 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:52:41 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT A .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT A.HYD Mirabeau Point Project Storm Drainage Report Basin "A" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 1 18.7 1 18.8 1 18.9 1 19.0 1 19.1 1 19.2 1 19.3 1 19.4 1 19.5 1 19.6 1 19.7 1 19.8 1 19.9 1 20.0 1 20.1 1 20.2 1 20.3 1 20.4 1 20.5 1 20.6 1 20.7 1 20.8 1 20.9 1 21.0 1 21.1 1 21.2 1 21.3 1 21.4 1 21.5 1 21.6 1 21.7 1 21.8 1 21.9 1 22.0 1 22.1 1 22.2 1 22.3 1 22.4 1 22.5 1 22.6 1 22.7 1 22.8 1 22.9 1 23.0 1 23.1 1 23.2 1 23.3 1 23.4 1 23.5 1 23.6 1 23.7 1 23.8 1 23.9 1 24.0 0 24.1 0 24.2 0 24.3 0 24.4 0 24.5 0 24.6 0 24.7 0 24.8 0 24.9 0 25.0 0 25.1 0 25.2 0 25.3 0 25.4 0 25.5 0 25.6 0 25.7 0 25.8 0 25.9 0 POND -2 Version: 5.17 S /N: Executed 11 -18 -1996 14:05:33 >>>>>>» Summary of Hydrograph Volume «<<«« Hydrograph: j: \document \96149 \tr55 \FUT A .HYD Volume = 81,360 cu.ft. 1.87 ac -ft Quick TR -55 Ver.5.46 S /N: Executed: 16:20:35 11 -18 -1996 j: \document \96149 \tr55 \FUT B.TCT Mirabeau Point Storm Drainage Report Basin "B" (Factor of 1 used in area calculations) Tc COMPUTATIONS FOR: Subarea #1 SHEET FLOW (Applicable to Tc only) Segment ID 1 Surface description pavement Manning's roughness coeff., n 0.0110 Flow length, L (total < or = 300) ft 150.0 Two -yr 24 -hr rainfall, P2 in 1.300 Land slope, s ft /ft 0.0200 0.8 .007 * (n *L) T= 0.5 P2 * s 0.4 hrs 0.04 = 0.04 SHALLOW CONCENTRATED FLOW Segment ID 2 Surface (paved or unpaved) ? Paved Flow length, L ft 450.0 Watercourse slope, s ft /ft 0.0200 0.5 Avg.V = Csf * (s) ft /s 2.8748 where: Unpaved Csf = 16.1345 Paved Csf = 20.3282 T = L / (3600 *V) hrs 0.04 = 0.04 CHANNEL FLOW Segment ID Cross Sectional Flow Area, a sq.ft 0.00 Wetted perimeter, Pw ft 0.00 Hydraulic radius, r = a /Pw ft 0.000 Channel slope, s ft /ft 0.0000 Manning's roughness coeff., n 0.0000 V = 2/3 1/2 1.49 * r * s n Flow length, L T = L / (3600 *V) ft /s 0.0000 ft 0 hrs 0.00 = 0.00 TOTAL TIME (hrs 0.09 1• ►J Quick TR -55 Ver.5.46 S /N: Executed: 16:24:36 11 -18 -1996 j: \document \96149 \tr55 \FUT C.TCT Mirabeau Point Storm Drainage Report Basin "C" (Factor of 1 used in area calculations) Tc COMPUTATIONS FOR: Subarea #1 SHEET FLOW (Applicable to Tc only) Segment ID 1 Surface description pavement Manning's roughness coeff., n 0.0110 Flow length, L (total < or = 300) ft 150.0 Two -yr 24 -hr rainfall, P2 in 1.300 Land slope, s ft /ft 0.0200 0.8 .007 * (n *L) T = hrs 0.04 = 0.04 0.5 P2 * s 0.4 SHALLOW CONCENTRATED FLOW Segment ID 2 Surface (paved or unpaved)? Paved Flow length, L ft 1050.0 Watercourse slope, s ft /ft 0.0200 0.5 Avg.V = Csf * (s) where: Unpaved Csf = 16.1345 Paved Csf = 20.3282 ft /s 2.8748 T = L / (3600 *V) hrs 0.10 = 0.10 CHANNEL FLOW Segment ID Cross Sectional Flow Area, a sq.ft 0.00 Wetted perimeter, Pw ft 0.00 Hydraulic radius, r = a /Pw ft 0.000 Channel slope, s ft /ft 0.0000 Manning's roughness coeff., n 0.0000 V= 2/3 1/2 1.49 * r * s n Flow length, L T = L / (3600 *V) ft /s 0.0000 ft 0 hrs 0.00 = 0.00 TOTAL TIME (hrs) Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:41:57 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT D .