The URL can be used to link to this page

Browse Search

Home My WebLink About20093766.tiffERIE SUBSTATION EXPANSION Preliminary Drainage Report Prepared for: Tri-State Generation & Transmission Association, Inc. 1100 West 116th Avenue Westminster, Colorado 80233 April 15, 2009 Prepared by: Manhard Consulting, Ltd. 7442 South Tucson Way, Suite 190-A Centennial, Colorado 80112 Contact: Kevin Barney Phone (303) 708-0500 Fax (303) 708-0400 TSGERC (071217) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • CERTIFICATION Engineer's Statement: • I hereby certify that this report for the preliminary drainage design of the "Erie Substation Ex.ansion" was prepared by me (or under my direct supervision) in accordance with the provisio County Storm Drainage Criteria for the owners thereof. Kevin P. Barney, P.E. Registered Professional Engin State of Colorado No. 39719 Erie Substation Expansion: Preliminary Drainage Report • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Table of Contents I. General Location and Description 1 A. Location 1 B. Property Description 1 II. Drainage Basins and Sub Basins 2 A. Major Basin Description 2 B. Sub -Basin Description 2 III. Drainage Design Criteria 2 A. Development Criteria Reference and Constraints 2-3 B. Hydrological Criteria 3 C. Hydraulic Criteria 3-4 IV. Drainage Facility Design 4 A. General Concept 4 B. Specific Details 4-5 V. Conclusions 5 A. Compliance with the Weld County CODE 5 B. Drainage Concept 5 C. References 6 VI. Appendices A. Maps B. Hydrologic Computations C. Hydraulic Computations D. Exhibits Erie Substation Expansion: Preliminary Drainage Report ii • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • I. General Location and Description A. Location The proposed development is located in the Northwest Quarter of Section 25, Township 1 North, Range 68 West of the Sixth Principal Meridian, County of Weld, State of Colorado. The proposed site is bordered to the north by County Road 6 right of way, to the east by Union Pacific Railroad right of way, to the south by an existing concrete/asphalt production facility owned by Sand Land Properties, LLC, and to the west by an existing farm owned by John C. Brookman. This site, along with the surrounding developments listed above, are located within unincorporated Weld County. A Vicinity Map is included in Appendix A of this report that shows the exact location of the subject development and the surrounding developments. The proposed site contains an existing irrigation canal, the East Branch Bull Canal, that flows from west to east along the south side of the property. The site also includes an unnamed ditch in the northwest corner of the property that flows in a northeasterly direction towards Weld County Road 6. B. Description of Property The proposed Erie Substation Expansion will occur on Lot B of the Recorded Exemption No. 1467- 25-2 RE -4852. Lot B is approximately 39 acres in size and is owned by Tri-State Generation & Transmission Association, Inc (Tri-State). However, the Erie Substation Expansion will only disturb approximately 7.60 acres of Lot B. The existing property generally slopes from south to north at an average slope between 1%-2%. The majority of the existing ground cover consists of natural grasses and weeds. The site includes an existing 115KV Substation that is owned by Tri-State, two single -story buildings that will be removed with this project, transmission poles, a gravel roadway, the East Branch Bull Canal, and an unnamed ditch on the northwest corner of the property. Soil types in the area are primarily Ulm clay loam (approximately 93% of the site) according to the USDA Natural Resources Conservation Service soil survey. The remaining portion of the site consists of Weld loam soils. Both of these soil types have a hydraulic rating of type C. See Appendix A of this report for a Soils Map and detailed information regarding the soil types on this site. According to the Geotechnical Investigation prepared by CTL Thompson, groundwater was measured at depths ranging from approximately 12 to 16 feet below existing grades, and is not expected to significantly affect site development. The subject development is an expansion of the existing 115KV Yard Substation that is owned by Tri-State. The project will include construction of a gravel pad that will contain the various switches, transformers, breakers, and other equipment required for the substation, construction of gravel access roads, construction of swales and storm sewer culverts, and construction of a proposed detention and water quality basin with an outlet structure and storm sewer pipe outlet. Erie Substation Expansion: Preliminary Drainage Report 1 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • II. Drainage Basins and Sub -Basins A. Major Basin Description • According to Weld County Public Works staff, there are not any Master Drainage Reports available that cover the subject property. However, a detailed review of the Frederick USGS Quadrangle Map indicates where the stormwater drainage from this site is conveyed. The existing topography for this 39 acre property flows from south to north and into an existing unnamed ditch at the northwest corner of the property. This ditch conveys stormwater under Weld County Road 6 via an existing culvert and flows in a northerly direction towards Little Dry Creek. The unnamed ditch terminates at Little Dry Creek approximately one mile north of Weld County Road 6. Little Dry Creek accepts the stormwater flow from the unnamed ditch and flows in a northeasterly direction towards the Platte River. The Frederick USGS Quadrangle Map has been included in Appendix A of this report. The proposed site is located in Zone C as shown on the FEMA Flood Insurance Rate Map (Panel Number 080266 0980 C). Zone C is defined as "areas of minimal flooding" and is outside of 100 - year floodplain areas. The FEMA Firm Map is also included in Appendix A of this report. A Historic Drainage Map is included in Appendix D of this report. This Historic Drainage Map includes one -foot existing contours and demonstrates the existing drainage patterns for the subject property. B. Sub -Basin Description As mentioned in the previous sections of this report, the existing drainage pattern for this site is from south to north with an average slope between 1%-2%. The on -site area drains into an unnamed ditch at the northwest corner of the site that then flows under Weld County Road 6 via an existing culvert. The existing drainage patterns for the site are indicated on the Historic Drainage Map that is included in Appendix D of this report. The majority of the drainage from the surrounding developments does not impact this site. As shown on the USGS Map in Appendix A, the area north of Weld County Road 6 drains towards the north, and therefore does not flow onto the proposed development. The Union Pacific Railroad right of way includes a 3 -foot to 10 -foot high berm adjacent to our site that prevents water from the east from flowing onto our site. The property to the south of this site drains in a southeasterly direction and does contribute any off -site flow onto the Tri-State property. This is demonstrated on the USGS Map in Appendix A and on the Historic