Loading...
HomeMy WebLinkAboutDrainage Reports - 06/30/1999 (2)Final Drainage Report for Landings Bay (Formerly Courtyard Commons) Fort Collins, Colorado May 17, 1999 � 1 � � 1 r 1• ENGINEERING Final Drainage Report for Landings Bay (Formerly Courtyard Commons) Fort Collins, Colorado May 17, 1999 Prepared For: Lagunitas Companies 3307 South College Ave Suite 200 Fort Collins, Colorado 80525 Prepared By: Northern Engineering Services, Inc. 420 South Howes, Suite 202 Fort Collins, Colorado 80521 (970)221-4158 Fax(970)221-4159 Project Number: 9837.00 51h Submittal May 17, 1999 Mr. Glen Schlueter City of Fort Collins Stormwater Utility t700 Wood Street Fort Collins, Colorado 80522 RE: Landings Bay Fort Collins, Colorado Project Number: 9837.00 Dear Glen: , I Northern Engineering is quite pleased to submit this revised Final Drainage Report for Landings Bay (formerly known as Courtyard Commons) for your review for the last time. It represents a study of existing and proposed stormwater characteristics tof the project site. This report was prepared in compliance with technical criteria set forth in the, City of Fort Collins, Storm Drainage Design Criteria and Construction Standards manual. If you should have any questions or comments as you review this report, please feel free to contact me at your convenience. Sincerely, NORTHERN ENGINEERING SERVICES, INC. \\\\\\1UII11111111//////j ' Roger As, P.E. ��P�o�oEA% c°SlF O o O �O�tiR G,pNNQ i cc: Jon Prouty - 27362 s 0 `///z J 6'10IIII II1\\\\������\ 420 SOUTH HOWES, SUITE 202, FORT COLLINS, COLORADO 80521, (970) 221-4158, FAX (970) 221-4159 I C i 1 1 1 i I Final Drainage Report for Landings Bay I. GENERAL LOCATION AND SITE DESCRIPTION Landings Bay (Formerly known as Courtyard Commons) project is located North of the Landings project, North of Boardwalk Drive, East of JFK Parkway, and west of Landings Drive. The site is also bounded on the north by the Larimer Canal No. 2. The site can also be described as a portion of Section 36, Township 7 North, Range 69 West of the 6th PM, City of Fort Collins, Larimer County, Colorado. A vicinity map of the site is included in the appendix of this report. This site is also located within the Foothills Major Drainage Basin, as defined by the City of Fort Collins Stoimwater Utility. This site includes approximately 6.32 acres, including the adjacent roadways. The site is presently undeveloped, and consist mainly of native grasses. As mentioned above, the Landings Office Park is currently being constructed on the south side of this site. The site generally slopes from the south to the north at slopes less than 4%. There is also an existing detention pond located on the site which was constructed with the Shopko project. This pond is referred to in the Parsons study as Pond B. Plans for this site include multi -family residential buildings, with associated parking and garages, and 5 additional office buildings, similar to the product currently being constructed in the Landings. H. HISTORIC DRAINAGE As mentioned above, the site is presently undeveloped, and consists mainly of native grasses and vegetation. JFK Parkway has been fully developed on the west side of the site, and will be widened with this project. Landings Drive has also been fully developed, and will remain essentially in tact as a result of this project. The Landings is currently being constructed on the south side of this project. Currently, runoff is conveyed to the existing Larimer Canal No. 2, and to the existing pond constructed with Shopko. Runoff from Landings Drive, to the approximate new driveway to Courtyard Commons is intercepted by an existing curb inlet, and routed through the High Pointe detention pond to Larimer Canal No. 2. The remainder of Landings Drive, approximated by LD2 continues to flow north across the Larimer No. 2 to the north. Flows from JFK Parkway flows to the north to an existing curb inlet at the Larimer No. 2, through the existing pond, and to the Larimer No. 2. I I I I I I I I I M. DEVELOPED DRAINAGE Design Criteria and References Drainage criteria outlined in both the City of Fort Collins Storm Drainage Design Criteria Manual. and Storm Drainage Criteria Manual by the Urban Drainage and Flood Control District have been used for this Drainage Study. Hydrologic Criteria The Rational Method was used to estimate peak stormwater runoff from the proposed site. The 10 year storm event and the 100 year storm event was used to evaluate the proposed drainage system. Rainfall intensity data for the Rational method was taken from the City of Fort Collins Stormwater Utility Intensity curves (Figure 3-1). Hydraulic Criteria City of Fort Collins Storm Drainage Criteria has been used for all hydraulic calculations. In addition, the detention volumes required for this development have been verified using the FAA method for detention ponds developed by the UDFCD was used. Drainage Concepts The site has been broken down into 8 smaller subbasins onsite, as well as 5 subbasins adjacent to the site. Basin C-1 is the majority of the office park. Developed runoff will be conveyed towards the center of the basin, and collected in a Type C area inlet, and ultimately piped to the existing detention pond. Developed runoff from Basin C-2 will be conveyed towards the center of the site via curb and gutter, to a proposed Type C area inlet, and will be piped to the existing detention pond. Developed runoff from basins C-3, 4, and 5 will also be conveyed towards the center of the site via curb and gutter, and will be intercepted by a proposed 12.5' Type R curb inlet, and also piped to the existing detention pond. Per discussions with Stormwater, Basin C-6 will be allowed to sheet flow directly to Larimer Canal No. 2. The peak flows from this basin, leaving the site undetained, will be deducted from the allowable release from the site detention facility. Basin C-7 represents the northerly half of the roof from building G. The developer will connect the roof drains to the site storm sewer system and direct these flows to the site detention pond. I L i I I "I .1 I 11 :1 L -1 11 Basin C-8 represents the basin which includes the existing pond, and will be directed to this pond by surface flows. Subbasin LC-1 represents that portion of the site, which is adjacent to and includes the Larimer No. 2. This area will not be disturbed, and will be allowed to continue to sheet flow to the canal. Peak runoff for the 100 year event was calculated to be approximately 3.3 cfs. These flows were subtracted from the allowable release rate for the site identified by the JFK Parkway drainage study by Parsons & Associates, approved by the City. Subbasins D2 and D3 correspond to the subbasins identified in the Landings drainage study by Northern Engineering. Developed runoff from Subbasin D2 (Landings Drive), including portions of the Landings project, will be conveyed to the north via curb and gutter to an existing inlet located at the proposed driveway section for Courtyard Commons. This is currently a Type R inlet, which will be reconstructed as an area inlet. This modified inlet will still intercept these flows, convey them through the High Pointe detention facility, and ultimately to the Larimer No. 2. Developed flows from subbasin D3 (JFK Parkway) are conveyed to the south via curb and gutter to an existing 15' curb inlet located at the corner of JFK and Boardwalk. This project does not significantly increase the flows to this inlet. A subbasin has been identified on our plan as subbasin LD2, which represents that portion of Landings Drive, currently existing, which is not intercepted by the curb inlet, and which currently is conveyed to the north via curb and gutter. This project does not significantly affect the performance or nature of these flows. Basins JFK 1 and 2 represent existing JFK Parkway, and approximates basins A, E, and F identified in the Parsons study for JFK Parkway. Developed flows currently are directed to existing curb inlets located on the uphill side of the existing box culvert at the Larimer Canal No. 2. Flows from these inlets are directed into the existing detention pond. The existing pond, referred to in the Parsons study as pond B, has been certified as a part of the Shopko project, and volume has again been checked as a part of this study. The allowable release rate from the pond was identified to be 12.54 cfs. There is an existing 24" outlet pipe from the pond. This will be modified to include an orifice plate which will be sized to release approximately 2.07 cfs from the pond. The Shopko project will be allowed to bypass approximately 5.02 cfs through the pond. The orifice opening will not be sized to accommodate this 5.02 cfs bypass, however the overflow weir has been. This will reduce the outflow from the pond in minor storm events. Subbasins C6 and LC1 are free releasing into the canal. This results in an allowable release from our site of 2.07 cfs, which was the basis of our volume verification. The 100 year WSEL was determined to be approximately 30.57. The pond would currently overflow at approximate elevation 30.85. Detention storage provided to elevation 30.57 was calculated to be approximately 1.217 acre feet. An emergency overflow weir will be constructed as a part of this project, to direct emergency spills to the Larimer No. 2. Since construction, the existing pond has been revegetated and will provide a significant water quality component to this project, as well as the other developed flows entering the pond. It is therefore our opinion, that this pond should not be disturbed for the addition of temp siltation pond. 11 I 1 r I General Concept Courtyard Commons lies within the Moderate Rainfall Erodibility Zone, and the Moderate Wind Erodibility Zone, per the City of Fort Collins zone maps. The desired effectiveness goal for this site was estimated to be approximately 85% The intent of the erosion control plan for the site include the following guidelines. As these measures can vary depending on the time of year construction activities take place, as well as the construction window involved, we would look to the contractor to work closely with the City to insure the intent of the plan is generally complied with. It is the intent of the owner to move quickly ahead with development once overlot grading takes place. It is anticipated that overlot grading would start sometime around January, 1999, or sooner if possible. Therefore, once overlot grading and utilities have been completed, the owner would like to restabilize all disturbed areas, either with vegetative means, or by hard surfaces. In no cases shall restabilization occur more than 30 days after disturbance. In addition, silt fence will be provided around most of the exterior of the disturbed areas; gravel inlet filters will be installed at all curb inlets, curb openings, and pipe entrances. Straw bale check dams will be placed in all open channels, at a minimum of 250' intervals. Temporary vehicle wash pads will be located at the anticipated construction traffic entrances to the site. All construction activities must also comply with the State of Colorado permitting process for Stormwater Discharges associated with construction activities. A Colorado Department of Health NPDES discharge permit will be required before any construction grading can begin. V. CONCLUSIONS Compliance with Standards All computations within this report have been completed in compliance with the City of Fort Collins Storm Drainage Design Criteria. Drainage Concept The proposed drainage concepts presented in this study and shown on the grading and drainage plans adequately provide for the conveyance and detention of developed runoff from the proposed development. If groundwater is encountered during construction, and dewatering is used to install utilities, a State of Colorado Construction Dewatering Wastewater Discharge Permit will be required. 