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT D5.HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 1 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip. Description (acres) (hrs) (hrs) (in) Runoff Ia /p (in) input /used Basin "D" 27.90 77.0 0.75 0.00 2.40 1 0.68 I.25 .25 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 27.90 acres or 0.04359 sq.mi Peak discharge = 11 cfs >>» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "D" 0.63 0.00 0.75 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point. Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:41:57 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT D .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT D5.HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 1 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Basin "D" Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 11 12.7 11 12.7 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:41:57 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT D .MOP Hydrograph file: - -> J:\DOCUMENT\96149\TR55\FUT D5.HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 1 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 Description hr hr hr hr hr hr hr hr hr Basin "D" 0 0 0 0 0 1 2 3 6 Total (cfs) 0 0 0 0 0 1 2 3 6 Subarea 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 Description hr hr hr hr hr hr hr hr hr Basin "D" 9 10 11 10 7 5 4 3 3 Total (cfs) 9 10 11 10 7 5 4 3 3 Subarea 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 Description hr hr hr hr hr hr hr hr hr Basin "D" 2 2 2 1 1 1 1 1 1 Total (cfs) 2 2 2 1 1 1 1 1 1 Subarea 18.0 19.0 20.0 22.0 26.0 Description hr hr hr hr hr Basin "D" 1 1 1 1 0 Total (cfs) 1 1 1 1 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:41:57 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT D .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT D5.HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 2 11.1 0 14.9 1 11.2 0 15.0 1 11.3 0 15.1 1 11.4 0 15.2 1 11.5 0 15.3 1 11.6 0 15.4 1 11.7 0 15.5 1 11.8 0 15.6 1 11.9 0 15.7 1 12.0 0 15.8 1 12.1 1 15.9 1 12.2 2 16.0 1 12.3 3 16.1 1 12.4 6 16.2 1 12.5 9 16.3 1 12.6 10 16.4 1 12.7 11 16.5 1 12.8 10 16.6 1 12.9 8 16.7 1 13.0 7 16.8 1 13.1 6 16.9 1 13.2 5 17.0 1 13.3 4 17.1 1 13.4 4 17.2 1 13.5 4 17.3 1 13.6 3 17.4 1 13.7 3 17.5 1 13.8 3 17.6 1 13.9 2 17.7 1 14.0 2 17.8 1 14.1 2 17.9 1 14.2 2 18.0 1 14.3 2 18.1 1 14.4 2 18.2 1 14.5 2 18.3 1 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:41:57 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT D .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT D5.HYD Mirabeau Point Project Storm Drainage Report Basin "D" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 1 18.7 1 18.8 1 18.9 1 19.0 1 19.1 1 19.2 1 19.3 1 19.4 1 19.5 1 19.6 1 19.7 1 19.8 1 19.9 1 20.0 1 20.1 1 20.2 1 20.3 1 20.4 1 20.5 1 20.6 1 20.7 1 20.8 1 20.9 1 21.0 1 21.1 1 21.2 1 21.3 1 21.4 1 21.5 1 21.6 1 21.7 1 21.8 1 21.9 1 22.0 1 22.1 1 22.2 1 22.3 1 22.4 1 22.5 1 22.6 1 22.7 1 22.8 1 22.9 1 23.0 1 23.1 1 