Drainage Map in Appendix D of this report. The existing farm to the west of this site drains in a northerly direction to the unnamed ditch, and therefore also does not contribute any substantial off -site flow. Therefore, no special provisions need to be made to account for off -site flows with the development of this property. III. Drainage Design Criteria A. Development Criteria Reference and Constraints. According to discussions with Weld County Public Works staff, there are not any previous drainage studies available that influence the subject property. Drainage impacts downstream of the proposed site development will be minimized by a proposed on -site water quality and detention basin that will collect and detain developed flows and release runoff into the existing unnamed ditch at the historic Erie Substation Expansion: Preliminary Drainage Report 2 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 5 -year flow rate. Also, the proposed grading for the site has been designed to avoid any discharge into the existing East Branch Bull Canal, located on the south side of the developed site. B. Hydrological Criteria This drainage study followed the guidelines set forth in the Urban Storm Drainage Criteria Manuals and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals. Facilities on -site will be designed to safely convey runoff from the 10 -year and 100 -year rainfall events. The rainfall depth -duration -frequency maps from Urban Drainage (Figures RA -2, RA - 3 and RA -6) were utilized to obtain storm duration information for 5-, 10- and 100 -year, respectively. Peak runoff rates for the minor (10 -year) and major (100 -year) storm events were calculated using the Rational Method. Refer to Appendix B of this report for the detailed runoff calculations for both the historic and proposed conditions. The rational method is based on the following formula: Q=CxIxA where Q = Peak Discharge (cfs) C = Runoff Coefficient I = Rainfall Intensity (inches/hour) A = Drainage Area (acres) The proposed detention and water quality basin has been designed using "empirical equations" per Chapter 3.2.2. Empirical Equations for the Sizing of Onsite Detention Storage Volumes of the Urban Storm Drainage Manual (V. 2) and Chapter 4.4.2 Water Quality Capture Volume (WQCV) of the Urban Storm Drainage Manual (V. 3). Refer to Appendix C of this report for detailed calculations for the detention and water quality basin. C. Hydraulic Criteria The storm sewer culverts on this site were designed according to Section 8-11-40.2 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals. This section states that culverts are to be designed for both the 10 -year and 100 -year storm event based on a maximum culvert headwater to diameter ratio. This section requires a HW/D to be less than 1.0 for the 10 -year storm event and to be less than 1.5 for the 100 -year storm event. Culvert Master, Version 3.1 was used to analyze the proposed culverts in this drainage study. Appendix C of this report contains the detailed calculations for the proposed culvert sizing. The outlet type for the detention and water quality basin used for this project is the standard Urban Drainage water quality outlet box with a trash rack and steel perforated flow control plate. The trash rack and perforated flow control plate were designed per the requirements stated in Volume 3 of the Urban Storm Drainage Criteria Manual. The detention and water quality basin release rates were designed per Weld County requirements. Per Section 8-11-30.17 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, the release from the outlet box shall be designed for the flow developed from the 5 -year historic storm event. However, Weld County also has a maximum allowable unit release rate per acre of tributary area catchment for on -site detention facilities for the 5 -year storm event as shown in the Urban Drainage Table SO - 1. Table SO -1 indicates that for Hydrologic Soil Group C, the maximum allowable unit release rates are 0.17 cfs/acre for a 5 -year return period, which equals 1.29 cfs for the 7.60 acres disturbed for this development. Since the maximum allowable release rate is less than the historic 5 -year storm flow, the 1.29 cfs value was used for the maximum discharge out of the outlet box. The calculations Erie Substation Expansion: Preliminary Drainage Report 3 ••••••••••••••••••••••••••••••••••••••••••• for the outlet structure can be found in Appendix C of this report. In addition, Appendix D of this report includes an exhibit that shows the details for the outlet structure. The emergency spillway was designed per Section 8-11-40.16 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals. This section states that the detention pond shall contain an emergency spillway capable of conveying the 100 -year peak flow draining into the pond. It also requires a maximum spillway depth of 6 inches or less. Appendix C of this report includes calculations for the emergency spillway. In addition, Appendix D of this report includes an exhibit that shows the details for the emergency spillway. IV. Drainage Facility Design A. General Concept Drainage facilities within this site have been designed to safely convey runoff from the 10 -year and 100 -year frequency storm events in accordance with the regulations set forth in the Urban Storm Drainage Criteria Manuals and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals. The proposed drainage pattern for this site is typically from south to north, similar to the historic drainage patterns. Stormwater sheet flows off of the gravel pad and is directed into swales that run on both the west and east side of the Tri-State substation. The proposed swales then direct the stormwater flow into the proposed detention and water quality basin located on the north side of the site. The detention and water quality basin detains the proposed stormwater flow and then releases it into an existing unnamed ditch at the north end of the site, similar to the historic condition. See Section II.A of this report for discussions on where the stormwater goes after it leaves the Tri-State property. As previously discussed in Section Il.B of this report, there is no off -site drainage flowing onto this site that adversely affects the drainage for this development. Appendix A of this report includes a Vicinity Map, an NRCS Soils Map, a USGS Map, and a FEMA Firm Panel for the subject property. Appendix B and C of this report include various charts, tables, and figures from the Urban Storm Drainage Criteria Manual that supports the calculations included in those appendices. Appendix D of this report includes a Historic Drainage Map, a Proposed Drainage Map, and Water Quality Outlet Details for this project. B. Specific Details The site has been delineated into one historic drainage basin, which can by found on the Historic Drainage Map enclosed in Appendix D of this report. Basin A is 7.60 acres and slopes to the north at approximately 2.2% into the existing unnamed ditch. Basin A has a 5 -year runoff of 3.36 cfs, a 10 - year runoff of 5.9 cfs, and a 100 -year runoff of 17.4 cfs. For the purpose of this drainage study, the site has been divided into five on -site basins. Basin 1 consists of a portion