1 I d I Stormwater Quality Because water quality is important to this developer, water quality mechanism will be incorporated into all aspects of final design of drainage systems. Erosion Control Concepts Per the City of Fort Collins Erosion Control Reference Manual for Construction Sites, at the time of Final Design, the erosion control performance standard will need to be calculated and appropriate measures taken to control rain and wind erosion from the site REFERENCES 1. Storm Drainage Design Criteria and Construction Standards. City of Fort Collins, Colorado, May, 1984. 2. Drainage Criteria Manual. Urban Drainage and Flood Control District, Wright -McLaughlin Engineers, Denver, Colorado, March, 1969. 3. Final Drainage and Erosion Control Study for JFK Parkway, by Parsons & Associates, dated May 19, 1992 4. Final Drainage and Erosion Control Study for Shopko. by TST 5. Final Drainage and Erosion Control Study for the Landings. by Northern Engineering Services I] 11 1 I LJ I 1 t RESPONSE TO CITY COMMENTS 11 1 1 1 May 17, 1999 1 Mr. Basil Hamdan Water/Wastewater - Stormwater Division 700 Wood Street 1 Fort Collins, CO 80522-0580 RE: Landings Bay (formerly Courtyard Commons PUD) Response to City Comments Basil, 1 The following letter, included in the Final Drainage Study, is in response to your project comments, dated May 11, 1999 1 1. The ROW shown is the future Right -of -Way, and in fact is being dedicated with this project, so it will be the existing Right -of -Way. I have attached a grading schematic for the pond based on the sidewalk being relocated. The volume of the pond is reduced along the frontage of the site, but can be compensated for by regrading the area in the comer of the site. 2. These trees have been schematically indicated. Should the contractor need to relocate these due to construction, he has been instructed to replace them onsite 3. This has been included, as Section A -A on the Drainage plan. 1 4. OK ' S. Jon Prouty will provide these to the City Please call if you have any additional questions regarding this resubmittal. I am available to meet with you 1 to discuss any of the revisions, or the study. Sincerely, 1 ' Roger A Curtiss, P.E. Project Engineer ' cc: Jon Prouty 1 PROJECT COMMENT SHEET City of Fort Collins Current Plannine DATE: April 30, 1999 TO: Stormwater PROJECT: #38-98A Landings Bay — PDP — Final Compliance (LUC) :54'c,le o 1+ All comments must be received by l�"-Flu'�chs no later than the staff review meeting: Wednesday, May 12, 1999 1. There seemed to be some misunderstanding regarding the previous comment about accounting for the future widening of JFK Parkway. Please show the future R.O.W. of JFK Parkway on the plans. If the future R.O.W. impacts the current grading of the pond, please show the new grading of the pond to insure that there is adequate capacity. RESPONSE: 2. Please update the existing conditions plan as it does not show the existing small trees in the pond which were confirmed during a site visit. Will these trees be impacted with the proposed outfall into the pond? RESPONSE: (continued on back) Date:. (5 �I f/1� Signature: CHECK HERE IF YOU WITH TO RECEIVE COPIES OF REVISIONS 04r� VUCAIU°- ' X Plat YSite &Drainage Report �LOtherr wscs P°`AW^ Gvt IN ,Utility Redline Utility YLandscape City of Fort Collins 3. Please provide a cross-section where indicated on the drainage plan and show the water surface elevation for the overflow condition. RESPONSE: 4. There are a few other typos on the plans. Please correct these as needed. RESPONSE: 5. Just a reminder that offsite grading easements and ditch approval needs to be obtained prior to mylars being submitted. RESPONSE: Please refer to the redlined plans and report for additional review comments LandingsBay-4.doc I I ' April 15, 1998 Mr. Basil Hamdan Water/Wastewater - Stormwater Division 700 Wood Street Fort Collins, CO 80522-0580 RE: Landings Bay (formerly Courtyard Commons PUD) Response to City Comments Basil, The following letter, included in the Final Drainage Study, is in response to your project comments, dated February 25, 1999 Offsite easements will be provided prior to mylats being submitted for signatures. This includes the Shemardian property. 2. Ditch Company signatures will also be obtained prior to mylars being routed to the City for signatures. 3. OK, the overflow was recalculated to include Basin C-2 4. Revised 5. Calculations show that approximately 1,188 cf of additional storage would be needed, and the area north of the existing pond would be able to provide this increased volume. 6. Per a meeting with Basil, it was agreed that we would specify an erosion control fabric be used in lieu of riprap. 7. OK 8. Our new layouts have been provided to V*F Ripley 9. Done Please call if you have any additional questions regarding this resubmittal. I am available to meet with you to discuss any of the revisions, or the study. Sincerely, Roger A Curtiss, P.E. Project Engineer REVISION COMMENT SHEET DATE: February 4, 1999 TO: Stormwater PROJECT: #38-98 Landings Bay — PDP — Type II (LUC) All comments must be received by Steve Olt no later than the staff review meeting: Wednesday, February 24, 1999 No Comment 9 Problems or Concerns (see below or attached) 1. Any offsite grading that is occurring on other properties needs an offsite grading easement (possibly on southwest portion of site?). RESPONSE: 2. Approval from the ditch company is still required for the release from basin C6 into the Latimer No. 2. RESPONSE: 11 11 (continued on back) =No =uigg ' Q11BCB HERB IF YOU RM W RBCm COPO OF REVISIONS .� P4 She Dwim � — g p�ya - A_ - 1.b- � S Carprr•eS I 3. The overflow calculation for Basins C-3,4,5 to C-8 should include the overflow discharge from basin C-2 since the overflow from C-2 flows into basin C-5. In addition, please determine the WSEL for this overflow immediately adjacent to the Larimer No. 2. The total overflow for Basins C-2,3,4,5 should not spill into the ditch ' and there should be a 1' freeboard between the HWL and minimum opening elevation (M.O.E.) of the adjacent buildings. Please show a cross-section on the plans where specified with the WSEL & building M.O.E. indicated. RESPONSE: 4. For the UDSEWER analysis of the,storm sewer, the design flow at manhole #9 should be 34.7. In addition, the pipe size for sewer nos. 910, 1011, and 1112 should ' be 24". Please make these corrections in the analysis as well as on the storm sewer profile. RESPONSE: ' 5. In the pond sizing computation, the future widening of JFK Parkway needs to be accounted for. Please compute the pond volume for the future condition. If there is ' insufficient volume provided, the pond could be enlarged to the north to compensate for the loss of volume. ' RESPONSE: ' 6. Please note on the plans that the riprap from the storm sewer outfall and on the emergency overflow weir both need to be buried and revegetated. RESPONSE: ' 7. Please specify the minimum opening elevation (M.O.E.) for buildings E, F, G, H. There needs to be 1' of freeboard between the pond/swale HWL and the elevation at which any stormwater would enter the buildings. ' RESPONSE: ' 8. Please revise the site and landscape plan to reflect the current storm sewer layout. ' RESPONSE: I ' landingsbay-3.doc IJ 9. For the concrete encasement of the storm sewer, please specify the length of encasing. RESPONSE: i Please refer to the redlined report and plans for additional review comments. u N I I I 1 ' landingsbay-3.doc I February 3, 1998 Mr. Basil Hamdan Water/Wastewater - Stormwater Division 700 Wood Street Fort Collins, CO 80522-0580 RE: Landings Bay (formerly Courtyard Commons PUD) r. Response to City Comments Basil, The following letter, included in the Final Drainage Study, is in response to your project comments, dated December 30, 1998, to Steve Olt. i, r 1. Storm sewer line 34 has been eliminated from this design. The bend loss in pipe section 12 has been revised to reflect 1.00 as a loss coefficient. Since pipe section 34 was eliminated, pipe 38 does not have a lateral. 2. Per discussions with Mark McCallum & King Surveyors, the existing easements are not our clients to vacate. Mark said to leave them as they are. 3. Per discussions between Jon Prouty and Basil Hamdan, Basin C-6 will be allowed to sheet flow directly to Larimer Canal No.2. Therefore, this overflow swale has been eliminated. 4. Riprap at the outlet of Pipe section 12 was revised to be 18" of Type L. 5. This has been revised 6. OK 7. OK. A note regarding compaction has been added to the plan. Please call if you have any additional questions regarding this resubmittal. I am available to meet with you to discuss any of the revisions, or the study. i Sincerely, Roger A Curtiss, P.E. Project Engineer cc: Jon Prouty ,1 I PROJECT: #38-98 Courtyard Commons - Type II (LUC) - PDP All comments must be received by Steve Olt no later than the staff review meeting: Wednesday, December 30, 1998 ❑ No Comment Problems or Concerns (see below or attached) 1. In the UDSEWER storm sewer analysis, the invert elevations for sewer ID #34 does not match what is shown on the profile. Please clarify. Also, the bend loss coefficient for sewer ID #12 should be 1.00 because the outlet is submerged, and there should be some lateral loss coefficient for sewer ID #38. Please revise UDSEWER as necessary. RESPONSE: t, t ` 2. Since the site is being newly platted, please r1vacate all old easements 'and then Nl� rededicate with this plat. RESPONSE: Date: 11 (continued on back) F '1 No C►II... CHECK HERE F YOU WISH u+.. TO RECEIVE COPIES OF REVISIONS � SeJL�"" �k w � zRx UsY � WapscyFo I rz I i 3. The Flowmaster analysis of the overflow from basin C6 to basin C7 assumes an incorrect Mannings Coefficient. According to Table 74 of the City of Fort Collins SDDC manual, for flow depths < 2.0 R, n = 0.060. Please revise analysis and make sure no excess flows will overtop into the Larimer #2. RESPONSE: 4: When determining the size of riprap to use, it is assumed that Type L riprap is equivalent to Class 6 riprap. Please clarify where this is stated. According to Table 5-1 in the UDFCD, Type L riprap has a d50 of 9". RESPONSE: 5. The proposed contours at the south site boundary do not seem to tie into existing contours. Please show more clearly how these contours tie-in. RESPONSE: 6. Please provide an analysis of the emergency overflow condition in the case where all Nthe inlets where plugged — i.e. where would flows be routed, where ponding would occur, etc. Please make sure that none of the buildings would be flooded in this case. RESPONSE: 7. Since the storm sewer adjacent to the Larimer No. 2 is very close to the banks of the canal, it is a concern of ours that the fill of the storm sewer could be washed out I" during high flow events. Please make sure that this will not occur by ensuring compaction will take place during the trenching of the storm sewer. RESPONSE: 1� Erosion/Sediment Control Comments 1. All previous comments have been addressed, the plan is OK as submitted. Thanks. 1 Please refer to the redlined report and plans for additional review comments. CtyardCom-2.doc A-7 tj SERVICES 1NC` December 9, 1998 Mr. Basil Hamdan Water/Wastewater - Stormwater Division 700 Wood Street Fort Collins, CO 80522-0580 RE: Courtyard Commons PUD Response to City Comments Basil, The following letter, included in the Final Drainage Study, is in response to your project comments, dated September 11, 1998, to Steve Olt. These flows have been rerouted through the site to the existing detention pond. 2. This has been graded such that it will act as an overflow swale and direct flows to the existing detention pond. Calculations have been included in the report. 3. Ditch Company signature blocks were originally shown on the Utility plans. We have contacted a Ditch Company representative and have discussed this project with them, including the grading adjacent to their ditch. 