23.2 1 23.3 1 23.4 1 23.5 1 23.6 1 23.7 1 23.8 1 23.9 1 24.0 0 24.1 0 24.2 0 24.3 0 24.4 0 24.5 0 24.6 0 24.7 0 24.8 0 24.9 0 25.0 0 25.1 0 25.2 0 25.3 0 25.4 0 25.5 0 25.6 0 25.7 0 25.8 0 25.9 0 POND -2 Version: 5.17 S /N: Executed 11 -27 -1996 15:00:04 >>>>>>» Summary of Hydrograph Volume «««« Hydrograph: j: \document \96149 \tr55 \FUT D5 .HYD Volume = 75,600 cu.ft. 1.74 ac -ft Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:50:02 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT E .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT E5.HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 1 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea Description AREA CN Tc * Tt Precip. (acres) (hrs) (hrs) (in) Runoff Ia /p (in) input /used Basin "E" 25.50 77.0 0.50 0.00 2.40 1 0.68 I.25 .25 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 25.50 acres or 0.03984 sq.mi Peak discharge = 12 cfs >>» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "E" 0.51 0.00 0.50 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point. Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:50:02 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT E .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT E5.HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 1 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Basin "E" Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 12 12.4 12 12.4 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:50:02 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT E .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT E5.HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 1 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 Description hr hr hr hr hr hr hr hr hr Basin "E" 0 0 0 0 1 2 5 10 12 Total (cfs) 0 0 0 0 1 2 5 10 12 Subarea 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 Description hr hr hr hr hr hr hr hr hr Basin "E" 12 10 8 6 4 3 2 2 2 Total (cfs) 12 10 8 6 4 3 2 2 2 Subarea 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 Description hr hr hr hr hr hr hr hr hr Basin "E" 2 1 1 1 1 1 1 1 1 Total (cfs) 2 1 1 1 1 1 1 1 1 Subarea 18.0 19.0 20.0 22.0 26.0 Description hr hr hr hr hr Basin "E" 1 1 1 0 0 Total (cfs) 1 1 1 0 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Stormy Executed: 11 -27 -1996 14 :50:02 Watershed file: --> J :`DOCUMENT \96149 \TR55\FUT E .MOP Hydrograph file: --a J : \DOCUMENT\ 9 614 9 \TR5 5 \FUT E5 . HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 1 11.1 0 14.9 1 11.2 0 15.0 1 11.3 0 15.1 1 11.4 0 15.2 1 11.5 0 15.3 1 11.6 0 15.4 1 11.7 0 15.5 1 11.8 0 15.6 1 11.9 0 15.7 1 12.0 1 15.8 1 12.1 2 15.9 1 12.2 5 16.0 1 12.3 10 16.1 1 12.4 12 16.2 1 12.5 12 16.3 1 12.6 10 16.4 1 12.7 8 16.5 1 12.8 6 16.6 1 12.9 5 16.7 1 13.0 4 16.8 1 13.1 4 16.9 1 13.2 3 17.0 1 13.3 ' 2 17.1 � 1 13.4 2 1(.2 1 13.5 2 17.3 1 13.6 2 17.4 1 13.7 2 17.5 1 13.8 2 17.6 1 13.9 2 17.7 1 14.0 2 17.8 1 14.1 2 17.9 1 14.2 1 18.0 1 14.3 1 18.1 1 14.4 1 18.2 1 14.5 1 18.3 1 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -27 -1996 14:50:02 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT E .