of the existing Tri-State substation that flows into the proposed detention and water quality basin. Basin 1 is 0.43 acres in size and drains towards the proposed Culvert 1. The 10 -year and 100 -year runoff values are 0.6 cfs and 1.6 cfs, respectively. Basin 2 consists of a portion of existing land, existing gravel roadway, and part of the proposed gravel pad for the Tri-State Substation Expansion. This basin is 0.78 acres in size and drains toward Erie Substation Expansion: Preliminary Drainage Report 4 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • the Proposed Culvert 2. The 10 -year and 100 -year runoff values for this basin are 1.2 cfs and 2.9 cfs, respectively. Basin 3 is 1.61 acres in size and drains towards Culvert 3. Basin 3 consists of a portion of the proposed gravel pad and open space area for the Tri-State Substation Expansion. The 10 -year and 100 -year runoff values for this basin are 2.4 cfs and 6.0 cfs, respectively. Basin 4 consists of portions of the existing Tri-State substation and portions of the proposed gravel pad and open space areas for the Tri-State Substation Expansion. Basin 4 is 4.03 acres in size and drains directly into the proposed pond. A swale will be constructed along the western property of the site to direct flow from the west and south portions of the site to the on -site detention and water quality pond. The 10 -year and 100 -year runoff values are 5.5 cfs and 13.2 cfs, respectively. Basin 5 consists of the proposed detention and water quality pond and a portion of the proposed gravel pad and gravel access road for the Tri-State Substation Expansion. Basin 4 is 0.75 cres in size and drains directly into the proposed pond. The 10 -year and 100 -year runoff values for this basin are 2.0 cfs and 4.0 cfs, respectively. These five proposed drainage basins are all routed into the proposed detention and water quality basin located at the north end of the site. The total area for all of these basins is 7.60 acres and the total 10 -year and 100 -year runoff values are 10.8 cfs and 25.6 cfs, respectively. V. Conclusions A. Compliance with the Weld County CODE This preliminary drainage report is in compliance with the standards and requirements set forth in the Urban Storm Drainage Criteria Manuals, Volumes 1-3 and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1, 2 and 3 dated October, 2006. B. Drainage Concept As stated above, this drainage report was designed per the requirements outlined in the Urban Storm Drainage Criteria Manuals, Volumes 1-3 and the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals, Volumes 1, 2 and 3. The storm drain facilities located within this project were designed to convey the 10 -year and 100 -year storm events safely through the site and into the existing downstream drainageway. The proposed detention and water quality pond that is located on the north side of the proposed development was designed to reduce peak flows below the maximum allowable flows required per Weld County. The proposed pond also contains a water quality component that will ensure that "clean" water is discharged downstream. As demonstrated in this report, the proposed development should not have a negative impact on downstream developments. Erie Substation Expansion: Preliminary Drainage Report 5 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • C. References Flood Insurance Rate Map Weld County, Colorado, Unincorporated Area, Panel No. 0802660980C, dated September 28, 1982. Soil Survey of Weld County, Colorado, Southern Part U.S. Department of Agriculture, National Resources Conservation Service, Version 9, dated February 11, 2008. Frederick Quadrangle USGS Map U.S. Geological Survey, 1994 Urban Storm Drainage Criteria Manual Volume 1-3 Wright Water Engineers Inc., dated June 2001. Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals Volume 1, 2 and 3 Weld County Public Works Department, dated October 2006. Erie Substation Expansion: Preliminary Drainage Report 6 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • VI. Appendices Appendix A: Maps i. Vicinity Map ii. NRCS Soils Map iii. USGS Map iv. FEMA Firm Panel Appendix B: Hydrologic Computations i. Urban Drainage Rainfall Depth -Duration -Frequency Maps: RA -2, RA -3, and RA -6 ii. Urban Drainage Tables RO-3 and RO-5 iii. Urban Drainage Figure RO-1 iv. Historic Drainage Basin Calculations (Impervious and Runoff Coefficient Calculations, Standard Forms SF -2 and SF -3) v. Proposed Drainage Basin Calculations (Impervious and Runoff Coefficient Calculations, Standard Forms SF -2 and SF -3) Appendix C: Hydraulic Computations i. Urban Drainage Figure HS -20 ii. Urban Drainage Figure SQ-2 iii. Culvert Calculations iv. Swale Calculations v. Rip Rap Calculations vi. Detention and Water Quality Basin Volume Calculations vii. Water Quality Outlet Calculations viii. Emergency Spillway Calculations Appendix D: Exhibits i. Historic Drainage Map ii. Proposed Drainage Map iii. Water Quality Outlet Details Erie Substation Expansion: Preliminary Drainage Report 6 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 APPENDIX A MAPS • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • JOHN C. & CAROLYN S. BROOICI AN JAMES IRENFROW 26 ERIE SUB -STATION EXPANSION MU. CANAL SAND LAND PROPERTIES, LLC & SAND LAND, INC. '25 RECREATIONAL STO SOLUTIONS, SUSAN E TALBOT GST TRUST 64"rManhardim coNsuLTiNc /442 South Tucson Way. Suite 190-A. Centennial. CO 80112 ph:303.708.0500 fx 303.708 0400 manhard.com Civil Engineers • Surveyors • Water Resource Engineers • Water & Wastewater Engineers Construction Managers • Environmental Scientists • Landscape Architects • Planners WELD COUNTY, COLORADO VICINITY MAP PROJ. MGR.: KPB DRAWN BY: DATE: SCALE: MAL 01-23-09 1 TSGERC SHEET OF 1 071217 © 2008 ALL RIGHTS RESERVED Updated By P: \Tsgerc\documents\StormWater Reports\Preliminary_04-15-2009\Vicinity Map.dwg 0 z 3 0 co (N 0 • • • • • L .L9 .901 • • • • • • • • • • �c • O N C Co Ia X W O 0) .` w • • O i S S • • 2 • • • • • • • • • .6£ .LS .901 • • • • 0,01£„ 0960£,9 0980£„ 0080£,9 OLLO£vv 0C90£U4 0 5 OPOI£9v 096.£99 • 099.£99 009sEPP • oat'£vv 0v9,£vv CD .4- 0 1 ..L IS .90L04 O LO 7_ 0) Cl_ 8 I S S 8 8 S 0 8 5S 13,550 if printed on A size (8.5" x 11" In C 0 0 0 O O Z -< ..6£ .LS ;70i a) N O u) Z > CO - 0) oa co �g To (d 8 CO. 8 k-� 20 co zo g I • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • t co N L O O co c �- O O N Oco x C c O O co 4,74 OI) o `w O ', cn^ U_ O) O —2- -o • • NFORMATION a 2 MAP LEGEND Map Scale: 1:3,550 if printed on A size (8.5" x 11") sheet. Area of Interest (AOI) The soil surveys that comprise your AOI were mapped at 1:24,000. Area of Interest (AOI) a co E a) > 8 °v) 7 a. O oo o O a) 4co c a) z N N a ccoo O , Z E U . `� w oz r a) LI n) L-03 2 a)cp c 0 z--__.0 o 18 ri.N a) �: g t F - o 12D cv cr a) n z Li t >,0 N a . > c �- O c (Dr cn >, 2 co a) 73 2 CAN w. co co 0 2 0 a E c°RU Soil Map Units ❑Io N C sr 0 U) w O U) co co to D V a) w t (1) O Ce Z a a) L O c a) C) 0 O a. v) s I - O a) -o U) a co V C O 0 s t co a E a) L 7 O c co O O -oO CO N o r 0 U ID CD Z LL C O) O O U - Ti) o Date(s) aerial images were photographed: O) C a .. r c o u) z c c 0) E Y a) O Oo t o a) a) 0 _C O E N O a) c L N c o Q co a 0 fin E43 a) C .a) - O N O C (t- 8 _ o) aa))�c a) E cv E � °.o O co Co co O IC O C a CD [D U J O Z ❑ ❑❑ litical Features • Streams and Canals Transportation U, co Interstate Highways Local Roads • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Hydrologic Soil Group —Weld County, Colorado, outhern Part • Erie Substation Expansion Hydrologic Soil Group Hydrologic Soil Group— Summary by Map Unit — Weld County, Colorado, Southern Part Map unit symbol Map unit name Rating Acres in AO1 Percent of AOI 66 Ulm clay loam, 0 to 3 percent slopes C 38.2 92.8% 79 Weld loam, 1 to 3 percent slopes C 3.0 7.2% Totals for Area of Interest 41.1 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (ND, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition USDA a Natural Resources Conservation Service Web Soil Survey 2.1 National Cooperative Soil Survey 4/15/2009 Page 3 of 4 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • UNTIED STATES , TWEM OF THE QfTt7il)R ,It N 7 P 40437 0' 0A 1,., I- nc u MAINLY Ufa J '%=1:: 171 awa...a.1w .. •1r•wlaudar S•6•at. 