4. OK 5. Flow arrows have been added 6. This has been profiled 7. These are included in the appendix of the report 8. We have attempted to minimize the number of conflicts with proposed contours. The grading plan also has these contours in tact, and should be used as a basis for the site grading. 9. This is included on the detail sheet 420 SOUTH HOWES, SUITE 202, FORT COLLINS, COLORADO 80521, (970) 221-4158, FAX (970) 221-4159 I 11 Erosion/Sediment Control Comments 1. These were included on the grading plan. They have been duplicated on the Drainage and Erosion Control sheet. 2. A note has been included on the cover sheet 3. Riprap has been included as the outlet of the only proposed storm sewer entering the existing pond 4. The pond is existing 5. A note was included on the original submittal, and is still included. A note will also be added regarding construction traffic, although at this point we do not have direction as to where construction traffic will enter the site. 6. They were included in the appendix in the original submittal, and have been included again. r7. This is included with this submittal Please call if you have any additional questions regarding this resubmittal. I am available to meet with you to discuss any of the revisions, or the study. Sincerely, oqr.� Roger A Curtiss, P.E. Project Engineer cc: Jon Prouty I 1 v PROJECT COMMENT SHEET City of Fort Collins Current Planning DATE: August 13, 1998 TO: Stormwater PROJECT: #38-98 Courtyard Commons - PDP Type II All comments must be received by Steve Olt no later than. the- staff review meeting: Wednesday, September 9,1998 1. It is unacceptable to use J.F.K. Parkway to route onsite runoff. Please make changes as needed (add storm sewers/inlets/etc) to keep runoff onsite and route to detention pond. RESPONSE: 2. For the length of property that runs adjacent to the Larimer Canal #2, please grade it as an overflow swale (i.e. flows not captured by the area inlets should not be going into the ditch), provide cross -sections of overflow swale & 100-year.HWEL when inlets are 100% clogged. RESPONSE: (continued on back) if , (m lM IF YOU W1SA TO RM 00M OF RMIONS Fly -C Ski XDlaioage R" 1* X> e cc 5'1 o it City of Fort Collins i 3. In addition, please obtain ditch company approval/signature as work will be done very close to the ditch and indicate where the ditch maintenance accessway is located. RESPONSE: 4.. For all riprap protection shown on the plans, please indicate sizes/types and provide supporting calculations in the report. RESPONSE: 5. Flow arrows are missing from the drainage plan. Please include flow arrows to show direction of flow. RESPONSE: 6. The section of pipe which includes inlets 9 and 10 (up to 4' manhole) is not shown in profile view nor does it have supporting calculations. Please provide profile view of this pipe and include supporting calculations (for pipe and inlets) in the report. RESPONSE: 7. Please provide street capacity calculations to show that flows on-J.F.K. Parkway and Landings Drive fall within minor/major storm criteria. RESPONSE: 8. Many of the labels for various inlets interfere with proposed contours. Please revise plans so the inlet labels point out inlets distinctly and contour numbers can be read. RESPONSE: 9. Please show cross-section of emergency overflow'weir on plans with spot elevations and weir dimensions indicated. RESPONSE: yctyardcom l .doc Erosion/Sediment Control Comments 1. The plan needs standard erosion control notes. 2. The plan needs BMP details or a note indicating where in the plan set they can be found. 3. There should be a pond outlet gravel filter instead of the straw bales shown. 4. There should be a note on the plan indicating that the detention area is to be excavated as the first step in overlot grading. 5. The silt fence needs to be shown in clearer detail on the drawing (or a note added stating that it goes around the entire site, east north and west). Please take into consideration the fact that construction vehicles need to enter and exit the site, indicate where this is to occur. 6. There are no EFF calculations in the report. 7. There is no erosion control escrow calculation in the report. Please refer to the redlined report and plans for additional review comments. ctyardcoml .doc I APPENDIX I I I 17 11 S. 11 '1 I i I zgVICINITY MAP 1 "=2000' I DRAINAGE STUDY, PARSONS & ASSOCIATES I I I i 1 i 1 �v b/`o Final roved Report FINAL DRAINAGE & EROSION CONTROL REPORT FOR JFK PARKWAY (BOCKMAN DRIVE TO LARIMER #2 CANAL) FORT COLLINS, COLORADO SEPTEMBER 19, 1991 (REVISED MAY 19, 1992) PREPARED FOR: WAYNE K. SCHRADER PREPARED BY: PARSONS & ASSOCIATES CONSULTING ENGINEERS 432 LINK LANE PLAZA FORT COLLINS, COLORADO 80524 (303) 221-2400 PROJECT NUMBER: 91.13 JFK FINAL DRAINAGE & EROSION CONTROL REPORT FOR JFK PARKWAY (BOCKMAN DRIVE TO LARIMER It 2 CANAL) IINTRODUCTION This drainage investigation has been prepared along with final plans for the ' construction of a 400' section of the JFK Parkway from Bockman Drive north to the Larimer L#2 Canal. This study was prepared in conformance with the City of Fort Collins "Storm Drainage Design Criteria and Construction Standards." 1 SITE DESCRIPTION The JFK Parkway is an arterial roadway which will eventually run from the Foothills Fashion Mall south to Harmony Road, roughly parallel to and east of South College Avenue. A section of this roadway between Horsetooth Road and Boardwalk Drive has not been completed. This project will complete a 400't portion of JFK Parkway approximately !� midway between Boardwalk Drive and Horsetooth Road immediately adjacent to the Toys "R" IUs site. This construction is being completed by the adjacent property owners to fulfill i I 1 1 I I requirements set by the City of Fort Collins as part of the Toys "R" Us/Western Auto P.U.D. approval. The proposed JFK Parkway will be a seventy (70) feet wide street section in a one - hundred (100) foot right-of-way. A preliminary grade was established for the JFK Parkway between Boardwalk Drive and Horsetooth Road as part of the Toys "R" Us/Western Auto P.U.D. construction plans. This vertical grade increases from Boardwalk to the north at a rate of 2.0% which results in a six foot deep cut in the ridge line approximately 300' north of Boardwalk Drive. From here the roadway grades change to a 3% downward slope. This grade was controlled by the elevation of the Larimer #2 Canal and the existing improvements of the JFK Parkway at Horsetooth Road. HISTORIC DRAINAGE The JFK Parkway right-of-way, the property adjacent to the Parkway, and the south one-half of Bockman Drive all historically drained towards the Larimer #2 Canal. These areas are further outlined in Figure 1 as Basins A-J. Flows from these areas were typically undetained sheet flows that accessed the Larimer #2 Canal through numerous low spots in the canals south bank. &Z S7'R ACHAN CION ENTL. o ;yE •: S l.i 960.0 19].Y es.� P SUED I `J ! SI ON o MD P 15.0 v n ® y 00 O N y Q r 9 • V �. 3c F_ENEY S 8 IVISION Y .B I.B.O • i•. -� vi C ® V® A�•• ' 1<IP a51 0 EVE m o . .. 05� �m m GAD Ie6.B „1.1.0 r 16T.1 ® 0 0 e• ° `T ,� 301 .0 r P O Q Z Ye.l R Z n a a)° ® m ®im N Y Q Ya.il a• '�' 09 EF OATORY HEIGHTS y �w a o a (MDT, MD T( 301 0 212.10 N 2 ..y2 0© P 1 0 es.a 1 I AN11 '. z 300 P TOYS 'R' US / 0 0® m WESTERN AUTO M.U.D. EXIST. 6 p e 500 "'°' • > 54 RCP II� p ° n n �I ^ V qY q5 :VPP L q O } ® II ti 17,• QP•• 02 Daps C 55.7 I . r`/ I O 120 10 Oi ® 0. M 16 W AUTO N = f TOYS IRI US '�� al z o s�vP® CS W .o. P IT_WP K 56.2p 16].B2 Y61. 7 I Q � � a 62•i 5 I MD BASIN C B0CKMAN OR VE— 0.4 �� ty s ®� : - a. 3 p® _. � _ _ _ — _ 1gP ' °a •ui% Z Ili n * I ue.. ®TEMPORARY �O o it 09SER TORDETENTION ME IGMT Y _ / I '� .r 5.02 efs'a /} TEMPORA®RY t^ ss v DETENTION O RELEASE I 9� ;y' -i ul.an BASIN D (S.IODc)IF m a* 11 4-0.46 ].o 0 .o , 13 I co BASIN J (7.i9Gc) c m • o ® oo c I� � us GM ^ u o MD�OG�. o ® a7 / c > ay °. loa.n 1 / Q 139 0 Q I N •? r aR/p • Q1 �' Q to $ � Z am 4m O Y 1 .o Ie1 a 12a.o Q 320 329 328 J jl BOARDWALK DRIVE 259.2 ® a O THE FOUNTA I NHE4 PUD " L °. ® �JHF m ' 1ST FILING n'� c y ® •2 p ' v Is 155 175 = � C SJe.e W zz]010 s�2]5.9Y THE FOUNTA tYMEAD PUQ i ey PMASE II e 8 p Y i� �"�•- ® v o L ^ 125.0 165 I,l QOj a u• 125.0 S7. B0 � • '� I YY.Y 'O m •f FOUNTAINHEAD PUD �� ® ' an f PHASE -THREE •9j FIGURE I me BASIN _.AREAS .N «< eau. e1 I c I I I n I t] I U I L The recent construction of the Toys "R" Us site and Bockman Drive have altered these flows somewhat. Runoff from the South one-half of Bockman Drive and a portion of Basin D are now collected by a drainage swale where they are conveyed to the Larimer #2 Canal. It was intended that this would be a temporary condition until Basin D and the JFK Parkway developed. This area also falls within the limits of the Heart Special Improvement District (SID). Drainage criteria outlined as part of this district restricts runoff into the Larimer #2 Canal to a rate of 0.87 cfs/acre of developed area. DRAINAGE CRITERIA The Rational Formula was used to develop flows for this project. The Rational Formula is an excellent predictor of flows in basins less than 200 acres. DRAINAGE UNDER DEVELOPED CONDITIONS This 400' segment of the JFK Parkway is being constructed independently of any development projects. It is the intent of adjacent landowners to complete this rcatt vay to fulfill requirements which were part of the Toys "R" Us project. The drainage analysis and ' -3- A t proposed improvements therefore were developed to allow the drainage to functions properly once this section of roadway was completed and to include improvements which will allow future development to complete their drainage systems as well. In order to define these improvements, drainage basins A-J were developed as shown in Figure 1. A separate discussion of these individual basins follows: I ' BASIN A Basin A includes approximately 0.65 acres of roadway and right-of-way along the east side of the JFK Parkway from Bockman Drive south to the crest of the hill. This area will be graded as a part of this project but will not be paved. Runoff will continue to sheet flow from southwest to northeast and will be collected in a temporary detention facility on the east side of JFK. When development is completed on property to the east of the roadway this water will be diverted into permanent detention basins through inlets or driveways as part of the Lfuture development. Approximately 6.5 cfs will discharge from this area during the 100 year Istorm once street improvements are completed. 