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT E5.HYD Mirabeau Point Project Storm Drainage Report Basin "E" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 1 18.7 1 18.8 1 18.9 1 19.0 1 19.1 1 19.2 1 19.3 1 19.4 1 19.5 1 19.6 1 19.7 1 19.8 1 19.9 1 20.0 1 20.1 1 20.2 1 20.3 1 20.4 1 20.5 1 20.6 1 20.7 1 20.8 1 20.9 1 21.0 0 21.1 0 21.2 0 21.3 0 21.4 0 21.5 0 21.6 0 21.7 0 21.8 0 21.9 0 22.0 0 22.1 0 22.2 0 22.3 0 22.4 0 22.5 0 22.6 0 22.7 0 22.8 0 22.9 0 23.0 0 23.1 0 23.2 0 23.3 0 23.4 0 23.5 0 23.6 0 23.7 0 23.8 0 23.9 0 24.0 0 24.1 0 24.2 0 24.3 0 24.4 0 24.5 0 24.6 0 24.7 0 24.8 0 24.9 0 25.0 0 25.1 0 25.2 0 25.3 0 25.4 0 25.5 0 25.6 0 25.7 0 25.8 0 25.9 0 POND -2 Version: 5.17 S /N: Executed 11 -27 -1996 15:00:56 >>>>»» Summary of Hydrograph Volume «««« Hydrograph: j: \document \96149 \tr55 \FUT E5 .HYD Volume = 60,480 cu.ft. 1.39 ac -ft Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:47:51 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT F .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT F.HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 1 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip. Description (acres) (hrs) (hrs) (in) Runoff Ia /p (in) input /used Basin "F" 34.00 75.0 0.50 0.00 2.40 1 0.59 I.28 .28 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 34.00 acres or 0.05313 sq.mi Peak discharge = 14 cfs >>» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Basin "F" 0.49 0.00 0.50 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point. Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:47:51 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT F .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT F.HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 1 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Basin "F" Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 14 12.4 14 12.4 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR- 5 5 TABULAR HYDROGRAPH METHOD Type i1. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:47:51 Watershed file: --> J:\DOCUMENT\96149\TR55\FUT F .MOP Hydrograph file: - -> J :\DOCUMENT\96149\TR55\FUT F.HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 1 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 Description hr hr hr hr hr hr hr hr hr Basin "F" 0 0 0 0 1 2 5 10 14 Total (cfs) 0 0 0 0 1 2 5 10 14 Subarea 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 Description hr hr hr hr hr hr hr hr hr Basin "F " 14 12 9 7 5 4 3 2 2 Total (cfs) 14 12 9 7 5 4 3 2 2 Subarea 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 Description hr hr hr hr hr hr hr hr hr Basin "F " 2 2 2 1 1 1 1 1 1 Total (cfs) 2 2 2 1 1 1 1 1 1 Subarea 18.0 19.0 20.0 22.0 26.0 Description hr hr hr hr hr Basin "F" 1 1 1 1 0 Total (cfs) 1 1 1 1 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:47 :51 Watershed file: - -> J:\DOCUMENT\96149\TR55\FUT F .MOP Hydrograph file: - -> J:\DOCUMENT\96149\TR55\FUT F.HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 2 11.1 0 14.9 1 11.2 0 15.0 1 11.3 0 15.1 1 11.4 0 15.2 1 11.5 0 15.3 1 11.6 0 15.4 1 11.7 0 15.5 1 11.8 0 15.6 1 11.9 0 