's--. M I•AdIatmpI1 a alSaatoa• t•• fotad U• a•aa4rsn.ww aa•ada n- ad+M •II•Iw Ar..• al•aI im a••d a.a•aiSale sae tit,_ If2nwl as 11P•d age a1 Cans Gas Saul a• 21110 alIaaa Oaf/ we•1•••*al w Sot a Teri. M aY SIMa 77.1• IMO • Meta .• - ona�dl•I.1. aunt *MS SW* man au lea •a1a abwar •.a1Y law so tan 1ISa It a•+a SA a I17 A f v MO Mu as a as lea -CU MRS s ral 9r P r a 1 • o a **A_ Ma WI =•et SOU 1 -MOOD • a • •0/IOR anaaa. q ►wr Won alla arra O.1, 1 0. 11 • w n aII.aI AMINO Iaa as WV all t1 wall .a COMP Weal l0. WI Or Y I IPECtall I41w•Ea. RI•Rl 0wa•.= 1.7Ta Oa .4/01. ` fls 220.2 • 101x. was man OM W nMo3 a nasals 0• Marl, IMEDancK WAXMAN= en= PS SUITE -- (TOPOOMMQ •e in an • to a�iaiw Y-lun•wlwM- taw MING 0 t�w�•_y�aila • w•.� Igl•a•saaar — r RWERICl\ OD ora Ire law an* a r sr IIt r • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • s • IATE SCALE 0 1000 FEET a E • W t "' U_ 5 90 Z O O �y.• I' 48 OO1 N a2 <nal ' W il e : ' ~ 'M1 W O[ ni :lei q 0WO S C: d0 - _1FNME �Gi W ot a i gcniiZs • O W` ci ;�E i i !I•_8 i • V { g g' 1911 1131 _O u i UU `i �.ifi } Wig • Y 11E21 = Y../�. rOtil -, 19 ZONE C / / O M ...../ E-7 ,_,-, c, ye k P p �f� N ... o In CV zm a U) CC CD N re....•-•.,,.. _.0.07 N � �- cD N ••••••••••••••••••••••••••••••••••••••••••• APPENDIX B HYDROLOGIC COMPUTATIONS • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • RAINFALL Figure RA -2 ---Rainfall Depth -Duration -Frequency: 5 -Year, 1 -Hour Rainfall RA -14 DRAINAGE CRITERIA MANUAL (V. 1) ADAMS ARAPAHOE 01/2004 Urban Drainage and Flood Control District • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • DRAINAGE CRITERIA MANUAL (V. 1) Figure RA -3 —Rainfall Depth -Duration -Frequency: 10 -Year, 1 -Hour Rainfall CONFER • Rev. 01/2004 Urban Drainage and Flood Control District SECALIA PAHOE PAP CP • AHAPAH0E ELBERT RAINFALL RA -15 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • RAINFALL Figure RA -6 —Rainfall Depth -Duration -Frequency: 100 -Year, 1 -Hour Rainfall RA -18 P 89 w� Z.AP 68 A DRAINAGE CRITERIA MANUAL (V. 1) PAPAHOE II BERT 01/2004 Urban Drainage and Flood Control District • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • DRAINAGE CRITERIA MANUAL (V. 1) RUNOFF Table RO-3—Recommended Percentage Imperviousness Values Land Use or Surface Characteristics Percentage Imperviousness Business: Commercial areas 95 Neighborhood areas 85 Residential: Single-family * Multi -unit (detached) 60 Multi -unit (attached) 75 Half -acre lot or larger * Apartments 80 Industrial: Light areas 80 Heavy areas 90 Parks, cemeteries 5 Playgrounds 10 Schools 50 Railroad yard areas 15 Undeveloped Areas: Historic flow analysis 2 Greenbelts, agricultural 2 Off -site flow analysis (when land use not defined) 45 Streets: Paved 100 Gravel (packed) 40 Drive and walks 90 Roofs 90 Lawns, sandy soil 0 Lawns, clayey soil 0 * See Figures RO-3 through RO-5 for percentage imperviousness. CA = KA + (1.31i3 —1.44i2 +1.135i — 0.12) for CA ≥ 0, otherwise CA= 0 (RO-6) CCD = KCo + (0.858i3 — 0.786i2 + 0.774i+ 0.04) (RO-7) CB =(CA +Cc0)12 2007-01 Urban Drainage and Flood Control District RO-9 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • DRAINAGE CRITERIA MANUAL (V. 1) Table RO-5-- Runoff Coefficients, C RUNOFF Percentage Imperviousness Type C and D NRCS Hydrologic Soil Groups 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr 0% 0.04 0.15 0.25 0.37 0.44 0.50 5% 0.08 0.18 0.28 0.39 0.46 0.52 10% 0.11 0.21 0.30 0.41 0.47 0.53 15% 0.14 0.24 0.32 0.43 0.49 0.54 20% 0.17 0.26 0.34 0.44 0.50 0.55 25% 0.20 0.28 0.36 0.46 0.51 0.56 30% 0.22 0.30 0.38 0.47 0.52 0.57 35% 0.25 0.33 0.40 0.48 0.53 0.57 40% 0.28 0.35 0.42 0.50 0.54 0.58 45% 0.31 0.37 0.44 0.51 0.55 0.59 50% 0.34 0.40 0.46 0.53 0.57 0.60 55% 0.37 0.43 0.48 0.55 0.58 0.62 60% 0.41 0.46 0.51 0.57 0.60 0.63 65% 0.45 0.49 0.54 0.59 0.62 0.65 70% 0.49 0.53 0.57 0.62 0.65 0.68 75% 0.54 0.58 0.62 0.66 0.68 0.71 80% 0.60 0.63 0.66 0.70 0.72 0.74 85% 0.66 0.68 0.71 0.75 0.77 0.79 90% 0.73 0.75 0.77 0.80 0.82 0.83 95% 0.80 0.82 0.84 0.87 0.88 0.89 100% 0.89 0.90 0.92 0.94 0.95 0.96 TYPE B NRCS HYDROLOGIC SOILS GROUP 0% 0.02 0.08 0.15 0.25 0.30 0.35 5% 0.04 0.10 0.19 0.28 0.33 0.38 10% 0.06 0.14 0.22 0.31 0.36 0.40 15% 0.08 0.17 0.25 0.33 0.38 0.42 20% 0.12 0.20 0.27 0.35 0.40 0.44 25% 0.15 0.22 0.30 0.37 0.41 0.46 30% 0.18 0.25 0.32 0.39 0.43 0.47 35% 0.20 0.27 0.34 0.41 0.44 0.48 40% 0.23 0.30 0.36 0.42 0.46 0.50 45% 0.26 0.32 0.38 0.44 0.48 0.51 50% 0.29 0.35 0.40 0.46 0.49 0.52 55% 0.33 0.38 0.43 0.48 0.51 0.54 60% 0.37 0.41 0.46 0.51 0.54 0.56 65% 0.41 0.45 0.49 0.54 0.57 0.59 70% 0.45 0.49 0.53 0.58 0.60 0.62 75% 0.51 0.54 0.58 0.62 0.64 0.66 80% 0.57 0.59 0.63 0.66 0.68 0.70 85% 0.63 0.66 0.69 0.72 0.73 0.75 90% 0.71 0.73 0.75 0.78 0.80 0.81 95% 0.79 0.81 0.83 0.85 0.87 0.88 100% 0.89 0.90 0.92 0.94 0.95 0.96 2007-01 Urban Drainage and Flood Control District RO-11 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • DRAINAGE CRITERIA MANUAL (V. 1) WATERCOURSE SLOPE IN PERCENT 50 30 20 10 3 2 1 .5 RUNOFF �VTrE+ `��w P �v s • 3 CO , • 0= s• .• 3k b 4W III v at `J a 0 r 4Q VP 4y� C°J_� a. y ' • v 3 V o W 4� i , yQt iot •• bb AL (ice 3 O °e �• W� A. C 4 4t br I Q• Syr 3 0 .1 .2 .3 .5 1 2 3 5 VELOCITY IN FEET PER SECOND 10 20 Figure RO-1—Estimate of Average Overland Flow Velocity for Use With the Rational Formula 06/2002 Urban Drainage and Flood Control District RO-13 ••••••••••••••••••••••••••••••••••••••••••• RUNOFF COEFFICIENTS AND IMPERVIOUSNESS Erie Substation Expansion Project: Erie Substation Expansion Calculated by: MAL Date April 15, 2009 JOB NO: TSGERC/ 071217 Revised by: Date Land Use Runoff Coeff. Impervious Undeveloped Gravel Lawns, clayey soils Pond 5-yr 10-yr 100-yr 0.16 0.26 0.51 0.35 0.42 0.58 0.15 0.25 0.50 0.90 0.92 0.96 0.02 0.40 0.00 1.00 Basin No Land Use Historic A Undeveloped Gravel Total 1 Proposed Lawns, clayey soils Gravel Total 2 Lawns, clayey soils Gravel Total 3 Lawns, clayey soils Gravel Area (AC) Area`Coeff. 5-yrj 10-yrI 100-yr Composite Runoff Coeff. 