1 i 1 1 -4- 1 BASIN B Basin B includes approximately 0.67 acres of roadway and right-of-way along the west side of the JFK Parkway from Bockman Drive south to the crest of the hill. Existing runoff will continue to sheet flow from southwest to northeast and will not change as a result of this construction. As JFK is completed, this runoff will proceed to an inlet or driveway at the ' southwest corner of JFK Parkway and Bockman Drive. The water will be directed towards detention ponds to be built as part of the developments on the area west of the JFK Parkway and south of Bockman Drive (Basin D) in order to meet the 0.87 cfs per acre release rate requirements. Approximately 6.7 cfs will discharge from this area during the 100 year storm once street improvements are completed. BASIN C ' Basin C includes approximately 0.42 acres of roadway and right-of-way along the south side of Bockman Drive from the JFK Parkway west to the crest of the hill just west of Mitchell Drive. Existing runoff will be collected by the Bockman Drive Street curb ' and directed to an inlet at the southwest corner of the JFK Parkway and Bockman Drive. This runoff will be diverted under Bockman Drive into the Toys "R" Us detention facility. This area ` will be exchanged for Basin F which is the west one-half of the JFK Parkway adjacent to the Toys "R" Us site. Basin F was included in the drainage evaluation for the Toys "R" Us -5- i project; however, due to the final grades of the JFK Parkway it was not possible to divert Basin F into the Toys "R" Us detention system. BASIN D a c s 1 p ri ' dr fl d o o Basin D is the undeveloped area between Bockman drive, JFK Parkway and the top of ridge approximately 250 feet north of Boardwalk Drive. This triangular shaped basin ntains 5.1 acres and slopes from the southwest to the northeast. The construction of this egment of JFK Parkway will provide for a storm sewer which will be sized to accommodate ermitted historic flows from the site. When developed, Basin D will include the JFK street ght-of-way which is adjacent to the site and further identified as Basin B. A future inlet or iveway at the southwest corner of Bockman Drive and JFK Parkway will direct these street ws to future detention ponds. A separate storm sewer outfall will provide an outlet for the etention ponds. A summary of these flows follows: BASIN ' B D Total 1 AREA (ACRES) 0.67 5.10 5.77 ALLOWABLE RELEASE (0.87 cfs/acre) 0.58 4.44 M 5.02 DESCRIPTION West side JFK Development site These allowable releases are calculated based on the .87 cfs/acre release rate previously mentioned. A temporary detention pond will be constructed at the southwest corner of the JFK Parkway and Bockman Drive. An orifice plate with a 6 15/16" X 6 15/16" square opening will meter flows into the 15" storm sewer which will convey these flows to a temporary detention pond along the east side of the JFK Parkway. BASIN E Basin E is the easterly portion of the JFK Parkway from Bockman Drive north to the inlet at the Larimer #2 Canal. This basin is .36 acres and includes street improvements and right-of-way. This area is within the limits of the proposed construction. An in let at the north end of the basin will intercept street flows and direct them to temporary detention east of this project. These flows will be metered through an orifice plate before discharging into the Larimer #2 Canal. As this property is developed these flows will be diverted into a permanent ' detention system. BASIN F Basin F includes .44 acres and covers a small section of the north side of Bockman Drive and the west one-half of the JFK Parkway from Bockman Drive north to an inlet at the I Larimer #2 Canal. This basin was included in the drainage analysis for the Toys "R" Us/Western Auto P.U.D.; however, due to the grade of the JFK Parkway it is not possible to direct these flows into the Toys "R" Us detention system. An inlet at the Larimer #2 Canal will be built to intercept these flows where they will be conveyed via storm sewer to a temporary detention facility along the east side of the JFK Parkway. These flows, along with the flows from Basin E, will need to be included in permanent storm drainage detention ' facilities to be constructed when property east of JFK Parkway develops. BASINS G & H A small portion of the JFK Parkway right-of-way lies north of the Larimer #2 Canal. Basin G is the west one-half of the JFK Parkway and Basin H is the east one-half of the JFK ' Parkway north of the canal. Basin G is approximately .10 acres and Basin H is approximately .07 acres. This area flows to the northeast away from the Larimer #2 Canal. The flows from ' these two JFK Parkway basins will not be detained and will continue to flow to the northeast. As this section of the JFK Parkway is extended to the north and development occurs on the adjacent property, these flows can be diverted to future detention ponds. Slope paving and riprap have been utilized to reduce erosion from this runoff. I -8- 1 P ROPOSED STO R M II Ilo� II II�� II Ilga •� � Ilom ' o.to aceEo - 6 tgo Met- lio.2 uuA.L. ' t3X14Ttt..14c. eG'r4tt..,tu4 WALL- 1 r L uo09TAlLJe0 FL.Ow4x ir (a.00 Ot veL.oQeo) jaC110 G 1.6 G% 3�� N O.7 cf's Iter OG'ruwvD BY VwL ro" DNBL.OPYIEL r p�41N£O FL.oM�4 � �a0 pevELOPCO) BA61Li 8 t'v.7 eF4 peTe�uED W Pb.+o •A• 9 tLJ O 43.�cf3 9�tJ G 4.0 cfo lwwo*go ve otareurttoN B4ytyj A 40.5 CSOP OGTdtoQO to POU"' B�to E 0.4 CA-1 ,. .. w w IIII 9 14.1 F 4.4 cf+s w M ■ w 94sw J m4.7 cfi Uw0F_¢aeou"= 2GP Tir TO •�' tyj D6T6L]TIO� . BOGIG!'lAL1 De. oG Ftc.B Pt.ATE � i ,..:. oreu0 A Q IMPROVEMENTS —O.O% 6cZE.'S t- iL \ GooGeETE .,;t ? J t0 P. o tL £ P4 i t` ku u Ito 0 1 dd�jj 1 q rur0 lu w o hO'lt . ` u a P3 FLJTueE Oetv>= , 6.5 C46 �TO T'EYLP. OGTHLYrtO/.� or x a J W 04 &4.7 &A> F ;URE 2 BASIN J The area between JFK Parkway and Landings Drive and between the ridge line just north of Boardwalk Drive and the Larimer No. 2 Canal contains 7.19 acres. Currently, runoff ' sheet flows from south to north where it is intercepted by the Larimer No. 2 Canal. Basins A, E & F also will discharge through Basin J as JFK Parkway is completed and as Basin J is ' developed. A temporary detention pond will be constructed to collect flows from these Basins ' and release them into the Larimer No. 2 Canal at a controlled rate of 0.87 cfs/acre. In addition, flows from the temporary detention pond on the west side of the JFK Parkway will ' be routed through this temporary detention pond. A 12 3/4" X 12 3/4" orifice plate mounted on an outlet structure will restrict flows. This will allow all drainage runoff from the construction of the JFK Parkway, and from the two proposed development areas along the ' JFK Parkway to be discharged into the Larimer No. 2 Canal in one location at the allowed rate as requested by the ditch company. SUMMARY 1 ' PROPOSED STORM SEWER IMPROVEMENTS ' A proposed 15" storm sewer system will be installed in this phase of JFK Parkway (see ' figure 2) . This system will provide a drainage outlet for future development in Basin D as well as adjacent street improvements in Basin B. Basin B flows will be directed to the future -9- L development via driveways and a future inlet at the southwest corner of Bockman Drive and ' the JFK Parkway. Temporary detention pond "A" and an orifice plate controlled outlet will insure that this system will function properly with an allowed release of 5.02 cfs. Flows from Basin "C" will be directed into an inlet at the southwest corner of Bockman Drive and the JFK Parkway. This runoff will be directed into the Toys "R" Us underground ' detention via a pipe under Bockman Drive. ' Inlets at the north end of Basins E & F will direct runoff onto property east of the JFK Parkway where it will flow into temporary detention facility "B". Detention Pond "B" will also collect runoff from Basins A and J. Eventually this runoff will be included in a permanent detention system as the site is developed. An outlet from this pond will be built to allow ' flows from, both temporary detention ponds to be released into the Larimer No. 2 Canal. Riprap has been placed at the outlet to prevent erosion around the outlet pipe and inside the ' irrigation ditch (see attached calculations for sizing riprap). Also this site must detain for Basin F which is the west side of JFK. This is not a normal requirement since adjacent properties are normally only required to detain to the crown of adjacent streets. However, due to the site topography restrictions, this detention requirement will be imposed upon this site. In exchange for this, the usual site to be responsible, Toys "R" Us, will provide detention for Basin "C" (see Basin "C" discussion) -10- 1 I BASIN SUMMARY it BASIN AREA ato OIce PERMITTED COMMENTS (ACRES) (CFS) (CFS) RELEASE (0.87 CFS/ACRE) A. 0.65 3.5 6.5 0.57 DETENTION PROVIDED FOR IN POND B B 0.67 3.6 6.7 0.58 DETENTION IS ' PROVIDED FOR IN POND A C 0.42 2.0 4.0 0.37 DETENTION IS PART OF 1 TOYS "R" US SITE IN EXCHANGE FOR BASIN F D 5.10 - 45.9 4.44 PERMITTED RELEASE FOR BASIN B & D IS 5.02 CFS. DETENTION ' IS PROVIDED FOR IN POND A E 0.36 1.8 3.6 0.31 DETENTION IS PROVIDED FOR IN POND 1 e F 0.44 2.3 4.4 0.38 DETENTION IS ' PROVIDED FOR IN POND B .G 0.10 - 1.0 -- DETENTION IS PART OF 1 FUTURE DEVELOPMENT TO THE NORTH H 0.07 _- 0.7 --- DETENTION IS PART OF ' FUTURE DEVELOPMENT TO THE NORTH J 7.19 --- 64.7 6.26 PERMITTED RELEASE 1 FOR BASINS A, E, F & J IS 7.52 CFS. DETENTION IS PROVIDED FOR IN POND B ' TOTAL 15.00 i 1 DRAINAGE STUDY, by TST, FOR SHOPKO �J I I I I iLI LJ HISTORIC CONDITIONS This site has a high point located near the center of the property and slopes down from there in all directions. Runoff to the south and west is collected by College Avenue and ' Boardwalk Drive and directed to a curb inlet near their intersection. Runoff to the north is collected in Bockman Drive and -directed east towards the proposed JFK Parkway. It is then ' collected by a curb inlet in Bockman Drive and directed into the Toys "R" Us underground detention facility. Runoff to the north sheet flows overland to the Larimer #2 Canal. Figure 2 shows the existing drainage pattern. The site is moderately vegetated by rangeland grasses and weeds with some bushes and trees present. The northeast portion of the site is littered with spoil piles from adjacent ' construction. There are currently three businesses operating on the site. A travel agency and a feed store are located next to each other in the northwest portion of the site adjacent to College Avenue. An automotive repair shop is located on top of the hill in the central f t west portion of the site. All of these facilities will be abandoned and removed as part of this project. ' The drainage reports for the Toys "R" Us store and the Western Auto store, as well as the ` drainage report for the extension of the JFK Parkway to Bockman Drive, mention the contributing portion of this site. The extension of JFK Parkway to Bockman Drive project r , includes a temporary detention pond with a capacity of over 36,000 cubic feet (0.83 ac/ft) ` and a restricted release structure which is to allow a flow of 5.02 cfs. The pond is to be ' located in the southwest corner of the JFK-Bockman intersection and outfalls into another [ pond, via a 15" RCP under JFK, at the northeast corner of the intersection. This pond I outfalls into the Larimer #2 Canal via a restricted release structure. The portion of this site ' which contributes to this condition is approximately 5.8 acres which includes the west half f of the proposed JFK Parkway extension from Bockman Drive south to the crest of the hill r (which will be constructed as part of this project). J • i ( i OZZ< W ZOu, 0 i ( j y rQW • <Zx0 W , i I i mOW�m..oc n OVWOOQ v .icm- o cu. cc 0 F-WZWZZ 21-3 a;3 .%: ' KF-OOocO-+ dy W ILO O SANTJ•• I I �I �j I DEVELOPED CONDMONS PLAN DESIGN CRITERIA ' The drainage system presented in this report has been developed in accordance with the guidelines established by the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual (SDDC) dated May, 1984 and revised in January, 1991. Where applicable, design guidelines and information were also obtained from the Denver Regional Council of Government Urban Storm Drainage Criteria Manual (USDCM). 