15.7 1 12.0 1 15.8 1 12.1 2 15.9 1 12.2 5 16.0 1 12.3 10 16.1 1 12.4 14 16.2 1 12.5 14 16.3 1 12.6 12 16.4 1 12.7 9 16.5 1 12.8 7 16.6 1 12.9 6 16.7 1 13.0 5 16.8 1 13.1 4 16.9 1 13.2 4 17.0 1 13.3 4 17.1 1 13.4 3 17.2 1 13.5 3 17.3 1 13.6 2 17.4 1 13.7 2 17.5 1 13.8 2 17.6 1 13.9 2 17.7 1 14.0 2 17.8 1 14.1 2 17.9 1 14.2 2 18.0 1 14.3 2 18.1 1 14.4 2 18.2 1 14.5 2 18.3 1 14.6 14.7 2 2 18.4 18.5 1 1 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:47:51 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT F .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT F.HYD Mirabeau Point Project Storm Drainage Report Basin "F" (Factor of 1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 1 22.4 1 18.7 1 22.5 1 18.8 1 22.6 1 18.9 1 22.7 1 19.0 1 22.8 1 19.1 1 22.9 1 19.2 1 23.0 1 19.3 1 23.1 1 19.4 1 23.2 1 19.5 1 23.3 1 19.6 1 23.4 1 19.7 1 23.5 1 19.8 1 23.6 1 19.9 1 23.7 1 20.0 1 23.8 1 20.1 1 23.9 1 20.2 1 24.0 0 20.3 1 24.1 0 20.4 1 24.2 0 20.5 1 24.3 0 20.6 1 24.4 0 20.7 1 24.5 0 20.8 1 24.6 0 20.9 1 24.7 0 21.0 1 24.8 0 21.1 1 24.9 0 21.2 1 25.0 0 21.3 1 25.1 0 21.4 1 25.2 0 21.5 1 25.3 0 21.6 1 25.4 0 21.7 1 25.5 0 21.8 1 25.6 0 21.9 1 25.7 0 22.0 1 25.8 0 22.1 1 25.9 0 22.2 1 22.3 1 POND -2 Version: 5.17 S /N: Executed 11 -18 -1996 14:51:09 >>>>»» Summary of Hydrograph Volume «««« Hydrograph: j: \document \96149 \tr55 \FUT F .HYD Volume = 79,200 cu.ft. 1.82 ac -ft 11 11 1 1 1 1 Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:44:34 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of .5 used in area calculations) H .MOP H.HYD >>» Input Parameters Used to Compute Hydrograph «« Subarea Description AREA CN (acres) Tc * Tt Precip. (hrs) (hrs) (in) Runoff Ia /p (in) input /used Grass area 17.80 83.0 0.50 0.00 2.40 1 0.98 I.17 .17 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 17.80 acres or 0.02781 sq.mi Peak discharge = 14 cfs >>» Computer Modifications of Input Parameters ‹«« Subarea Description Input Values Tc * Tt (hr) (hr) Rounded Values Ia /p Tc * Tt Interpolated (hr) (hr) (Yes /No) Ia /p Messages Grass area 0.57 0.00 0.50 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:44:34 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT H .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT H.HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of .5 used in area calculations) »» Summary of Subarea Times to Peak «« Subarea Grass area Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 14 12.4 14 12.4 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR- 5 5 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:44:34 Watershed file: - -> J: \DOCUMENT \96149 \TR55\FUT H .MOP Hydrograph file: - -> J: \DOCUMENT\96149 \TR55\FUT H.HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of .5 used in area calculations) Composite Hydrograph Summary (cfs) Subarea Description II Grass area Total (cfs) 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 hr hr hr hr hr hr hr hr hr 0 0 1 1 2 4 7 11 14 0 0 1 1 2 4 7 11 14 Subarea Description Grass area 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 hr hr hr hr hr hr hr hr hr 13 11 8 6 4 3 2 2 2 Total (cfs) 13 11 8 6 4 3 2 2 2 Subarea Description Grass area 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 hr hr hr hr hr hr hr hr hr 1 1 1 1 1 1 1 1 1 Total (cfs) 1 1 1 1 1 1 1 1 Subarea 18.0 19.0 20.0 22.0 26.0 Description hr hr hr hr hr Grass area 1 1 0 0 0 Total (cfs) 1 1 0 0 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:44:34 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT H .