5-yr I 10-yr I 100-yr 6.07 0.97 1.58 3.10 1.53 0.54 0.64 0.89 7.60 1.51 2.22 3.98 0.20 0.29 0.52 0.20 0.03 0.05 0.10 0.23 0.08 0.10 0.13 0.43 0.11 0.15 0.23 0.26 0.34 0.54 0.26 0.04 0.07 0.13 0.52 0.18 0.22 0.30 0.78 0.22 0.28 0.43 0.28 0.36 0.55 0.45 0.07 0.11 0.23 1.16 0.41 0.49 0.67 1.61 0.47 0.60 0.90 0.29 0.37 0.56 Total 4 Lawns, clayey soils Gravel 0.82 0.12 0.21 0.41 3.21 1.12 4.03 1.25 1.55 2.27 0.31 0.39 0.56 1.35 1.86 Total 5 Pond Lawns, clayey soils Gravel 0.37 0.12 0.26 0.75 0.44 0.48 0.57 0.59 0.64 0.75 0.33 0.02 0.09 0.34 0.03 0.11 0.36 0.06 0.15 Total Proposed Total (ac) 7.60 Detention Pond Imperviousness Lawns, clayey soils Gravel Pond 1.85 5.38 0.37 7.60 ac 33.2% ••••••••••••••••••••••••••••••••••••••••••• _ Z Yn • NO m N g Z • O W U U Q U O • Q O (- W rnw2 I- TSGERC/ 071217 0 N C Erie Substation Ex April 15, 2009 • w < Q ❑ ❑ W D N O > c ¢w 0. 0CC REMARKS u H J C z E LL rn N TRAVEL TIME (Tt) - (PAVEMENT/CURB & GUTTER) Cups) O 'EL will O 13AVtl1 IsdU Al. o IOO13A O (v.) 33015 Ia)' HJON3l MOli TRAVEL TIME (Tt) - (GRASS SWALE) ("lull 7.0 11. 3531 13AVa1 MU Al LL? I0Ol3A r -43 (.) 3d015 N IH)' HION31 V M014 f0 INITIAL/OVERLAND TIME (Ti) (NIW) W LLW1 'a1 O 1VIIINI N 0 110 34013 N WI' 0 HSON31 M MO1i SUB -BASIN DATA (5005) v 'v3av L 091 50 '1N313 0 ry 145300 iiONOtl p NOUN NOIS30 Q V3UV re m LL 8 J N X U > p u u z R ••••••••••••••••••••••••••••••••••••••••••• Z C7 • in Z W w M G D < LL2L M N W U • O Z LL. • W O < z• W g t m - O co • o O = ce O� I- y JOB NO: TSGERC/ 071217 Erie Substation Ex DESIGN STORM: 5 -year Manning's n -value =0.013 April 15. 2009 g REMARKS N TRAVEL TIME (use) awl_ 'snag ry (j) q]6uai (set) R]polaA (%) adolS STORM SEWER (943) moli uorsaQ (sP) Ifni) (0) axis ]uaw6as STREET/INLET (slo) ianoNiea y (slo) Apedea]ail R io ]aai]s -- No) mold u61sea ;Bpi 7- (sio) mold laseS a DIRECT RUNOFF (sP) c° m co O'gouna pwlo - ei (swov) V.a C L7). (q/u!) I'Rllsua]uI N "'N a n N ']UBIOIJJaO'J ijOUn�J ` 6 a) Cup) of v N 0 (oe) can/ u? z plod ublsao E.T N— O 1-• Q U c— IL it um O ❑ Co a P1 = 1.36 (5 -Year 1 hour rainfall) ••••••••••••••••••••••••••••••••••••••••••• U z Q LL m c0 Z co 4 Q • c • Z O y co Z U CO w Wcc CD 5 ww I— 0 a N O W= Q W Z2 rttI J re Z O 0 • Q • ce O H JOB NO: TSGERC/ 071217 DESIGN STORM: 10 -year Manning's n -value =0.013 April 15, 2009 w ui H H O 0 0 .C m Erie Substation Ex it m O } co J O w 7 N O -J> • < w 0- O K REMARKS N TRAVEL TIME (ulw) awll wen. - (y) )(l6ual in (sd;) Ap ooleA (%) adolg STORM SEWER (s;o) mold u6lsa4 (sio)Ihnt (u) azls a luaw6es ^ I STREET/INLET (943) lano%JeQ V (s;o) A1aede3lalul ;- JO lawns (si0) p mold u6lsad lalul = (slo) mold lawns DIRECT RUNOFF (slo) O ;)ouna loana m m - vi N (saroy) yq E N (N Uy/ul)I'plsualul (7)- N n m LT, N 'IUOIOld;aO'J;;OUOZ{ " O 0) ('ulw) of ;I: N (oe) ewy 0 n I IDENTIFICATION luiOd u6isap (V N- C Q •N m Pi = 1.62 (10 -Year 1 hour rainfall) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Z O Z W w N M C D Quigo m m u o O COniC Z • 0 OO gW w m Q Z 2 Oi-no = O (— co JOB NO: TSGERC/ 071217 Erie Substation Ex DESIGN STORM: 100 -year Manning's n -value =0.013 April 15, 2009 m o .. w Q m w 8U - i> w O U CC N C Q w tr TRAVEL TIME N (ulw) awl laneil O N (a) yl6uai m (soli) 6)polaA (°/a) edolS STORM SEWER (sjo) mold uaisaa (sjo) Ilnjo (w) az!S ;uaw6as STREET/INLET (sp) JanoAlleo N (sp) Alpedeolalul JO ;GODS (sp) mold u6lsad jam s (sp) mold laawlS O) DIRECT RUNOFF (sjo) 0 'J4ouna loenp v, N- (sajoy) V.3 (Jy/ul) I'6llsua;ul 0 0 yuepy;aoo gounld N N O (' ulw) o j QJ N- N (oe) ealy of O N- IDENTIFICATION lulod u6lsap C 0 N m Q P, = 2.67 (100 -Year 1 hour rainfall) ••••••••••••••••••••••••••••••••••••••••••• U) z QNO v 2 Z O W u- < U 0< ayw a. 7SGERC/ 071217 0 z O 0 Erie Substation Ex Aod[15. 2009 Ill Ul 4 O O REMARKS u 12.3 16.4 I- s z t • I, co r r N. O LL Tc CHECK (urbanized basins) Cal • Oiu l) r- co. M V O =a1 ' Ncc; N w nwIww .- 1- 1u) H10N31 1V101 303 315 0 7, 351 TRAVEL TIME (Tt) - (PAVEMENT/CURB & GUTTER) Iona)'0 '1131M1OO 0 0 0 0 l3AYL1 000 (sd))A. 00000 13013A 00000 1x) 3dOlS 1L)' H1ON31 MOIi TRAVEL TIME (Tt) - (GRASS SWALE) lulw) O O If) N n 113VIII 13AYa1ON�� O ($(4) All I3O13A 0 ly 0 .- CO, CO, N la) o 0 0 0 3.401$ Ul V (0 M r- If) r 8111' N- CO r 810th V 10 Ill .- U) MOl O INITIAL/OVERLAND TIME (Ti) (NIW) 4— OV000 11'3WI1 0) P) IIl O O 1YI11N1 ' .— r N 1x1 3.401$ 2.7% 3.2% M n c•7 - o 1L)' 00 11 0 O H1ON3l 0 f0 V Q O MOW M 1— NCO CO SUB -BASIN DATA (suas) 0.43 0.78 IL!O N Y'Y3aV - V O S3 1N '313 (O 00 N N O) .— N C') 0) I() .4.40013 C 6 GO NOW/ N01530 v3av •-• NC') V I() 6 K a r 6_ UO c F, 0 O H J 7 x Z o U J 0 x T u m La O J6 0 II II U z ••••••••••••••••••••••••••••••••••••••••••• z Z W w Q M p S It CO 2w IJ maw } Q 11. ZO®O Q LL 0 CC C91= - p Q — Z O N p O a O U) JOB NO: TSGERC/ 071217 h w Erie Substation Ex DESIGN STORM: 10 -YEAR Manning's n -value =0.013 m 0 LO as o �. REMARKS 1 (21) To design point 2 To design point 3 To design point 5 To design point 5 I TRAVEL TIME (ulw) awil ianejl a " N o N o N 0 (sd)) AliooIeA m o N In M C'J (u) 416uai m 2- M TOTAL RUNOFF STORM SEWER (sagoul) anS adid c- in -- r Ln r r N (%) adois .o I 0 in 0 In Lig; Mold u6isap )3 Io 0 o � r ',- v (slo) O 'young Ie)oj = N r r v o° 0 (sang) V.p 0.43 M O (D o M (J4/u) I'Allsualui g —. r V o V in co ('uiw)Jj °' O ci co c‘i V co DIRECT RUNOFF (s70) 0 'younu peJlp m CON "" 0 r 2.4 no Ln N (senV) V.0 4 ^ 7 000.-0 W ry 0 co U) in 0 v, WO I'Al!sualul 3 r — v r v o v In en M 'a p ')ua19f}0Op young N co " 0 M 0 M 0 M 0 CDD 0 ('ulw)oj N- r a° ! co N V (D I� O (Oe) BoJy M m '7 O co h o ID r f`0 O V in I - 0 )UIOd u6lsap c'r N M Tr In CH Wseg r N Co '7 in P, = 1.62 (10 -Year 1 hour rainfall) ••••••••••••••••••••••••••••••••••••••••••• z co z QW M O D CO LL 2 o • ;• v.N z0 LL 0 CC Clot • Q OFQ-oo O y 2 ce te a O I- JOB NO. TSGERC/ 071217 0 0 Erie Substation Ex DESIGN STORM: 100 -YEAR Manning's n -value =0.013 April 15. 2009 W W F I- 0 0 REMARKS (21) To design point 2 To design point 3 To design point 5 To design point 5 TRAVEL TIME (uIw) aw!1 howl o r) v o r O (N O (sdj) Al!poIOA .6 'n M o to 0) to (u) 416ual m 3 M 3 TOTAL RUNOFF STORM SEWER (salpu!) az!g adId p in — r L r r N (%) adO1g t° o if ILXD? mold u6!sad n CO = r to v ? or (SJp) 17 'young 12101 N =- up V 7, 0 N (saaV) V.3 0.67 4.40 0qN!) I 'Rl!sualuI g N. ro co co OD ui (u1w) a a O) r Cr) 7 c6 DIRECT RUNOFF (SJO) O 'y0unjj papa m co " r W N o (6 N 4.0 (Baby)V.0 Co "N O co 'Cr O o O 1- N N r- I°. O G4/ui 1'Al!sualu1 _ co -° 6 co co co co op 6 o N- 3 •lual0!yeo3 young n — 6 to 6 to 6 16 6 n 6 (w!w)oj N- ' co co V ro h o (oe) Bea,' c.e) M' 6 co N O ro r r co V up N- 0 lu!Od u6!sad 67 r N Co v to ❑1 u!Se9 ,. r N CO V to P, = 2.67 (100 -Year 1 hour rainfall) ••••••••••••••••••••••••••••••••••••••••••• APPENDIX C HYDRAULIC COMPUTATIONS ib • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • DRAINAGE CRITERIA MANUAL (V. 2) 30 25 0±3 20 ii tv E 15 C o_ C C, 10 C 5 2 3 4 5 6 7 8 Storm Sewer Diameter, D, or Height, H, in ft. 1 HYDRAULIC STRUCTURES Figure HS -20c —Low Tailwater Riprap Basins for Storm Sewer Pipe Outlets— Riprap Selection Chart for Low Tailwater Basin at Pipe Outlet (Stevens and Urbonas 1996) Rev. 2008-04 Urban Drainage 8 Flood Control District HS -83 ••••••••••••••••••••••••••••••••••••••••••• DRAINAGE CRITERIA MANUAL (V. 3) 0.50— - 0.45 - 0.40- „ 0.35 -- 0.30 - w L 0.25 -- 0.20 d 0A5 0.10 - 0.05 0.00 WQCVa'(0.91i 3 -1.19,2 +0 780 6 -hr drain time a = 0.7 12 -hr drain time a = 0.8 24 -hr drain time a = 0.9 40 -hr drain time a = 1.0 r STORMWATER QUALITY MANAGEMENT 40 -hour Drain Tim 