1 The Master Storm Drainage Report for the Landings P.U.D. dictates a discharge rate of 0.87 cfs/ac for release into the Larimer #/2 Canal. Because of this mandate, the historic flows ' across the site were not calculated. Developed condition storm facilities were designed based on the 10-year and 100-year storm frequencies as dictated by Table 3-1 of the SDDC manual. Since the I00-year storm will produce flows in excess of 0.87 cfs/ac, on -site ' detention facilities will be required. The same method used for sizing the detention facilities for the Toys "R" Us and Western Auto stores and for the JFK Parkway extensions was used ' since some of these facilities are inter -related. Due to the limited size of the sub -basins on the site, the Rational Method was selected to ' calculate runoff. The Rational Method utilizes the SDDC Manual equation: Q = CtCIA ' where Q is the flow in cfs, A is the total area of the basin in acres, Cf is the storm frequency adjustment factor, C is the runoff coefficient, and I is the rainfall intensity in inches per hour. The runoff coefficient, C, was selected to be 0.95 which is dictated by Table 3-2 of the SDDC manual (for BB zoning). The frequency adjustment factor, Cf, is given in Table 3-4 of the SDDC manual and was 1.0 for the 10-year storm and 1.25 for the 100-year storm. ' Since the SDDC manual indicates the product C x Cf shall not exceed 1.0, 1.0 was used as the product when calculating 100-year storm flows (0.95 x 1.25 > 1.00). The appropriate rainfall intensity was taken from the rainfall intensity duration curve in the SDDC Manual (Figure 3-1). To obtain the rainfall intensity, the time of concentration had to be determined. The following equation was utilized to determine the time of concentration: '= +4 ' where t, is the time of concentration in minutes, t; is the initial or overland flow time in minutes, and t is the travel time in the ditch, channel or gutter in minutes. The initial or overland flow time was calculated with SDDC Manual equation 3.1.7: t; _ [1.87(l.1 - CC)0.5]/(S)0.33 5 I ( ' where L is the length of overland flow in feet (limited to a maximum of 500 feet), S is the average basin slope in percent. This procedure for computing time of con entratichannels, for overland flow as well as travel time for runoff collected in streets, gutters, pipes or ditches. DRAINAGE PLAN DEVELOPMENT — ' The proposed drainage plan for the development consists of a combination of sheet flow, across a paved parking lot, collection into inlets, and conveyance to and from detention facilities via storm sewer pipe. This project will also include construction of the west half of JFK Parkway from Boardwalk Drive to Bockman Drive. Street flows for this portion of the site will be calculated based on encroachment criteria set forth in the SDDC manual for an arterial roadway. The other three streets which bound the site will also be evaluated ' based on the SDDC criteria set forth for their respective classifications. Although this site lies in two major drainage basins, the City of Fort Collins Stormwater Utility is requiring that all runoff from the site be detained and then released into the Larimer lit canal. Temporary facilities are currently under construction as part of the JFK Parkway ch is extension to Bockman he Bockmde two etention an Drive and JFK Parkway.oThis pond on the ShopKo site at the southwest corner of kman is referred to as Pond "A" in the JFK Parkway Drainage Report. The other pond is referred ed to as Pond "B". In that report, at a me of 5 02 cf's via a 15" RCPpKo mto site "B" to beToavoid in Pond "A" and released obtaining a separate release permit into the Larimer #2 Canal to accommodate the remainder of the ShopKo site, it was decided to detain all runoff and release it through Pond "A" at the predetermined rate of 5.02 cfs. PROPOSED DRAINAGE PLAN Preparation of the drainage plan required the delineation of sub -basins within the development. It should be noted that the labels for the sub-basins however, the the drainad storm drainage e p an E facilities has changed considerably from the preliminaryreport; has changed very little. The grading and drainage plan can be found at the end of this report and shows the sub -basin delineation and proposed storm drainage facilities. Calculations made for flow, inlet, detention pond, pipe analysis, street capacity and riprap design can be found in the Technical Appendix. The results of these calculations futh Proposed can Dfrainag P� for les 4 5 and 6 at the end of this section. A summary 1, 2, sub -basin . each sub -basin is provided in the following Paragraphs Sub -basin A includes runoff from the parking lot and future building pad on the south side ' of the ShopKo building. Runoff will sheet flow around the east and west sides of the future building pad and directed into swales in the Parking lot. A Swale on the east side of the pad 6 will direct runoff directly to area Inlet ##1. A combination of swale and gutter flow will also direct runoff to Inlet i#1. Critical sections in the swales were checked to insure that runoff would not leave the site or spill into adjacent sub -basins. This check was also needed to insure that emergency vehicles could gain access to the future building during the 100-yr storm. Inlet ##1 will be an area inlet in a sump condition. To maximi�p the inlets efficiency runoff will be allowed to pond to a depth of 0.63 ft. (top of curb). The developer is currently negotiating with a potential owner for the building site in this sub -basin and it is anticipated that it will be built concurrently with the ShopKo site. In case there is a delay, this area will be rough graded to insure the runoff will be directed to the inlet. The surrounding curb and gutter and a temporary asphalt trickle pan designed to carry the 2-year storm will be installed. It is also possible the new owner will want to reconfigure the interior curb and gutter. This should not be a problem as long as the runoff is allowed to travel around both sides of the building and not concentrated any more than it is now along the southwest portion of the building pad. Sub -basin B collects parking lot runoff adjacent to the southeast portion of the ShopKo building. Runoff will be directed to curb Inlet ##2, which is in a sump condition, via sheet flow and gutter flow. Runoff can only be allowed to pond to a depth of 0.40 ft to insure that it doesn't spill over into Sub -basin C. Sub -basin C collects runoff from the remaining parking lot area on the east side of the ShopKo building and from the west half of the JFK ROW from the top of the hill to bockman drive. The runoff will be directed to Inlet ##3 which is a 35 foot continuous grade curb inlet. The inlet will intercept 100 % of the 100-year storm. Sub -basin D is a landscaped strip between the north side of the ShopKo building and the Bockman Drive ROW. Runoff from this area will sheet flow into Bockman Drive and be collected at Inlet #/4 which is a 4-foot continuous grade curb inlet. The street flows have been dealt with in the Toys-R-Us drainage plan and will be collected by an existing inlet and directed into the Toys-R-Us detention facility. Sub -basin E is the east pond. This pond is referred to in the JFK Drainage Report as Pond "A". Final design of this pond differs from the JFK Pond "A" in configuration and capacity but the release rate will be maintained as well as the pipe alignment and release structure. MThis pond accepts runoff from Sub -basins A, B, C, D, E, and L. It will also receive the release from the west pond. The outlet will release at a rate of 5.02 cfs and the 100-yr ponding depth will be 8.93 feet (EL = 36.31), top of pond EL = 39.0, and there will be 2.69 foot of freeboard. Sub -basin L will collect runoff from the west half of the JFK Parkway ROW between the top of the hill and Boardwalk Drive. Runoff will be directed to Inlet #/5 via curb flow. This inlet is a continuous grade curb inlet which will intercept 2.21 cfs while 0.55 cfs will pass during the 100-yr storm. The passing flows will enter Boardwalk Drive in Sub -basin M which will be discussed later. 7 Sub -basin F encompasses the southwest quarter of the parking lot. Runoff will sheet flow to swales which will direct flows to Inlet #/6. This inlet will be an area inlet in a sump condition with a maximum ponding depth of 0.77 ft. The capacity of the swales was checked to insure runoff would not spill over into Sub -basin N. Sub -basin G encompasses the northwest quarter of the site and will direct runoff, via sheet flow and swales to Inlet P. This inlet will be an area inlet in a sump with a ponding depth of 0.73 ft. The capacity of the swales was checked to insure runoff would not leave this sub - basin. Sub -basin H is the roof of the ShopKo building. ShopKo has indicated downspouts will be provided at the northeast and southeast corners of the building. Because of the capacity restraints of the east pond, it was necessary to pipe all of this runoff to the west pond. ShopKo could not provide actual expected percentage of flow in each downspout so it was assumed each would carry half. Sub -basin I is the west pond which will collect all of the runoff from Sub -basins F, G, H, I and N. 100-yr ponding depth will be 8.59 ft (EL = 40.59) with 1.41 feet of freeboard. This pond will release to the east pond via a 12" RCP which will carry 2.50 cfs. This pipe is smaller than the City's 15" minimum, but a 12" pipe controls the release rate without having an orifice plate. This condition would also constitute a variance from the City criteria. Sub -basin N is another future building pad located in the southwest comer of the site. All of the runoff will be directed to Inlet ##6 during overlot grading, via swales which were checked for capacity. The developer is currently negotiating with a potential owner for this building pad and it too will probably be built in conjunction with the ShopKo site. The surrounding curb and gutter and a temporary asphalt trickle pan design to carry the 2-year storm will be installed. If it were absolutely certain that this site would be constructed along with ShopKo, it would not need to be considered a separate sub -basin. We did this mainly to address erosion concerns if it is not developed with the rest of the site. Refer to the Erosion Control section of this report. Sub -basin J, Kl, K2 and M are all half ROW sections adjacent to the ShopKo site. Sub - basin J is the south half of the Bockman Drive ROW from the north entrance to ShopKo to College Avenue. Runoff will gutter flow to College where it will join runoff from Sub -basin K1 (100-yr combined flow = 3.86 cfs dev., 3.82 cfs hist.) and cross Bockman via a gutter pan and continue north in College Avenue undetained. Sub -basin K2 is the remaining portion of the college Avenue ROW and a landscaped strip on the west side of the ShopKo site. This runoff (100-yr flow. = 9.94 cfs) will continue south on College to Boardwalk Drive, undetained, where there are currently 4-foot curb inlets on both sides of Boardwalk which will intercept some of these flows. The remaining runoff will join runoff from Sub - basin M (100-year combined flow = 18.13 cfs dev.,, 22.38 cfs hist.) and continue south on College. Sub -basin M is the north half of the Boardwalk ROW and a portion of the south 9 entrance to ShopKo. The southern limit of this basin boundary is actually an arbitrary line (center line of the road) since this street has no crown. Undetained runoff will sheet flow across the street (from north to south) from the intersection at JFK Parkway down the hill to College Avenue. Because of this street's cross slope, it would be impossible to intercept these flows from the north side of the street. Currently, runoff either enters the Fountainhead P.U.D. at a driveway entrance opposite ShopKo's south entrance or continues west along Boardwalk to College Avenue. EROSION CONTROL There should be no erosion occurring on this site once construction is completed since 90% of the site will either be asphalt. or building. The remaining 10% will be sodded landscaping. If the two additional building pads are not constructed concurrently with the ShopKo site they will be reseeded and mulched. During construction, erosion will be a concern because the entire site will be disturbed. The general grading of the site is such that nearly all of the runoff will be contained within the site. During construction, gravel filters will be installed around all of the inlets. Since the majority of the site drains to sumps, the ponding created by the filters will allow sediments to fall out before they enter the storm sewer system. If the filters become inundated during a major storm