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT H.HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of .5 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 1 11.1 0 14.9 1 11.2 0 15.0 1 11.3 0 15.1 1 11.4 0 15.2 1 11.5 1 15.3 1 11.6 1 15.4 1 11.7 1 15.5 1 11.8 1 15.6 1 11.9 1 15.7 1 12.0 2 15.8 1 12.1 4 15.9 1 12.2 7 16.0 1 12.3 11 16.1 1 12.4 14 16.2 1 12.5 13 16.3 1 12.6 11 16.4 1 12.7 8 16.5 1 12.8 6 16.6 1 12.9 5 16.7 1 13.0 4 16.8 1 13.1 4 16.9 1 13.2 3 17.0 1 13.3 2 17.1 1 13.4 2 17.2 1 13.5 2 17.3 1 13.6 2 17.4 1 13.7 2 17.5 1 13.8 2 17.6 1 13.9 2 17.7 1 14.0 1 17.8 1 14.1 1 17.9 1 14.2 1 18.0 1 14.3 1 18.1 1 14.4 1 18.2 1 14.5 1 18.3 1 14.6 1 14.7 1 18.4 18.5 1 1 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:44:34 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT H .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT H.HYD Mirabeau Point Project Storm Drainage Report Basin "H" (Factor of .5 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 1 22.4 0 18.7 1 22.5 0 18.8 1 22.6 0 18.9 1 22.7 0 19.0 1 22.8 0 19.1 1 22.9 0 19.2 1 23.0 0 19.3 1 23.1 0 19.4 1 23.2 0 19.5 0 23.3 0 19.6 0 23.4 0 19.7 0 23.5 0 19.8 0 23.6 0 19.9 0 23.7 0 20.0 0 23.8 0 20.1 0 23.9 0 20.2 0 24.0 0 20.3 0 24.1 0 20.4 0 24.2 0 20.5 0 24.3 0 20.6 0 24.4 0 20.7 0 24.5 0 20.8 0 24.6 0 20.9 0 24.7 0 21.0 0 24.8 0 21.1 0 24.9 0 21.2 0 25.0 0 21.3 0 25.1 0 21.4 0 25.2 0 21.5 0 25.3 0 21.6 0 25.4 0 21.7 0 25.5 0 21.8 0 25.6 0 21.9 0 25.7 0 22.0 0 25.8 0 22.1 0 25.9 0 22.2 0 22.3 0 POND -2 Version: 5.17 S /N: Executed 11 -18 -1996 15:20:14 ›.›).›),›» Summary of Hydrograph Volume ««“<‹ « “<‹ Hydrograph: j: \document \96149\tr55 \FUT H .HYD Volume = 59,760 cu.ft. 1.37 ac -ft Quick TR -55 Version: 5.46 S /N: Page 1 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:42:47 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT I .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT I.HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of .1 used in area calculations) >>» Input Parameters Used to Compute Hydrograph «« Subarea AREA CN Tc * Tt Precip. Description (acres) (hrs) (hrs) (in) Grass area Runoff Ia /p (in) input /used 8.06 84.0 0.50 0.00 2.40 I 1.04 I.16 .16 * Travel time from subarea outfall to composite watershed outfall point. I -- Subarea where user specified interpolation between Ia /p tables. Total area = 8.06 acres or 0.01259 sq.mi Peak discharge = 7 cfs »» Computer Modifications of Input Parameters ««< Subarea Description Input Values Rounded Values Ia /p Tc * Tt Tc * Tt Interpolated Ia /p (hr) (hr) (hr) (hr) (Yes /No) Messages Grass area 0.55 0.00 0.50 0.00 Yes * Travel time from subarea outfall to composite watershed outfall point. Quick TR -55 Version: 5.46 S /N: Page 2 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:42:47 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT I .