24 -hour Drain Tim 6 -hour Drain Time 12 -hour Drain Time H 0 a1 0.2 03 0.4 0 5 0.6 0 7 0 8 0.9 Total Imperviousness Ratio (i =/,,,,/100) Figure SQ-2—Water Quality Capture Volume (WQCV), 80th Percentile Runoff Event 10-2005 Urban Drainage and Flood Control District SQ-25 • • • • • • • • • • • • • • • • • • • • ••••••••••••••••••••••• Culvert Calculator Report Culvert 1-10yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elevi Inlet Control HW Elev. Outlet Control HW Elev. 5,143.95 ft 5,143.13 ft 5,143.11 ft 5,143.13 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 0.34 0.60 cfs 5,142.43 ft Outlet Control Grades Upstream Invert Length 5,142.70 ft 54.00 ft Downstream Invert Constructed Slope 5,142.43 ft 0.005000 ftfft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcritical 2.62 ft/s Depth. Downstream Normal Depth Critical Depth Critical Slope 0.30 ft 0.31 ft 0.30 ft 0.005257 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 15 inch 1 Mannings Coefficient Span Rise 0.013 1.25 ft 1.25 ft Outlet Control Properties Outlet Control HW Elev. Ke 5,143.13 ft Upstream Velocity Head 0.20 Entrance Loss 0.10 ft 0.02 ft Inlet Control Properties Inlet Control HW Elev. 5,143.11 ft Inlet Type Beveled ring, 33.7" bevels K 0.00180 M 2.50000 C 0.02430 Y 0.83000 Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 1.2 ft2 3 B 1 p:\...\preliminary_04-15-2009\tsgerc.cvm Manhard Consulting Project Engineer: Administrator CulvertMaster v3.1 (03.01.010.00] 04/17/09 07:59:45 AM3entley Systems. Inc. Haestad Methods Solution Center Watertown, CT 06795 USA +1.203-755-1666 Page 1 of 1 ••••••••••••••••••••••••••••••••••••••••••• Culvert Calculator Report Culvert 2-10yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elev, Inlet Control HW Elev. Outlet Control HW Elev. 5,140.48 ft 5,139.98 ft 5,139.95 ft 5,139.98 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 0.60 1.70 cfs 5,139.04 ft Outlet Control Grades Upstream Invert Length 5,139.23 ft 39.00 ft Downstream Invert Constructed Slope 5,139.04 ft 0.005077 ft/ft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcritical 3.54 ft's Depth, Downstream Normal Depth Critical Depth Critical Slope 0.52 ft 0.53 ft 0.52 ft 0.005380 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 15 inch 1 Mannings Coefficient Span Rise 0.013 1.25 ft 1.25 ft Outlet Control Properties Outlet Control NW Elev. Ke 5,139.98 ft Upstream Velocity Head 0.20 Entrance Loss 0.19 ft 0.04 ft Inlet Control Properties Inlet Control NW Elev. 5,139.95 Inlet Type Beveled ring, 33.7° bevels K 0.00180 M 2.50000 C 0.02430 Y 0.83000 ft Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 1.2 ft2 3 B 1 p:\...\preliminary_04-15-2009\tsgerc.cvm Manhard Consulting 04/17/09 08:01:11 AABentley Systems, Inc Haestad Methods Solution Center Watertown, CT 06795 USA Project Engineer: Administrator CulvertMaster v3.1 [03.01.010.001 +1-203-755-1666 Page 1 of 1 • • • • • • • • • • • • • • • • • • • • • •••••••••••••••••••••• Culvert Calculator Report Culvert 3-10yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elev; Inlet Control HW Elev. Outlet Control HW Elev. 5,135.75 ft 5,135.40 ft 5,135.34 ft 5,135.40 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 0.61 4.10 cfs 5,134.00 ft Entrance Control Grades Upstream Invert Length 5,134.32 ft 64.00 ft Downstream Invert Constructed Slope 5,134.00 ft 0.005000 ft/ft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream S2 Steep Supercritical 4.30 fUs Depth, Downstream Normal Depth Critical Depth Critical Slope 0.73 ft 0.73 ft 0.74 ft 0.004829 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 21 inch 1 Mannings Coefficient Span Rise 0.013 1.75 ft 1.75 ft Outlet Control Properties Outlet Control HW Elev. Ke 5,135.40 ft Upstream Velocity Head 0.20 Entrance Loss 0.28 ft 0.06 ft Inlet Control Properties Inlet Control HW Elev. 5,135.34 ft Inlet Type Beveled ring, 33.7' bevels K 0.00180 M 2.50000 C 0.02430 Y 0.83000 Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 2.4 ft2 3 B 1 p:\...\preliminary_04-15-2009\tsgerc.cvm 04/17/09 08:02:507U6entley Systems, Inc Manhard Consulting Project Engineer: Administrator CUIvertMaster v3.1 [03.01.010.001 Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 ••••••••••••••••••••••••••••••••••••••••••• Culvert Calculator Report Culvert 1-100yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elevi Inlet Control HW Elev. Outlet Control HW Elev. 5,144.58 ft 5,143.43 ft 5,143.39 ft 5,143.43 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 0.58 1.60 cfs 5,142.43 It Outlet Control Grades Upstream Invert Length 5,142.70 ft 54.00 ft Downstream Invert Constructed Slope 5,142.43 ft 0.005000 ft/ft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcritical 3.48 ft/s Depth, Downstream Normal Depth Critical Depth Critical Slope 0.50 ft 0.51 ft 0.50 ft 0.005343 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 15 inch 1 Mannings Coefficient Span Rise 0.013 1.25 ft 1.25 ft Outlet Control Properties Outlet Control HW Elev. Ke 5,143.43 ft Upstream Velocity Head 0.20 Entrance Loss 0.18 ft 0.04 ft Inlet Control Properties Inlet Control HW Elev. 5,143.39 Inlet Type Beveled ring, 33.7" bevels K M C Y 0.00180 2.50000 0.02430 0.83000 ft Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 1.2 ft2 3 B 1 p:\...\prelim inary_04-15-2009\tsgerc. cvm 04/17/09 09:00:55 AABentley Systems. Inc Manhard Consulting Project Engineer: Administrator CulvertMaster v3.1 [03.01.010.00] Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 Culvert Calculator Report Culvert 2-100yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elev: Inlet Control HW Elev. Outlet Control HW Elev. 5.141.11 ft 5,140.57 ft 5,140.52 ft 5,140.57 ft Headwater Depth/Height Discharge Tailwa ter Elevation Control Type 1.07 4.50 cfs 5,139.04 ft Outlet Control Grades Upstream Invert Length 5,139.23 ft 39 00 ft Downstream Invert Constructed Slope 5,139.04 ft 0.005077 ft/ft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcritical 5.00 ft/s Depth, Downstream Normal Depth Critical Depth Critical Slope 0.86 ft 1.00 ft 0.86 ft 0.007252 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 15 inch 1 Mannings Coefficient Span Rise 0.013 1.25 ft 1.25 ft Outlet Control Properties Outlet Control HW Elev. Ke 5,140.57 ft Upstream Velocity Head 0.20 Entrance Loss 0.30 ft 0.06 ft Inlet Control Properties Inlet Control HW Elev. 5,140.52 ft Inlet Type Beveled ring, 33.7° bevels K 0.00180 M 2.50000 C 0.02430 Y 0.83000 Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 1.2 f12 3 B 1 Project Engineer: Administrator CulvertMaster v3.1 [03.01.010.00) Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 p:\...