and do allow sediments to pass all of the stormwater collected from this site must pass through at least one pond where the remaining sediments can fall out. The north side of the ShopKo building has a 3:1 fill slope which spills out onto Bockman Drive. This is the most erodible area on the site. Eventually, this slope will be sodded, but in the interim, a silt fence will be installed at the toe of the slope and the natural east falling slope will direct excessive flows to the east pond. ShopKo has indicated that they will start construction of their building in August. They will require that the overlot grading not only be completed, but that all except the final lift of asphalt be in place before they begin work on their building. This means that the site construction must be completed in less than two months because the developer intends to sign the Notice To Proceed around the first of June. Both ShopKo and a local contractor have indicated that the overlot grading can be completed in 30 days at which time curb and gutter can be installed and base course put into final grade. Paving operation should begin within one week of final overlot grading. VARIANCES As mentioned earlier, the northeast 5.77 acres of this site currently discharges to the Larimer ' #2 Canal. The remaining 5 acres (not including road ROW) discharges onto College Avenue. With this development, 5 acres of contributing runoff will be removed from College Avenue (and whatever facilities exist downstream) and directed to the Larimer N2 Canal. This will be done with an increase in actual volume of runoff, but at the flowrate (5.02 cfs) established for the existing 5.77 acres of contributing area. In essence, we are releasing 10.71 acres with an allowable discharge of 9.32 cfs (.87 cfs/ac.) at a rate of 5.02 9 cfs. This will insure that the system downstream of this site will not be taxed by flow from an un-historic contributing area. Intercepting flows in Sub -basins J, Kl, K2 and M will be difficult because all of these sub - basins are on continuous grades and curb inlets in a continuous grade are not very efficient. To intercept 100 % of the flows in these sub -basins, we have calculated (see Appendix B) that Sub -basin J will require a 13-ft inlet; Sub -basin Kl, a 10-ft inlet; and Sub -basin K2, a 15-ft inlet. Intercepting flows on the north side of Boardwalk would be nearly impossible because the runoff sheet flows across the street. Directing flows from Sub -basins J, Kl and K2 into the west pond will eliminate all freeboard and push the ponding depth up to an elevation at or exceeding the gutter flowline elevation at the corner of Bockman and College so pond water would actually run backwards through the inlet and discharge on the street (during the 100-yr storm). Our calculations indicate that on all of these streets, the 100-yr flow doesn't exceed the encroachment or capacity criteria for a 10-yr storm. Further more, the last few pages of Appendix A show a quick analysis of the existing releases from this site onto the intersections of College and Boardwalk and College and Bockman. Our analysis at College and Boardwalk indicates an existing 100-yr release of 22.38 cfs. The proposed drainage plan will only release 18.68 cfs, an improvement of 3.70 cfs. At College and Bockman, we have calculated an existing 100-yr release of 3.82 cfs. The proposed drainage plan releases 3.86 cfs, virtually no change from the existing flow. Based on the information we have presented, we request that runoff from Sub -basins J and Kl (3.86 cfs) and Sub -basins K2 and M (18.13 cfs) be allowed to discharge undetained. We also request that the flow passing the proposed 15 ft inlet in Sub -basin L (0.55 cfs) be allowed to release undetained. Finally, we would also request that a 12" RCP be allowed between the west pond and the east pond. 10 SITE HYDROLOGY [l I ` I � I �I \ I \ \ , I , ` I \ , I , \ , I I I 1 , \ 1 I r -i l i I I II 1 I I 61 I 61 1 I It I r' I I I `\ �'�\ VI 1 \ " \ 1 j I �� •9 ` i I , . I / ; I I It � --1 i ., r__ \-----------I------------------------ 8! I -�-J I I i I 1 I I I I I J I I 1 I I I I Developed Runoff Coefficients for Landings Bay Prepared by Bud Curtiss - Northern Engineering Date: February 3, 1999 Revised File: CYFCompC.wb2 Basin Area Imperv. Pervious C Imper C Pery Comp C No (ac) Area (ac) Area (ac) C1 1.05 0.90 0.15 0.95 0.35 0.86 C2 0.57 0.41 0.16 0.95 0.35 0.78 C3 1.21 0.89 0.32 0.95 0.35 0.79 C4 0.17 0.12 0.05 0.95 0.35 0.77 C5 0.74 0.64 0.10 0.95 0.35 0.87 C6 0.34 0.21 0.13 0.95 0.35 0.72 C7 0.04 0.04 0 .0.95 0.35 0.95 C8 0.95 0.18 0.77 0.95 0.35 0.46 LC1 1.03 0.00 1.03 0.95 0.35 0.35 D2 0.30 0.26 0.04 0.95 0.20 0.85 D3 0.19 0.15 0.04 0.95 0.35 0.82 LD2 0.20 0.17 0.03 0.95 0.35 0.86 JFKI 1.13 0.92 0.21 0.95 0.35 0.84 JFK2 0.44 0.44 0.00 0.95 0.35 0.95 NET SITE 8.36 5.33 3.03 0.95 0.35 0.73 Cl-8 (exclude C6) 4.73 3.18 1.55 0.95 0.35 0.75 JFKl 1.13 0.92 0.21 0.95 0.35 0.84 JFK2 0.44 0.44 0.00 0.95 0.35 0.95 COMP C 6.30 4.54 1.76 0.95 0.35 0.78 TO POND N O � z O Z z U O U LL O W F O r en 93 0 z O Wy m N N F m a C rs cU m } m O� D ¢ co E E E E E E E E E E E E E E E E E E E E E > > > > > > > > > > > > > > > > > > > > > E E E E E E E E E E E E E E E E E E E E E N E C C C C C C C E 'E *E *E C C E 'E C C C c c 'E Y E E E E E E E E E E E E E E E EE E E E a o m m m g m m o o S.S m L m 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 3> >> 7 C c c C C C c c C C C c c C C C C C C C C W EE E EEEEEEE'EE EEEEEE E E E UO LO t0 WO 10 WO 10 10 MO UO LO N LO 10 N UO WO 9) WO 10 10 W W W 0co cc Wmm Wmm Wmm pWp pWp mWm mWm 0W mWm mWm mWm mWm mWm mWm N N N N N 0 N N N N N N N N N N mN s s 0 77 7 777777777 777777 >>7 O O f� 0! 0 0 0 O O O O O O O I I O m to 0 0 0 0 0 0 N O O O QJ H N N N h h (6 N h N N h IN U) h W C4000f 1A N N N 16 wi(d wi In 10 Z LL E W W O m m O m m O 0 m W F r U U U ¢ ¢ Q Q U3 0 0 0 0 S ug ad re adz z z z ♦e ro ro oe re ¢ f -E -q -e -e - F Q U U U U U U U U U ll P 1010 UO UO R qt 0) m O O O O O O O 0 WO LO N N f0 f0 0WO WO OO CCC G GNNOO GGYY �. Eo H 00000 0 U0 U0 N101010 W 1010 fl h 0000 U0 Un MM Ol l7 U m NNCV NNN��(O {9�����-•-��NNCV N�7/9 tb (O l9 W _j LLI > J W 0000000000000000000000000000 0000000000000000 r r 000 000 1,r�r- � W O�^ O NNr- NNOO 1:1�,h NNNNN IL N = O O 0 O t O l O l O N 0 0000000000 o S O O O O O O oO aD aD cO COQ Y��NN f�l�'1NN�� OOD OD /h Z F � W J mN�o1��v�ar��ovmr��.v�mrcm��vNm�eomro ���GGO>�C « fV� V Mr' 19��04 NN6N6 C O WF.9Ew F z WL O O O 0000000000000000000000000 00000000000 0 0 0 0 0 0 0 0 0 0 0 000000 66 N N N NNN QC JW O N N N (V Nei N C%i N N � 1 IV �-�r-N N N v y 0 = NN N N N N OO �O �000�0 �00000 �O �000�01000 �O �O �� fO fD rr`R V �O iONN��r`Aa0 GO t0 tONNfO fONNf0 f7 r-� H . Z W J 10l, n n n CR CR n rl N7 V 1(9 f9 f00. CO a ND. CRa0 aD c00/ W aO aD�� 0000000000000000000000066666 m u,in.���nc��igg�i,�oo�ic9ir'°'�i�i��$ ¢ Q ¢ W v N 0 0 � O N N , � .�6O , � O O O O O O O O O O , , O O O O O O " O O Q z N .. ¢ O ♦ CO W ♦ • (�(♦� ♦ 101r0♦{Qp ♦ pppp(♦pQp �-� r (�♦ NNY'YY UJ OJ L LLLL yU (iUUUUCJ��UUCJU UUUUJJ00�0 IX ||§/! !!laaa2 )!m!! 3§72C3 0ee■2ee ==w0=0 ram;; )&2 )/R §§� E§f, 0:;;«=w;;22;: 46;N��2 ■§I` 61 . , =mG �Ka, !! g!! (o wa N0 kj� 15:c;c; mm|!||§§|!! §!!|!!! - \{. ;;,� !!§!55!§!S§§! o 6666066 :`;:::: ; [Ik` ; §k{� 2Kk` § ~ k , $k 22Q 6 6 -6 \;&;�66 Kw32|2§ .§ f-iKIOXIJZA\_ � � z ; � l.f,I„ 2f\§f• `®|J$$$(|![k! ////kk|!ƒ/J| W)�R �w{; §\\` �§#e =IT—q IT 2 =;;__:_ � � � (i# ■§«� 0 ;A � =mp §\ &22, !! q!■ §§#e ;=:;em:;;=;'d §k#© :;;_!:Ir ;=::5;;:;=6@_ �Z¥; §§§5355§!!6!! 05:!!!§ m!!!§!!3!!!!! !§!!!!! - (° ` |!§f§§§@§S|S! |!S!!§! o � ;;;_:;; ) �{�»=::_:;;:; w \kk� 2kk` W. Cli It ) \ , �k 22&3 k(};§2) a\# 32&33& & OVERFLOW - BASIN C-1 TO JFK BLVD Worksheet for Irregular Channel �I Project Description Project File c:\drainage\haestad\fmw\courtyar.fm2 Worksheet OVERFLOW Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation Input Data Channel Slope 0.020000 fttft Elevation range: 49.36 ft to 50.31 ft. Station (ft) Elevation (ft) Start Station End Station 0.00 50.31 0.00 24.00 0.00 49.81 24.00 49.36 24.00 49.86 Discharge 10.20 cfs Results Wtd. Mannings Coefficient 0.016 Water Surface Elevation 49.68 ft Flow Area 2.68 ft2 Wetted Perimeter 17.24 ft Top Width 16.92 ft Height 0.32 ft Critical Depth 49.75 ft i% Critical Slope 0.006592 f 1ft �1 Velocity 3.80 ft/s Velocity Head 0.22 ft Specific Energy 49.90 ft Froude Number 1.68 Flow is supercritical. IN 02/02/99 02:27:58 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Roughness 0.016 FlowMaster v5.13 Page 1 of 1 OVERFLOW BASIN C-2 TO C-5 Worksheet for Irregular Channel Project Description Project File c:\drainage\haestad\fmw\courtyar.fm2 Worksheet OVERFLOW - BASIN C-2 Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation Input Data Channel Slope 0.006000 f lft Elevation range: 42.40 ft to 42.75 ft. Station (ft) Elevation (ft) Start Station 0.00 42.73 0.00 22.00 42.40 42.00 42.75 Discharge 5.00 cfs Results Wtd. Mannings Coefficient 0.016 Water Surface Elevation 42.62 ft Flow Area 3.02 ft2 Wetted Perimeter 27.35 ft Top Width 27.35 ft Height 0.22 ft Critical Depth 42.61 ft Critical Slope 0.007910 f fft Velocity 1.66 ftis Velocity Head 0.04 ft Specific Energy 42.66 ft Froude Number 0.88 Flow is subcritical. ovovss 02:34:43 PM End Station Roughness 42.00 0.016 FlowMaster v5.13 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 41 1, OVERFLOW BASINS 3,4,5 Worksheet for Irregular Channel Project Description Project File c:\drainage\haestad\fmw\courtyar.fm2 Worksheet NEW OVERFLOW C3,4,5 Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation Input Data Channel Slope 0.028600 ft/ft Elevation range: 32.80 ft to 35.10 ft. Station (ft) Elevation (ft) Start Station 0.00 34.00 0.00 12.00 32.80 14.50 14.50 33.40 21.00 21.00 33.40 28.00 32.90 37.50 34.00 42.00 35.10 Discharge 24.50 cfs Results Wtd. Mannings Coefficient 0.049 Water Surface Elevation 33.56 ft Flow Area 9.89 ftz Wetted Perimeter 29.51 ft Top Width 29.34 ft Height 0.76 ft Critical Depth 33.50 ft Critical Slope 0.057110 ft/ft �. Velocity 2.48 ft/s Velocity Head 0.10 ft Specific Energy 33.66 ft Froude Number 0.75 Flow is subcritical. Y End Station 14.50 21.00 42.00 06/07/99 01:49:37 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Roughness 0.060 0.016 0.060 FlowMaster v5.13 Page 1 of 1 11 SITE DETENTION I, 11 I �1�-TZa at�rr,�av-1,.e�n J F I -.I J F- k Z - o_. 444 tt \ 0 -7 ,�' �`l/S - l OT�L TD w�] M 1✓1� lVo. Z - I Z -�S Q' C Pb,ex�a,lay v� Pave—= 70 L oz-1 t-EQ klc>. z cz,L� j`iPL1.SS �(ZDM 5�0P1� �. C:::>Z L LANDINGS BAY - DEVELOPED RUNOFF B Curtiss February 1999 Northam Engineering Services Allowable Developed Developed Total Undetained Allowable Time i100 Release to Basin C-6 Basin LC-1 flows to Release from (min) (in/hr) Ditch (cfs) Excluded (cfs) Excluded (cfs) Ditch(cis) Pond (cis) 5 9.00 7.52 2.75 2.11 , 4.86 2.66 10 7.20 7.52 2.20 3.24 5.45 2.07 15 5.95 7.52 1.82 2.68 4.50 3.02 20 5.20 7.52 1.59 2.34 3.93 3.59 25 4.60 7.52 1.41 2.07 3.48 4.04 30 4.15 7.52 1.27 1.87 3.14 4.38 35 3.80 7.52 1.16 1.71 2.88 4.64 40 3.50 7.52 1.07 1.58 2.65 4.87 45 3.25 7.52 0.99 1.46 2.46 5.06 50 3.00 7.52 0.92 1.35 2.27 5.25 55 2.80 7.52 0.86 1.26 2.12 5.40 60 2.60 7.52 0.80 1.17 1.97 5.55 70 2.30 7.52 0.70 1.04 1.74 5.78 80 2.05 7.52 0.63 0.92 1.55 5.97 90 1.87 7.52 0.57 0.84 1.41 6.11 100 1.70 7.52 0.52 0.77 1.29 6.23 110 1.57 7.52 0.48 0.71 1.19 6.33 120 1.45 7.52 0.44 0.65 1.10 6.42 150 1.20 7.52 0.37 0.54 0.91 6.61 180 1.05 7.52 0.32 0.47 0.79 6.73 r I \ \ 4.