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT I.HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of .1 used in area calculations) >>» Summary of Subarea Times to Peak «« Subarea Grass area Composite Watershed Peak Discharge at Time to Peak at Composite Outfall Composite Outfall (cfs) (hrs) 7 12.4 7 12.4 Quick TR -55 Version: 5.46 S /N: Page 3 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:42:47 Watershed file: --> J:\DOCUMENT\96149\TR55\FUT I .MOP Hydrograph file: --> J:\DOCUMENT\96149\TR55\FUT I.HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of .1 used in area calculations) Composite Hydrograph Summary (cfs) Subarea 11.0 11.3 11.6 11.9 12.0 12.1 12.2 12.3 12.4 Description hr hr hr hr hr hr hr hr hr Grass area 0 0 0 1 1 2 3 6 7 Total (cfs) 0 0 0 1 1 2 3 6 7 Subarea 12.5 12.6 12.7 12.8 13.0 13.2 13.4 13.6 13.8 Description hr hr hr hr hr hr hr hr hr Grass area 6 5 4 3 2 1 1 1 1 Total (cfs) 6 5 4 3 2 1 1 1 1 Subarea 14.0 14.3 14.6 15.0 15.5 16.0 16.5 17.0 17.5 Description hr hr hr hr hr hr hr hr hr Grass area 1 1 1 0 0 0 0 0 0 Total (cfs) 1 1 1 0 0 0 0 o 0 Subarea 18.0 19.0 20.0 22.0 26.0 Description hr hr hr hr hr Grass area 0 0 0 0 0 Total (cfs) 0 0 0 0 0 Quick TR -55 Version: 5.46 S /N: Page 4 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:42:47 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT I .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT I.HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of .1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 11.0 0 14.8 0 11.1 0 14.9 0 11.2 0 15.0 0 11.3 0 15.1 0 11.4 0 15.2 0 11.5 0 15.3 0 11.6 0 15.4 0 11.7 0 15.5 0 11.8 1 15.6 0 11.9 1 15.7 0 12.0 1 15.8 0 12.1 2 15.9 0 12.2 3 16.0 0 12.3 6 16.1 0 12.4 7 16.2 0 12.5 6 16.3 0 12.6 5 16.4 0 12.7 4 16.5 0 12.8 3 16.6 0 12.9 2 16.7 0 13.0 2 16.8 0 13.1 2 16.9 0 13.2 1 17.0 0 13.3 1 17.1 0 13.4 1 17.2 0 13.5 1 17.3 0 13.6 1 17.4 0 13.7 1 17.5 0 13.8 1 17.6 0 13.9 1 17.7 0 14.0 1 17.8 0 14.1 1 17.9 0 14.2 1 18.0 0 14.3 1 18.1 0 14.4 1 18.2 0 14.5 1 18.3 0 14.6 1 18.4 0 14.7 1 18.5 0 Quick TR -55 Version: 5.46 S /N: Page 5 Return Frequency: 50 years TR -55 TABULAR HYDROGRAPH METHOD Type II. Distribution (24 hr. Duration Storm) Executed: 11 -18 -1996 15:42:47 Watershed file: - -> J: \DOCUMENT \96149 \TR55 \FUT I .MOP Hydrograph file: - -> J: \DOCUMENT \96149 \TR55 \FUT I.HYD Mirabeau Point Project Storm Drainage Report Basin "I" (Factor of .1 used in area calculations) Time Flow Time Flow (hrs) (cfs) (hrs) (cfs) 18.6 0 18.7 0 18.8 0 18.9 0 19.0 0 19.1 0 19.2 0 19.3 0 19.4 0 19.5 0 19.6 0 19.7 0 19.8 0 19.9 0 20.0 0 20.1 0 20.2 0 20.3 0 20.4 0 20.5 0 20.6 0 20.7 0 20.8 0 20.9 0 21.0 0 21.1 0 21.2 0 21.3 0 21.4 0 21.5 0 21.6 0 21.7 0 21.8 0 21.9 0 22.0 0 22.1 0 22.2 0 22.3 0 22.4 0 22.5 0 22.6 0 22.7 0 22.8 0 22.9 0 23.0 0 23.1 0 23.2 0 23.3 0 23.4 0 23.5 0 23.6 0 23.7 0 23.8 0 23.9 0 24.0 0 24.1 0 24.2 0 24.3 0 24.4 0 24.5 0 24.6 0 24.7 0 24.8 0 24.9 0 25.0 0 25.1 0 25.2 0 25.3 0 25.4 0 25.5 0 25.6 0 25.7 0 25.8 0 25.9 0 POND -2 Version: 5.17 S /N: Executed 11 -18 -1996 15:38:26 >>>>»» Summary of Hydrograph Volume «««<< Hydrograph: j: \document \96149 \tr55 \FUT I .HYD Volume = 21,960 cu.ft. 0.50 ac -ft tA50 •g•. Aseta 50 6A¢ b-r-op.s1A Ft-ow5 3.2 AFt5 Iu�rArDiA IoOrr P141-. P, A►4d4 . ard4' -ref : 0 q PIPS = 5,4 ofios 4. 