\prel i m ina ry_04-15-2009\tsgerc. cvm 04/17/09 08:00:42 AABentley Systems, Inc. Manhard Consulting ••••••••••••••••••••••••••••••••••••••••••• Culvert Calculator Report Culvert 3-100yr Solve For: Headwater Elevation Culvert Summary Allowable HW Elevation Computed Headwater Elev; Inlet Control HW Elev. Outlet Control HW Elev. 5,136.95 ft 5,136.17 ft 5,136.12 ft 5,136.17 ft Headwater Depth/Height Discharge Tailwater Elevation Control Type 1.06 10.40 cfs 5,134.00 ft Outlet Control Grades Upstream Invert Length 5,134.32 ft 64.00 ft Downstream Invert Constructed Slope 5,134.00 ft 0.005000 ft/ft Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream M2 Mild Subcritical 5.91 fUs Depth, Downstream Normal Depth Critical Depth Critical Slope 1.20 ft 1.33 ft 1.20 ft 0.006469 ft/ft Section Section Shape Section Material Section Size Number Sections Circular Concrete 21 inch 1 Mannings Coefficient Span Rise 0.013 1.75 ft 1.75 ft Outlet Control Properties Outlet Control HW Elev. Ke 5,136.17 ft Upstream Velocity Head 0.20 Entrance Loss 0.44 ft 0.09 ft Inlet Control Properties Inlet Control HW Elev. 5,136.12 Inlet Type Beveled ring, 33.r bevels K 0.00160 M 2.50000 C 0.02430 Y 0.83000 ft Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form Unsubmerged 2.4 ft2 3 B 1 p:\..\prel iminary_04-15-2009\tsgerc.cvm 04/17/09 08:01:51 At.Bentley Systems. Inc Manhard Consulting Project Engineer: Administrator CulvertMaster v3.1 [03.01.010.00] Haestad Methods Solution Center Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • WEST SWALE FLOW CAPACITY Project Description Friction Method Solve For Input Data Roughness Coefficient Channel Slope Normal Depth Left Side Slope Right Side Slope Bottom Width Results Discharge Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow Type GVF Input Data Downstream Depth Length Number Of Steps GVF Output Data Upstream Depth Profile Description Profile Headloss Downstream Velocity Upstream Velocity Normal Depth Critical Depth Channel Slope Critical Slope Manning Formula Discharge Subcritical 0.050 0.01500 ft/ft 1.50 ft 4.00 ft/ft (H:V) 4.00 ft/ft (H:V) 1.00 ft 32.53 ft'/s 10.50 ft2 13.37 ft 13.00 ft 1.21 ft 0.04338 fUft 3.10 fUs 0.15 ft 1.65 ft 0.61 0.00 ft 0.00 ft 0 0.00 ft 0.00 ft Infinity ft/s Infinity ft/s 1.50 ft 1.21 ft 0.01500 fUft 0.04338 ft/ft Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.001 4/17/2009 8:06:52 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 ••••••••••••••••••••••••••••••••••••••••••• Cross Section for Trapezoidal Channel - 1 Project Description Friction Method Solve For Input Data Roughness Coefficient Channel Slope Normal Depth Left Side Slope Right Side Slope Bottom Width Discharge Cross Section Image Manning Formula Discharge 0.050 0.01500 ft/ft 1.50 ft 4.00 ft/ft (H. V) 4.00 ft/ft (Ft V) 1.00 ft 32.53 ft'/s V: 5 L. H: 1 Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 4/15/2009 10:35:17 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 1 ••••••••••••••••••••••••••••••••••••••••••• z O (7) Z Z < oo2 W 1.1. G O N1 poy a W My W N ce D O. w a W C2 W JOB NO: TSGERC/ 071217 M 03 O O Erie Substation Ex April 15, 2009 it r CO O W m w W O - CC 0 K BASIN DESIGN 1 3 T C + mQ- p. M 0 Lo 0 0 0 uo aaant Length = larger of L=4D or L=D1Q(V LaD1n(VI2 (ft) ) (ft) 0 N m 2.8 j 5.0 0 r 0 N m — M N Thicknes s,T, of riprap = 1.709350 (in) L=4D (ft) in in r Y) CO CO CO N tri N to N 'TYPE: AND SIZING CALCULATIONS. Type of dprap D50 median (from Fig. HS -20) rock size (in) m m m m J J J J C : 4. N t- 0 Q kr c6 oir aL 0.. Ntou)L0 P �inl � Irir 15" 1.25 3.7 F• 4� ide^� I..., A t{. o kHt t� ) j�y rt' N I CULVERTI CULVERT 2 CULVERT 3 POND OUTLET _Z Q J O O O O J LL W S O F z_ z_ O Q_ • m • N = rn p0 H F O "u12, z N Wcc aW Q O a z HN w J -J D O O % J J Q cc O Q C D 0 W O Z z O 0 N z w Q • m a_ cc a= Z ? CO 0 CrO W w < JZ <U ou w 00 U z_N a m O Lu W m• 3 CC Ui W H ..0 W J I 0 z • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • ERIE SUBSTATION EXPANSION ERIE, COLORADO WATER QUALITY AND DETENTION VOLUME REQUIREMENTS PROJEC- Erie Substation Expansion JOB NO: TSGERC/ 071217 CALCULATED BY: MAL DATE: April 15, 2009 JOB NO: TSGERC/ 071217 REVISED BY: DATE: 100 -YEAR DETENTION VOLUME REQUIREMENTS: Vi = Ki x A (SO -1) where: Vi - required volume where subscript is 100 -year storm (acre-feet) Ki - empirical volume coefficient where subscript is 100- or 5 -year storm A - tributary catchment area (acres) K,�o=(1.78xI-0.002xl2-3.56)/900 (SO -2) where: I - fully developed tributary catchment imperviousness (%) K100= (1.78 x 33.2 - 0.002 x 33.22 - 3.56) / 900 = 0.06 V100 = 0.06 x 7.60 = 0.46 ac -ft Required 100 -Year Detention Pond Volume = 0.46 ac -ft WATER QUALITY VOLUME REQUIREMENTS: Required Storage = [WQCV / 12] x (Area) where: Required Storage - required storage volume (acre-feet) WQCV - water quality capture volume taken from Figure SQ-2 (acre-feet) Area - The tributary catchment area upstream (acres) WQCV = a x (0.91x is -1.19 x i2+0.78 x i) where: a = 1.0 fora 40 -hour drain time and i = I / 100 WQCV = 1.0 x (0.91 x 0.332'-1.19 x 0.3322+0.78 x 0.332) = 0.16 ac -ft Required Storage = [0.16 / 12] x 7.60 = 0.10 ac -ft Required Water Quality Volume = 120% of required storage Required Water Quality Volume = 0.12 ac -ft (Figure SQ-2) According to "Weld County Storm Drainage Criteria Proposed Addendum to the Urban Storm Drainage Criteria Manual", the water quality capture volume within Weld County shall be considered a portion of the total 100 -year detention pond volume. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • PROJECT Erie Substation Expansion CALCULATED BY: MAL REVISED BY: Volume Equation. ERIE SUBSTATION EXPANSION ERIE, COLORADO PROVIDED DETENTION VOLUME Date: April 15, 2009 Date: V= 1/3 x H x (A1+A2+((A1xA2)^1/2)) JOB NO: TSGERC/07217 PROVIDED DETENTION AND WATER QUALITY VOLUMES Elevation (ft) Area (si) Volume (cf) Total Volume (cf) Total Volume (ac -ft) Remarks 5132.54 796 0 0 0.00 TOP OF MICROPOOL ELEVATION 5133 1026 418 418 0.01 5134 6124 3219 3637 0.08 5134.2 6752 1416 5053 0.12 - WATER QUALITY VOLUME 5135 11216 8543 12179 0.28 5135.7 12633 7746 19926 0.46 100 -YEAR DETENTION VOLUME 5136 13689 12432 24611 0.56 5137 16753 15195 39807 0.91 HWL 5138 20381 18537 58344 1.34 TOP OF BERM PROVIDED MICROPOOL VOLUME Elevation (ft) Area (sf) Volume (c0 Total Volume (cf) Total Volume (ac -fl) Remarks 5130.04 0 0 0 0.000 POND BOTTOM 5131 212 68 68 0.002 5132 525 357 425 0.01 5132.54 796 354 779 0.02 TOP OF MICROPOOL ELEVATION ••••••••••••••••••••••••••••••••••••••••••• PROJECT ERIE SUBSTATION EXPANSION ERIE, COLORADO WATER QUALITY OUTLET - ORIFICE DESIGN CALCULATIONS Erie Substation Expansion JOB NO: TSGERC/ 071217 CALCULATED BY: MAL REVISED BY: Date: April 15, 2009 Date: OUTLET PIPE DESIGN - CIRCULAR ORIFICE CALCULATION: Q = Co x A0 x (2 x g x HO)15 (Orifice Equation SO -15 per Urban Drainage Criteria Manual, Volume 2) where: Co= 0.60 discharge coefficient A0 = area of orifice (ft') Q = O5 RELEASE g = gravitational acceleration (32.2 ft/sec') Ho = head on orifice = HWL elevation - Bowline of orifice elevation - 1/2 of orifice diameter Try a 4.8" Diameter Orifice Opening d = 4.8"=0.40' Q=0.60x(3.1416x0.402/4)x(2x32.2x(5137.00-5132.54-0.5x0.40))05= 1.25 cfs 1.25 cfs is less than the maximum allowable release rate for the detention pond, therefore Use a 4.8" Diameter Orifice Opening PLATE DESIGN - RECTANGULAR ORIFICE CALCULATION: Q = Co x A0 x (2 x g x Ho)°.5 (Orifice Equation SO -15 per Urban Drainage Criteria Manual, Volume 2) where: Co = 0.60 discharge coefficient A0 = area of orifice (ft') Q = O5 RELEASE g = gravitational acceleration (32.2 ft/sec') Ho = head on orifice = elevation at top of inlet box - water quality elevation - 1/2 of orifice height Try an orifice opening of 1.0' H x 0.5' L Q= 0.60 x 0.5 x (2 x 32.2 x (5135.75-5134.2-0.5x1.0))05= 2.47 cfs The rectangular orifice allows 2.47 cfs into the outlet box, which is greater