� c-L JFKZ 1 f 1 i n I DETENTION POND SIZING BY FAA METHOD Developed by Dr. James Guo, Civil Eng. Dept., U. of Colorado D F Denver Urban Drainage and Flood Control District, Colorado ---------- ----------Supported-by-Denver-MetroCities/Counties-Pool-FundStudy USER=NORTHERN ENGINEERING SERVICES INC FT. COLLINS COLORADO .............................. EXECUTED ON 02-02-1999 AT TIME 09:15:58 PROJECT TITLE: LANDINGS BAY **** DRAINAGE BASIN DESCRIPTION BASIN ID NUMBER 1.00 BASIN AREA (acre)= 6.30 RUNOFF COEF 0.98 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 100.00 INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 80 100 120 150 180 INTENSITY 9.0 7.3 5.2 4.2 3.5 3.0 2.6 2.1 1.7 1.5 1.2 1.0 ***** POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE = 2.07 CFS OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE = 2.07 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. ***** COMPUTATION OF POND SIZE ------------------------------------------- RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED DURATION INTENSITY VOLUME VOLUME STORAGE MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT 0.00 0.00 0.00 0.00 0.00 5.00 9.00 0.39 0.01 0.37 10.00 7.30 0.63 0.03 0.60 15.00 6.25 0.80 0.04 0.76 20.00 5.20 0.89 0.06 0.83 -- 25.00 4.70 1.01 0.07 0.94 30.00 4.20 1.08 0.09 0.99 35.00 3.85 1.16 0.10 1.06 40.00 3.50 1.20 0.11 1.09 45.00 3.25 1.25 0.13 1.13 50.00 3.00 1.29 0.14 1.14 55.00 2.80 1.32 0.16 1.16 60.00 2.60 1.34 0.17 1.17 65.00 2.47 1.38 0.19 1.19 70.00 2.35 1.41 0.20 1.21 75.00 2.22 1.43 0.21 1.22 80.00 2.10 1.44 0.23 1.21 85.00 2.00 1.46 0.24 1.22 90.00 1.90 1.47 0.26 1.21 95.00 1.80 1.47 0.27 1.20 100.00 1.70 1.46 0.29 1.17 105.00 1.65 ------- --1�49------0-30------1�19 �i� THE REQUIRED POND SIZE = 1.21711 ACRE -FT c THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 75 MINUTES 11 I L, I I 00 C.0 00 co -.4- N (7) o') O 00 OR DR OR 0 O C; O 0 0 0 0 JOIOII d. -lu;)T-Xxl-snr 13V AA.0ullio a I DETENTION POND HIGH WATER LINE Landings Bay PUD -Existing Detention Pond 53,017.0 = REQ. VOLUME CONTOUR AREA AVG AREA INTERVAL CUMULATIVE HIGH WATER Contour Storage (sq.fL) (sq.ft.) VOLUME (cu.ft.) VOL (cu.ft.) LINE (ft.) 25.8 100.0 1,947.5 240.1 240.1 25.8 0.0 26.0 3,795.0 0.0 26.0 0.0 6,548.0 6,345.7 6,585.8 27.0 9,301.0 0.0 27.0 0.2 10,348.5 10,330.8 16,916.E 28.0 11,396.0 0.0 28.0 0.4 12,243.5 12,233.7 29,150.3 29.0 13,091.0 0.0 29.0 0.7 14,301.0 14,283.9 43,434.2 30.0 15,511.0 30.6 30.0 1.0 16,694.5 14,678.8 58,113.1 30 9 17878.0 0.0 30.9 1.3 ' NOTES: 1. FOR THE FIRST CONTOUR VOLUME A CONIC SHAPE WAS ASSUMED VOL. = 1/3 (AREA ABOVE) (DIFFERENCE IN CONTOUR ELEV.) 2. FOR THE REMAIMDER OF THE VOLUMES BETWEEN CONTOURS (SECTION 9.2) VOL. = DEPTH/3 (A +(AB)A.5 + B) FOR: Uniform Sides sec.(9.2) 3. HWL=(VOL.REQ: VOL.LOW CUML)-3/(AREA LOW+AREA HIGH+(low area high area) A.5) 30.57 = HWL POND 'ORIFICE SIZING ORIGINAL DESIGN DATA 2.07 = Allowable Des. Release Rate(cfs) 25.00 = Tailwater Elevvbon 0.60 = Orifice Coefficient (Cd) 5.57 = Available Driving Head(ft) 25.81 = Flowline Elevation VERT. CIRCULAR PLATE 26.81 = Outlet Area(inches) 2.92 = Circular radius(inches) 5.33 = Actual Hydraulic Driving Head(ft) VERT. SQUARE PLATE 26.22 = OutletArea(inches) 5.12 = Side for Sq. Opening(inches) 5.36 = Actual Hydraulic Driving Head(ft) HORZ. CIRCULAR PLATE 26.22 = Outlet Area(Inches) 2.89 = Circular radius(inches) 5.57 = Actual Hydraulic Driving Head(ft) NOTE: 1. VERT. PLATES WILL BE PLACED AT PIPE FLOWLINE 144 IZ Strom 42.44, CJAIL "IQcl.� 4-7.4Z_ i 3=�-gS Q = 4-.4Z -4 = p . ZE3 -4-7.4Z • use. Ioc� � m�,J x o•z� PROJECTo��$�JOB NO. 1 r r CLIENT Prz�L)T�� CALCULATIONS FOR MADE BY r DATE CHECKED BY r DATE SHEET OF FORT COLLINS, COLORADO 80521 L,n.ti�5can� M�Dloa..l bssunnc 'oM-6.r 1 = -'t_ -°• .ADD (p�`-PLL�.l�W1�►:1'I`"--� U,9`�J - 1 - Lf= OP ;� �8�' ��� � = _ . _�►� sue__.__.---_---__.___: _ __._____�: _ .._--__-_ +lOLx> 2 , 057 .4s n, , ��e.e�� ���.. c� v.i/ Ic, �4 �-GoZ.o� �1.1T1 SL.� L►F �LC�T7.� O� Go i..�Te, l f�u'n r�16 , i Ll DETENTION POND SIZING BY FAA METHOD Developed by Dr. James Guo, Civil Eng. Dept., U. of Colorado Supported by Denver Metro Cities/Counties Pool Fund Study Denver Urban Drainage and Flood Control District, Colorado ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ USER=NORTHERN ENGINEERING INC FT. COLLINS COLORADO .............................. EXECUTED ON 04-12-1999 AT TIME 15:29:25 PROJECT TITLE: LANDINGS BAY **** DRAINAGE BASIN DESCRIPTION ' BASIN ID NUMBER 1.00 BASIN AREA (acre)= 6.42 RUNOFF COEF 0.98 ***** DESIGN RAINFALL STATISTICS DESIGN RETURN PERIOD (YEARS) = 100.00 INTENSITY(IN/HR)-DURATION(MIN) TABLE IS GIVEN DURATION 5 10 20 30 40 50 60 80 100 120 150 180 INTENSITY 9.0 7.3 5.2 4.2 3.5 3.0 2.6 2.1 1.7 1.5 1.2 1.0 ***** POND OUTFLOW CHARACTERISTICS: MAXIMUM ALLOWABLE RELEASE RATE = 2.07 CFS OUTFLOW ADJUSTMENT FACTOR = 1 AVERAGE RELEASE RATE = 2.07 CFS AVERAGE RELEASE RATE = MAXIMUM RELEASE RATE * ADJUSTMENT FACTOR. ***** COMPUTATION OF POND SIZE -------------------------------------`--------------- RAINFALL RAINFALL INFLOW OUTFLOW REQUIRED DURATION INTENSITY VOLUME VOLUME STORAGE MINUTE INCH/HR ACRE -FT ACRE -FT ACRE -FT ----------------------------------------------------- 0.00 0.00 0.00 0.00 0.00 5.00 9.00 0.39 0.01 0.38 10.00 7.30 0.64 0.03 0.61 15.00 6.25 0.82 0.04 0.78 20.00 5.20 0.91 0.06 0.85 25.00 4.70 1.03 0.07 0.96 30.00 4.20 1.10 0.09 1.02 35.00 3.85 1.18 0.10 1.08 40.00 3.50 1.22 0.11 1.11 45.00 3.25 1.28 0.13 1.15 50.00 3.00 1.31 0.14 1.17 55.00 2.80 1.35 0.16 1.19 60.00 2.60 1.36 0.17 1.19 65.00 2.47 1.41 0.19 1.22 70.00 2.35 1.44 0.20 1.24 75.00 2.22 1.46 0.21 1.24 80.00 2.10 1.47 0.23 1.24 85.00 2.00 1.49 0.24 1.24 90.00 1.90 1.49 0.26 1.24 95.00 1.80 1.49 0.27 1.22 100.00 1.70 1.49 0.29 1.20 105.00 1.65 1.51 0.30 1.21 ----------------------------------------------------- �jd Zo S mot' THE REQUIRED POND SIZE = 1.244366 ACRE -FT - m ' THE RAINFALL DURATION FOR THE ABOVE POND STORAGE= 75 MINUTES r DETENTION POND HIGH WATER LINE Landings Bay PUD -Existing Detention Pond 54,205.0 = REQ. VOLUME CONTOUR AREA AVG AREA INTERVAL CUMULATIVE HIGH WATER Contour Storage (sq.fL) (sq.ft.) VOLUME (cu.ft.) VOL (cu.ft.) LINE (ft.) 25.8 1100.0 1,947.5 240.1 240.1 25.8 0.0 26.0 3,795.0 0.0 26.0 0.0 6,548.0 6,345.7 6,585.8 ' 27.0 9,301.0 0.0 27.0 0.2 10, 348.5 10, 330.8 16, 916.6 28.0 11,396.0 0.0 28.0 0.4 12,243.5 12,233.7 29,150.3 29.0 13,091.0 0.0 29.0 0.7 14,301.0 14,283.9 43,434.2 30.0 15,511.0 30.6 30.0 1.0 ' 16,694.5 14,678.8 58,113.1 30.9 17878.0 0.0 30.9 1.3 NOTES: 1. FOR THE FIRST CONTOUR VOLUME A CONIC SHAPE WAS ASSUMED VOL. = 113 (AREA ABOVE) (DIFFERENCE IN CONTOUR ELEV.) 2. FOR THE REMAIMDER OF THE VOLUMES BETWEEN CONTOURS (SECTION 9.2) VOL. = DEPTH/3 (A +(ABr.5 + B) FOR: Uniform Sides sec.(9.2) 3. HWL=(VOL.REQ: VOL.LOW CUML)-3/(AREA LOW+AREA HIGH+(low areafiigh area)A.5) 30.65 = HWL POND ORIFICE SIZING ORIGINAL DESIGN DATA 2.07 = Allowable Des. Release Rate(cfs) 25.00 = Tailwater Eleavtion 0.60 = Orifice Coefficient (Cd) 5.65 = Available Driving Head(ft) 25.81 = Flowline Elevation VERT. CIRCULAR PLATE 26.63 = Outlet Area(inches) 2.91 = Circular radius(inches) 5.40 = Actual Hydraulic Driving Head(ft) VERT. SQUARE PLATE 26.05 = Outlet Area(inches) 5.10 = Side for Sq. Opening(inches) 5.43 = Actual Hydraulic Driving Head(ft) HORZ. CIRCULAR PLATE 26.05 = Outlet Area(inches) 2.88 = Circular radius(inches) 5.65 = Actual Hydraulic Driving Head(ft) 1 NOTE: 1. VERT. PLATES WILL BE PLACED AT PIPE FLOWLINE -- i i 1 1 1 1 1 1 1 1 033 --- M N lk n �z �W G I0 a 151 00 DETENTION POND HIGH WATER LINE Landings Bay PUD -Existing Detention Pond 54,205.0 = REQ. VOLUME CONTOUR AREA AVG AREA INTERVAL CUMULATIVE HIGH WATER Contour Storage (sq.ft.) (sq.ft.) VOLUME (cu.ft.) VOL (cu.ft.) LINE (ft.) 25.8 100.0 25.8 3,352.5 417.9 417.9 0.0 26.0 6,605.0 0.0 26.0 0.0 7,747.5 7,719.3 8,137.2 27.0 8,890.0 0.0. 27.0. 0.2 9,966.5 9,947.1 18,084.2 28.0 11,043.0 0.0 28.0 0.4 12,243.0 12.223.3 30,307.E 29.0 13,443.0 0.0 29.0 0.7 14,718.0 14,699.6 45,007.1 30.0 15.993.0 30.5 30.0 1.0 17,328.5 15,234.0 60,241.1 30.9 18,664.0 0.0 30.9 1.4 NOTES: 1. FOR THE FIRST CONTOUR VOLUME A CONIC SHAPE WAS ASSUMED VOL. = 1/3 (AREA ABOVE) (DIFFERENCE IN CONTOUR ELEV.) 2. FOR THE REMAIMDER OF THE VOLUMES BETWEEN CONTOURS (SECTION 9.2) VOL. = DEPTH/3 (A +(AB)A.5 + B) FOR: Uniform Sides sec.(9.2) 3. HWL=(VOL.REQ.-VOL.LOW CUML)-3/(AREA LOW+AREA HIGH+(Iow area high area)A.5) 30.53 = HWL POND ORIFICE SIZING ORIGINAL DESIGN DATA 2.07 = Allowable Des. Release Rate(cfs) NOTE: 1. VERT. PLATES WILL BE PLACED 25.00 = Tailwater Eleaation AT PIPE FLOWLINE 0.60 = Orifice Coefficient (Cd) 5.53 = Avaliable Driving Head(ft) 25.81 = Flowline Elevation ' VERT. CIRCULAR PLATE 26.92 = Outlet Area(inches) 2.93 = Circular radius(inches) 5.29 = Actual Hydraulic Driving Head(ft) VERT. SQUARE PLATE 26.32 = Outlet Area(inches) 5.13 = Side for Sq. Opening(inches) 5.32 = Actual Hydraulic Driving Head(ft) HORZ. CIRCULAR PLATE 26.32 = Outlet Area(inches) ' 2.89 = Circular radius(inches) 5.53 = Actual Hydraulic Driving Head(ft) I [1 I 1 I I I I DESIGN OF PIPES, INLETS, CULVERTS DRAINAGE CRITERIA MANUAL STORM INLETS 0 cis _-Po_L�a.l►.X� ��PTN G-I . - 49.33 - 48.oZ �__L._31_� 0.8 0.7 0.6 L 0.5 > 0.4 0 ~a 0.3 w - 0 ? 0.2 c z 0 a 0.1 [41] us I IMMIMMIMEMAIMMI m—m-m-WAIMM1 lMMMMllMMNMIMMl 0101MEW'Amim mmiummmim 10001101001mmim ummommim"m I•LUW INTO INLET PEN 5O. FT. OF UFEN AREA (CF5/FT-) FIGURE 4-I. CAPACITY OF GRATED INLET IN SUMP 10-15-68 ---- - Denwr Regional Coteneit of 6ovemmnts I Deeter Foundry, Inc. P.O. Box 29708, Lincoln Nebraska 68529 2110-2125 Catch Basin Inlet Grates & Fram Heavy Duty 1. Grates for 2110-2125 have a depressed center bar. Catalog No. A B C E F G H Wt# Open Are. 2110 231/2x471/4 2 20x44 26x50 3 1'/ex211/2 '/a 555 484 2111 231/2x471/4 2 20x44 26x50 4 1'/ex21'/2 '/e 655 484 2115 331/2x51'/2 3 30x48 36x54 4 11/4x231/4 1 875 793 2115-A 331/2411%z 3 30x48 3644 4 1'/4x4"/i6 1 995 640 2120 391/2x391/2 3 36x36 42x42 4 1'/ax171/4 3/4 745 737 _-_2125 45'/2x45'/2 3 42x42 48x48 4 1'/ex201/4 3/4 990 957 2126 Catch Basin Inlet Grate & Frame Heavy Duty Total Wt. — 840# Open Area — 744 Sq. In. i 2135 Catch Basin Inlet Grate & Frame Heavy Duty Total Wt. — 640# Open Area — 443 Sq. In. 1. Can be furnished with 3' high frame. 2135-L Heavy Duty Total Wt. — 600# Open Area — 780 Sq. In. 1. Same as 2135 with L-style grate. �I-478/m"--------�1 --- I 1-7i� I I �1IV2„ L 44'/ie"—jj 50'/,6""----- ---- ..---239/16 ..- 4• ? ..26'/0- - iiG:iSi:i��7 .J 1 1 1 1 I - ------------------------------------------------------- UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ------------------------------------------------------------------------------ USER:Northern Engineering Services -Ft Collins Colorado ....................... 01 DATE 12-05-1998 AT TIME 16:50:29 *** PROJECT TITLE: COURTYARD COMMONS *** CURB OPENING INLET HYDRAULICS AND SIZING: ' INLET ID NUMBER: 4 INLET HYDRAULICS: IN A SUMP GIVEN INLET DESIGN INFORMATION: GIVEN CURB OPENING LENGTH (ft)= 2.00 HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 0.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 SUMP DEPTH (ft)= 0.25 Note: The sump depth is additional depth ' STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (%) = 0.60 STREET CROSS SLOPE (%) 2.00 ' STREET MANNING N 0.016 GUTTER DEPRESSION (inch)= 1.00 GUTTER WIDTH (ft) = 1.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 8.47 GUTTER FLOW DEPTH (ft) = 0.25 FLOW VELOCITY ON STREET (fps)= 1.87 FLOW CROSS SECTION AREA (sq ft)= 0.80 GRATE CLOGGING FACTOR (%)= 50.00 CURB OPENNING CLOGGING FACTOR(%)= 20.00 low depth. INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (cfs)= 4.59 BY FAA HEC-12 METHOD: DESIGN FLOW (Cfs)= 1.50 FLOW INTERCEPTED (CfS)= 1.50 CARRY-OVER FLOW (CfS)= 0.00 BY DENVER UDFCD METHOD: DESIGN FLOW (Cfs)= 1.50 FLOW INTERCEPTED (Cfs)= 1.50 ' CARRY-OVER FLOW (CfS)= 0.00 ------------------------------------------------------------------------------ ' UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD - -------------------------------------------------------------------- R:Northern Engineering Services -Ft Collins Colorado ....................... ON DATE 12-05-1998 AT TIME 16:30:36 *t PROJECT TITLE: COURTYARD COMMONS ' *** CURB OPENING INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 5STD ' INLET HYDRAULICS: IN A SUMP. .1 I I I I GIVEN INLET DESIGN INFORMATION: GIVEN CURB OPENING LENGTH (ft)= 12.50 HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 0.