4- myµz- C O. $o = CIA = D. $o(4.4)(3.1) _ /1.3 s joL. _ //. 3 = 3 Goo Gc l-tfr 7 ► res q ow. T= 3.4 'lJFr.. G ( a D. 00&.47.1) _ 11,5 c -rs VOL- " 11.5 (9)(4o) _ /0 400 f rEA _ /. 6 . / c rg . 5". 0 pow iatvrts) 1 = .4.57 G = d 6.0 Q s C I = ago (4.5 7 (l. G) _ cls $ c-Fs (s- y _ goo c-F CALCULATIONS FOR TYPICAL "208"/STORMWATER BASIN ENGINEERING PEAK FLOW CALCULATION Tot. Area Imp. Area C= CASE 1 50 -year STORM PROJECT Mirabeau Point BASIN: Typical Basin 5.00 Acres 163350 SF (75% of total area) 0.15 (for lawn) 45 ft , Overland Flow Ct = L= n= S= 0.15 45 ft. 0.40 0.020 Tc = 2.75 min., by Equation 3 -2 of Guidelines 200 ft . Gutter flow Z1 = Z2 = n= S= 50.0 3.5 0.016 0.008 d= 0.150 ft. A R Q Tc Tc total 1 Qc 0.60 0.07 0.89 Qpeak for Case 1 = 3.43 cfs CASE 2 2.25 5.00 4.58 3.43 Case 2 assumes a Time of Concentration Tess than 5 minutes so that the peak flow = .90(4.58)(Imp. Area) = 15.46 cfs So, the Peak flow for the Basin is the greater of the two flows, 15.46 cfs BOWSTRING METHOD DETENTION BASIN DESIGN Time Increment (min) 5 Time of Conc. (min) 5.00 Outflow (cfs) 3 Design Year Flow 50 Area (acres) 5 Impervious Area (sq ft) 163350 'C' Factor 0.7125 50 -year Volume Provided Area ' C 3.563 PROJECT: Mirabeau Point BASIN: Typical Basin DESIGNER: TAS DATE: 11/27/96 75% Impervious (c = 0.90) 25% Lawn (c = 0.15) Time Time Inc. Intens. Q Devel. Vol.ln Vol.Out Storage (min) (sec) (in /hr) (cfs) (cu ft) (cu ft) (cu ft) 5.00 300 4.58 16.31 6561 900 5660 5 300 4.58 16.32 6559 900 5659 10 600 3.20 11.40 8003 1800 6203 < == 15 900 2.45 8.73 8746 2700 6046 20 1200 1.95 6.95 9045 3600 5445 25 1500 1.62 5.77 9246 4500 4746 30 1800 1.56 5.56 10571 5400 5171 35 2100 1.28 4.56 10041 6300 3741 40 2400 1.19 4.22 10563 7200 3363 45 2700 1.08 3.85 10781 8100 2681 50 3000 0.99 3.53 10941 9000 1941 55 3300 0.92 3.28 11150 9900 1250 60 3600 0.87 3.10 11474 10800 674 65 3900 0.82 2.92 11691 11700 -9 70 4200 0.80 2.85 12261 12600 -339 75 4500 0.77 2.74 12624 13500 -876 80 4800 0.75 2.67 13098 14400 -1302 85 5100 0.72 2.57 13343 15300 -1957 90 5400 0.71 2.53 13917 16200 -2283 95 5700 0.69 2.46 14262 17100 -2838 100 6000 0.67 2.39 14565 18000 -3435 208' DRAINAGE POND CALCULATIONS Required '208' Storage Volume = Impervious Area x .5 in / 12 in /ft 50 year Volume Provided N/A 6806 cu ft DRYWELL REQUIREMENTS - 50 YEAR DESIGN STO Maximum Storage Required by Bowstring 6203 cu ft Number and Type of Drywelis Required 0 Single 3 Double Sheetl CN =90 CN =93 CN =95 CN =98 Oct 38 51 62 82 Nov 55 66 75 89 Dec 58 68 76 90 Jan 55 66 75 89 Feb 47 59 68 86 Mar 43 55 65 84 Percent Runoff Monthly Precipitation 1.21 inches 2.05 2.21 2.05 1.56 1.37 Percent Runoff Using SCS Hydrograph Method 100 90 80 70 60 SO 40 30 Oct Nov Dec Jan Month Page 1 Feb Mar CN =90 CN =93 —CN = 95 �` ~"CNz98