than the O5 RELEASE of 1.29 cfs, therefore Use an Orifice Opening of 1.0' H x 0.5' L ••••••••••••••••••••••••••••••••••••••••••• PROJECT ERIE SUBSTATION EXPANSION ERIE, COLORADO WATER QUALITY OUTLET - RELEASE RATES Erie Substation Expansion JOB NO: TSGERC/ 071217 CALCULATED BY: MAL REVISED BY: Date: April 15, 2009 Date: Weld County policy is to release detained water at the rate of the runoff of the 5 -year storm falling on the undeveloped site per Section 8-11-30.17 of the Weld County Storm Drainage Criteria Addendum to the Urban Storm Drainage Criteria Manuals. Q5 RELEASE = 3.36 cfs Maximum Allowable Release Rate For A 5-YR Detention Pond: O5 RELEASE = C5 X A where C5 = 5 -year Release Rate Multiplier and A = Tributary Area to Pond in Acres C5 = 0.17 cfs/acre (for Soil Group C per Urban Drainage Criteria Manual, Volume 2. Table SO -1) O5 RELEASE = 0.17 cfs/acre x 7.60 acres QS RELEASE 1.29 cfs The maximum allowable release rate based on soils type is less than the calculated 5 -year flow rate on the undeveloped site, therefore the smaller flow will be used for the detention pond release rate. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 1 of 3 Designer: Mikhail Litvak Company: Manhard Consulting, Ltd. Date: April 15, 2009 Project: Erie Substation Expansion Location: Weld County, Colorado 1. Basin Storage Volume A) Tributary Area's Imperviousness Ratio Ii = I,/ 100 ) B) Contributing Watershed Area (Area) C) Water Quality Capture Volume (WQCV) (WQCV=1.0' (0.91' I'- 1.19' I' + 0.76' h) D) Design Volume: Vol = (WQCV / 12)' Area' 1.2 I, = 33.20 i = 0.33 Area = 7.600 acres WQCV = 0.16 watershed inches Vol = 0.1224 acre-feet 2. Outlet Works A) Outlet Type (Check One) X Orifice Plate Perforated Riser Pipe Other: B) Depth at Outlet Above Lowest Perforation (H) H = 1.66 feet C) Recommended Maximum Outlet Area per Row, (A") Ap = 0.4 square inches D) Perforation Dimensions: i) Circular Perforation Diameter or D = 0.750 inches ii) Width of 2" High Rectangular Perforations W = inches E) Number of Columns (nc, See Table 6a-1 For Maximum) nc = 1 number F) Actual Design Outlet Area per Row (A0) A. = 0.4 square inches G) Number of Rows (nr) nr = 5 number H) Total Outlet Area (A0,) Ao, = 2.2 square inches 3. Trash Rack A) Needed Open Area: Ai = 0.5' (Figure 7 Value)' Ap, B) Type of Outlet Opening (Check One) A, = 77 square inches X ≤ 2" Diameter Round 2" High Rectangular Other: C) For 2", or Smaller, Round Opening (Ref.: Figure 6a): i) Width of Trash Rack and Concrete Opening (W,,,,,„) from Table 6a-1 W„., = 3 inches ii) Height of Trash Rack Screen (Hrn) Hrn = 50 inches EDB Orifice Sizing Calculations (041509).xls, EDB 4/17/2009, 9:45 AM • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 2 of 3 Designer: Mikhail Litvak Company: Manhard Consulting, Ltd. Date: April 15, 2009 Project: Erie Substation Expansion Location: Weld County, Colorado iii) Type of Screen (Based on Depth H), Describe if "Other" iv) Screen Opening Slot Dimension, Describe if "Other" v) Spacing of Support Rod (0.0.) Type and Size of Support Rod (Ref.: Table 6a-2) vi) Type and Size of Holding Frame (Ref.. Table 6a-2) D) For 2" High Rectangular Opening (Refer to Figure 6b): X S.S. #93 VEE Wire (US Filter) Other: X 0.139" (US Filter) Other: 0.75 inches #156 VEE 3/8 in. x 1.0 In. flat bar W = inches I) Width of Rectangular Opening (W) ii) Width of Perforated Plate Opening (Wcppc = W - 12") iii) Width of Trashrack Opening (W0 ,,m) from Table 6b-1 iv) Height of Trash Rack Screen (Hie) v) Type of Screen (based on depth H) (Describe if "Other") vi) Cross -bar Spacing (Based on Table 6b-1, Klempi" KPP Grating). Describe if "Other" vii) Minimum Bearing Bar Size (Klemm' Series, Table 6b-2) (Based on depth of WOCV surcharge) W<0„, = inches Wopen„p = inches HTR = inches KlempTM KPP Series Aluminum Other: inches Other: 4. Detention Basin length to width ratio 1.50 (LNV) Rteti rebay Basin - Enter design values (3% to 5% of to 5 of Des0.1acre-feet 5% of Design Volue (0.0037-0.0061actor Pipe Diameter ain This volume-esunderinletcontrd Bottom and Sides :o:a.BottomandSi;:esu:ri;tcontr yes/no EDB Orifice Sizing Calculations (041509).xls, EDB 4/17/2009, 9:45 AM • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Design Procedure Form: Extended Detention Basin (EDB) - Sedimentation Facility Sheet 3 of 3 Designer: Mikhail Litvak Company: Manhard Consulting, Ltd. Date: April 15, 2009 Project: Erie Substation Expansion Location: Weld County, Colorado 6. Two -Stage n - See Figure EDB-1 A) Top Stage (Depth Dko = um) Top Stage Storage: no less than 9 . f Design Volume (0.1218 acre-feet.) B) Bottom Stage Depth (Des = 0.33' Minimum Below Trio annel Invert) Bottom Stage Storage: no less than 0.5% of Design Volume 6 e ) Storage = A' Depth Above WS To Bottom Of Top Stage C) Micro Pool (Minimum Depth = the Larger 0.50 ' Top Stage Depth or 2.5 Fe D) Total e: Volvo, = Storage from 5A + 6A + 66 ust be > Design Volume in 1D, or 0.1224 acre-feet.) Dvv0 = e Storage= acre-feet Des = feet Storage= acre-feet Surf. Area= acres Depth= 2.50 feet Volvo, = acre-fe 7. Basin Side Slopes (Z, horizontal distance per unit vertical) Minimum Z = 4, Flatter Preferred Z = 4.00 (horizontal/vertical) 8. Dam Embankment Side Slopes (Z, horizontal distance) per unit vertical) Minimum Z = 3, Flatter Preferred Z = (horizontal/vertical) 9. Vegetation (Check the method or describe "Other") X Native Grass Irrigated Turf Grass Other: Notes: • EDB Orifice Sizing Calculations (041509).xls, EDB 4/17/2009, 9:45 AM ••••••••••••••••••••••••••••••••••••••••••• 15" Detention Pond Outlet Pipe - Capacity Calculation Project Description Friction Method Solve For Input Data Roughness Coefficient Channel Slope Normal Depth Diameter Results Discharge Flow Area Wetted Perimeter Top Width Critical Depth Percent Full Critical Slope Velocity Velocity Head Specific Energy Froude Number Maximum Discharge Discharge Full Slope Full Flow Type GVF Input Data Downstream Depth Length Number Of Steps GVF Output Data Upstream Depth Profile Description Profile Headloss Average End Depth Over Rise Normal Depth Over Rise Downstream Velocity Upstream Velocity Manning Formula Discharge SubCritical 0.013 0.00500 ft/ft 1.25 ft 1.25 ft 4.57 ft'/s4-- 4.57ccs < A'le%.f4bit_ 23 ft' 0.Ata.Jl cC-Ca 0*Ata%:.e\ 3.93 ft 0.00 ft 0'A J. 0.87 ft 100.0 0/0 0.00732 ft/ft 3.72 ft/s 0.22 ft 1.47 ft 0.00 4.91 ft'/s 4.57 n'/s 0.00500 ft/ft 0.00 ft 0.00 ft 0 0.00 ft 0.00 ft 0.00 % 100.00 % Infinity Ws Infinity ft/s Bentley Systems, Inc. Haestad Methods Solution Center Bentley FlowMaster [08.01.071.00] 4/17/2009 9:46:56 AM 27 Siemons Company Drive Suite 200 W Watertown, CT 06795 USA +1-203-755-1666 Page 1 of 2 ••••••••••••••••••••••••••••••••••••••••••• PROJECT ERIE SUBSTATION EXPANSION ERIE, COLORADO ORIFICE DESIGN AND EMERGENCY SPILLWAY CALCULATIONS Erie Substation Expansion JOB NO: TSGERC/ 071217 CALCULATED BY: MAL REVISED BY: Date: April 15, 2009 Date: EMERGENCY SPILLWAY DESIGN - WEIR CALCULATION: Q = Cecw X L x H31' (Weir Equation SO -18 per Urban Drainage Criteria Manual, Volume 2) where: C = broad -crested weir coefficient (A value 3.0 is often used in practice) L = horizontal length of weir Q = Qtoo into pond H = head above weir crest 25.6 cfs = 3.0 x L x (0.5)12 L = 24.1 feet minimum Hello