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 SUMP DEPTH (ft)= 0.09 Note: The sump depth is additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (°s) = 1.00 STREET CROSS SLOPE (o) = 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.00 GUTTER WIDTH (ft) = 1.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 15.91 GUTTER FLOW DEPTH (ft) = 0.40 FLOW VELOCITY ON STREET (fps)= 3.38 FLOW CROSS SECTION AREA (sq ft)= 2.61 GRATE CLOGGING FACTOR (o)= 50.00 CURB OPENNING CLOGGING FACTOR(s)= 12.50 INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (Cfs)= BY FAA HEC-12 METHOD: DESIGN FLOW FLOW INTERCEPTED CARRY-OVER FLOW BY DENVER UDFCD METHOD: DESIGN FLOW FLOW INTERCEPTED CARRY-OVER FLOW 12.76 F� - 34. -7Z (cfs)= 8.80 (cfs)= 8.80 (cfs)= 0.00 (cfs)= 8.80 (cfs)= 8.80 (cfs)= 0.00 I - ---------------------------------------------------- --- UDINLET: INLET HYDARULICS AND SIZING DEVELOPED BY Q - ,-DR�JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD --------- - ------------------------------------------------------------'- USER:Northern Engineering Services -Ft Collins Colorado ......................t� a' DATE 12-05-1998 AT TIME 16:32:57 J *** PROJECT TITLE: COURTYARD COMMONS ' *** CURB OPENING INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 5 INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: 31 ' GIVEN CURB OPENING LENGTH (ft)= 12.50 HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 0.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 SUMP DEPTH (ft)= 0.36 Note: The sump depth is additional depth to flow depth. STREET GEOMETRIES: ry �LaT�L�� i STREET LONGITUDINAL SLOPE (.) = 1.00 STREET CROSS SLOPE (%) = 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.00 GUTTER WIDTH (ft) = 1.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 21.63 GUTTER FLOW DEPTH (ft) = 0.52 FLOW VELOCITY ON STREET (fps)= 4.08 FLOW CROSS SECTION AREA (sq ft)= 4.75 GRATE CLOGGING FACTOR (.)= 50.00 CURB OPENNING CLOGGING FACTOR(.)= 12.50 ' INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (cfs)= 31.45 BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)= 19.50 FLOW INTERCEPTED (cfs)= 19.50 CARRY-OVER FLOW (cfS)= 0.00 BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)= 19.50 FLOW INTERCEPTED (cfs)= 19.50 ' CARRY-OVER FLOW (CfS)= 0.00 - UDINLET: -------INLET------HYDARULICS-----------AND----SIZING --------------------------- DEVELOPED BY -'----------DR.-JAMES-GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ----------------------------7--------------------------- USER:Northern Engineering Services -Ft Collins Colorado ....................... O� DATE 12-05-1998 AT TIME 16:56:44 * * * PROJECT TITLE: COURTYARD COMMONS �" sT �a>i Gl3?.S i iu L ET- I 1 *** CURB OPENING INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 10 INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: GIVEN CURB OPENING LENGTH (ft)= 15.00 HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 0.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 SUMP DEPTH (ft)= 0.00 Note: The sump depth is additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (t) = 0.80 STREET CROSS SLOPE ($) = 2.00 STREET MANNING N = 0.016 GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 12.72 GUTTER FLOW DEPTH (ft) = 0.38 FLOW VELOCITY ON STREET (fps)= 2.75 FLOW CROSS SECTION AREA (sq ft)= 1.74 ' GRATE CLOGGING FACTOR (0 = 50.00 CURB OPENNING CLOGGING FACTOR(%)= 10.00 INLET INTERCEPTION CAPACITY: IDEAL INTERCEPTION CAPACITY (cfs)= 10.00 BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)= 4.80 FLOW INTERCEPTED (cfs)= 4.80 ' CARRY-OVER FLOW (CfS)= 0.00 BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)= 4.80 FLOW INTERCEPTED (cfs)= 4.80 CARRY-OVER FLOW (cfs)= 0.00 ------------------------------------=---------- r UDINLET:-INLET-HYDARULICS-AND-SIZING---- DEVELOPED BY DR. JAMES GUO, CIVIL ENG DEPT. U OF COLORADO AT DENVER -,-----------SUPPORTED BY METRO DENVER CITIES/COUNTIES AND UD&FCD ---------------------------------------------------------------- USER:Northern Engineering'Services-Ft Collins Colorado ....................... C� DATE 12-05-1998 AT TIME 16:59:27 * * * PROJECT TITLE: COURTYARD COMMONS C��p$ 1�_I TL *** .1 CURB OPENING INLET HYDRAULICS AND SIZING: INLET ID NUMBER: 10 INLET HYDRAULICS: IN A SUMP. GIVEN INLET DESIGN INFORMATION: GIVEN CURB OPENING LENGTH (ft)= 15.00 ' HEIGHT OF CURB OPENING (in)= 6.00 INCLINED THROAT ANGLE (degree)= 0.00 LATERAL WIDTH OF DEPRESSION (ft)= 2.00 ' SUMP DEPTH (ft)= 0.00 Note: The sump depth is additional depth to flow depth. STREET GEOMETRIES: STREET LONGITUDINAL SLOPE (t) = 0.80 ' STREET CROSS SLOPE STREET MANNING N ($) = = 2.00 0.016 GUTTER DEPRESSION (inch)= 1.50 GUTTER WIDTH (ft) = 2.00 STREET FLOW HYDRAULICS: WATER SPREAD ON STREET (ft) = 17.69 GUTTER FLOW DEPTH (ft) = 0.48 FLOW VELOCITY ON STREET (fps)= 3.28 FLOW CROSS SECTION AREA (sq ft)= 3.25 ' GRATE CLOGGING FACTOR (g)= 50.00 CURB OPENNING CLOGGING FACTOR(o)= 10.00 INLET INTERCEPTION CAPACITY: ' IDEAL INTERCEPTION CAPACITY (cfs)= 14.17 BY FAA HEC-12 METHOD: DESIGN FLOW (cfs)= 10.70 FLOW INTERCEPTED (cfs)= 10.70 CARRY-OVER FLOW (CfS)= 0.00 BY DENVER UDFCD METHOD: DESIGN FLOW (cfs)= 10.70 FLOW INTERCEPTED (cfs)= 10.70 CARRY-OVER FLOW (cfs)= 0.00 I i r 1 i 1 1 1 1 1 1 i ' COURTYARD COMMONS STORM SEWER SYSTEM 1 12 , 20 , 3 2 , 1 , .8 , 500 300 .2 , Y 2 , 100 4.9 , 3.8 2.7 2.2 1.8 , 1.4 .89 11 1, 30.5 0 1, 12 0 0 0 ' 34.7 , 0 2 .2 , 0 0 0 0 0 2, 31 , 12 1, 23 0 0 0 34.7 , 0, 2 .2 , 0 0 0 0 0 ' 3, 31 , 23 1, 38 0 0 0 34.7 , 0 2 .2 0 0 0 0 0 8, 36.5 38 1 89 0 0 0 34.7 9, , 0 2 .2 34.72 89 , 1 0 0 0 910 0 0 0 0 0 34.7 , 0 2, .2 0 0 0 0 0 10 , 36.15 , 910 1 1011 , 0 , 0 , 0 15.2 , 0 2, .2 0 0, 0, 0, 0 ' 11 , 42.6 1011 1 1112 , 0 , 0 , 0 15.2 , 0 2, .2 0 0, 0 0 0 12 , 42.12 , 1112 1 1213 0 0 0 15.2 , 0 2, .2 0 0 0 0 0 ' 13 , 52 1213 , 1 1314 0 0 0 10.2 , 0 2, .2 0 0 0 0 0 14 , 48.02 , 1314 1 1415 0 0 0 ' 10.2 , 0, 2, .2 0 0 0 0 0 15 , 48.02 , 1415 0 0 0 0 0 10.2 , 0 2, .2 0 0 0 0 0 10 12 86.1 .98 29.89 .013 1 0 1 36 0 23 75 , .48 , 30.25 , .013 , .06 0 1 36 0 38 67.76 2.51 31.55 .013 1 , 0 , 1 , 30 , 0 89 61.04 2.48 33.15 .013 .16 0 1 , 30 , 0 910 25 , 2.5 , 33.78 , .013 , .25 , 0 1 21 , 0 1011 50 , 6.5 , 37.13 , .013 , .45 , 0 1 21 , 0 1112 45.06 , 6.5 , 40.16 , .013 , .45 0 1 , 21 0 1213 60 , 7.03 , 44.38 .013 .45 0 1 18 0 ' 1314 126.91 .8 , 45.5 .013 .45 0 1 18 0 1415 .1 , .8 45.5 , .013 , 1.25 , 0 1 18 , 0 18 0 '1 1314 126.91 .8 , 45.5 , r ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ STORM SEWER SYSTEM DESIGN USING UDSEWER MODEL Developed by Dr. James Guo, Civil Eng. Dept, U. of Colorado at Denver Metro Denver Cities/Counties & UDFCD Pool Fund Study ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ USER:NORTHERN ENG SERVICES INC-FT COLLINS COLORADO ........................... ON DATA 04-22-1999 AT TIME 09:24:54 VERSION=03-26-1994 *** PROJECT TITLE :COURTYARD COMMONS *** SUMMARY OF HYDRAULICS AT MANHOLES i ------------------------------------------------------------------------------- MANHOLE CNTRBTING RAINFALL RAINFALL DESIGN GROUND WATER COMMENTS ID NUMBER AREA * C DURATION INTENSITY PEAK FLOW ELEVATION ELEVATION MINUTES INCH/HR CFS FEET FEET ------------------------------------------------------------------------------- 1.00 0.00 0.00 0.00 34.70 30.50 30.57 NO 2.00 7.08 5.91 4.90 34.70 31.00 30.43 OK 3.00 7.08 5.73 4.90 34.70 31.00 30.65 OK 8.00 7.08 5.65 4.90 34.70 36.50 31.36 OK 9.00 7.08 5.57 4.90 34.70 34.72 32.65 OK 10.00 3.10 5.54 4.90 15.20 36.15 33.63 OK 11.00 3.10 5.48 4.90 15.20 42.60 36.82 OK 12.00 3.10 5.44 4.90 15.20 42.12 39.85 OK 13.00 2.08 5.37 4.90 10.20 52.00 44.11 OK 14.00 2.08 5.00 4.90 10.20 48.02 45.69 OK 15.00 2.08 5.00 4.90 10.20 48.02 46.33 OK OK MEANS WATER ELEVATION IS LOWER THAN GROUND ELEVATION *** SUMMARY OF SEWER HYDRAULICS NOTE: THE GIVEN FLOW DEPTH -TO -SEWER SIZE RATIO= .8 ------------------------------------------------------------------------------- SEWER MANHOLE NUMBER SEWER REQUIRED SUGGESTED EXISTING ID NUMBER UPSTREAM DNSTREAM SHAPE DIA(RISE) DIA(RISE) DIA(RISE) WIDTH ID NO. ID NO. (IN) (FT) (IN) (FT) (IN) (FT) (FT) ------------------------------------------------------------------------------- 12.00 2.00 1.00 ROUND 32.34 33.00 36.00 0.00 23.00 3.00 2.00 ROUND 32.34 33.00 36.00 0.00 38.00 8.00 3.00 ROUND 23.71 24.00 30.00 0.00 89.00 9.00 8.00 ROUND 23.77 24.00 30.00 0.00 910.00 10.00 9.00 ROUND 17.41 18.00 21.00 0.00 1011.00 11.00 10.00 ROUND 14.56 15.00 21.00 0.00 1112.00 12.00 11.00 ROUND 14.56 15.00 21.00 0.00 1213.00 13.00 12.00 ROUND 12.35 15.00 18.00 0.00 1314.00 14.00 13.00 ROUND 18.57 21.00 18.00 0.00 1415.00 15.00 14.00 ROUND 18.57 21.00 18.00 0.00 DIMENSION UNITS FOR ROUND AND ARCH SEWER ARE IN INCHES DIMENSION UNITS FOR BOX SEWER ARE IN FEET REQUIRED DIAMETER WAS DETERMINED BY SEWER HYDRAULIC CAPACITY. SUGGESTED DIAMETER WAS DETERMINED BY COMMERCIALLY AVAILABLE SIZE. FOR A NEW SEWER, FLOW WAS ANALYZED BY THE SUGGESTED SEWER SIZE; OTHERWISE, EXISTING SIZE WAS USED I i I V 1 I 1 1] I I ------------------------------------------------------------------------------- SEWER DESIGN FLOW NORMAL NORMAL CRITIC CRITIC FULL FROUDE COMMENT ID FLOW Q FULL Q DEPTH VLCITY DEPTH VLCITY VLCITY NO. NUMBER -- --------- CFS-----CFS --------------------------------- FEET FPS FEET FPS 12.0 34.7 46.3 1.94 7.19 1.91 -----FPS 7.31 --------------- 4.91 0.98 V-OK 23.0 34.7 46.3 1.94 7.19 1.91 7.31 4.91 0.98 V-OK 38.0 34.7 65.2 1.30 13.49 2.00 8.25 7.07 2.34 V-OK 89.0 34.7 64.8 1.30 13.43 2.00 8.25 7.07 2.33 V-OK 910.0 15.2 25.1 0.98 10.94 1.44 7.19 6.32 2.16 V-OK 1011.0 15.2 40.5 0.74 15.63 1.44 7.19 6.32 3.67 V-OK 1112.0 15.2 40.5 0.74 15.63 1.44 7.19 6.32 3.67 V-OK 1213.0 10.2 27.9 0.63 14.56 1.23 6.60 5.77 3.73 V-OK 1314.0 10.2 9.4 1.50 5.77 1.23 6.60 5.77 0.00 V-OK 1415.0 10.2 9.4 1.50 5.77 1.23 6.60 5.77 0.00 V-OK FROUDE NUMBER=O INDICATES THAT A PRESSURED FLOW OCCURS SEWER SLOPE INVERT ELEVATION BURIED DEPTH COMMENTS ID NUMBER UPSTREAM DNSTREAM UPSTREAM DNSTREAM ---------------------------------------------------------------------- % (FT) (FT) (FT) (FT) 12.00 0.48 26.89 26.48 1.11 1.02 OK 23.00 0.48 27.25 26.89 0.75 1.11 NO 38.00 2.51 29.05 27.35 4.95 1.15 OK 89.00 2.48 30.65 29.14 1.57 4.86 OK 910.00 2.50 32.03 31.40 2.37 1.57 OK 1011.00 6.50 35.38 32.13 5.47 2.27 OK 1112.00 6.50 38.41 35.48 1.96 5.37 OK 1213.00 7.03 42.88 38.66 7.62 1.96 OK 1314.00 0.80 44.00 42.98 2.52 7.52 OK 1415.00 0.80 44.00 44.00 2.52 2.52 OK OK MEANS BURIED DEPTH IS GREATER THAN REQUIRED SOIL COVER OF 1 FEET *** SUMMARY OF HYDRAULIC GRADIENT LINE ALONG SEWERS ------------------------------ SEWER SEWER SURCHARGED ID NUMBER LENGTH LENGTH ---------------------- FEET FEET 12.00 86.10 86.10 23.00 75.00 75.00 38.00 67.76 46.88 89.00 61.04 0.00 910.00 25.00 0.00 1011.00 50.00 0.00 1112.00 45.06 0.00 1213.00 60.00 0.00 1314.00 126.91 126.91 1415.00 0.10 0.10 ------------------------------------------------ CROWN ELEVATION WATER ELEVATION FLOW UPSTREAM DNSTREAM UPSTREAM DNSTREAM CONDITION FEET ------------------------------------------------ FEET FEET FEET 29.89 29.48 30.43 30.57 PRSS'ED 30.25 29.89 30.65 30.43 PRSS'ED 31.55 29.85 31.36 30.65 JUMP 33.15 31.64 32.65 31.36 JUMP 33.78 33.15 33.63 32.65 JUMP 37.13 33.88 36.82 33.63 JUMP 40.16 37.23 39.85 36.82 JUMP 44.38 40.16 44.11 39.85 JUMP 45.50 44.48 45.69 44.11 PRSS'ED 45.50 45.50 46.33 45.69 PRSS'ED PRSS'ED=PRESSURED FLOW; JUMP=POSSIBLE HYDRAULIC JUMP; SUBCR=SUBCRITICAL FLOW 1 11 I*** SUMMARY OF ENERGY GRADIENT LINE ALONG SEWERS --------------------------------------------------------------------------- UPST MANHOLE SEWER JUNCTURE LOSSES DOWNST MANHOLE SEWER MANHOLE ENERGY FACTION BEND BEND LATERAL LATERAL MANHOLE ENERGY ID NO ID NO. ELEV FT FT K COEF LOSS FT K COEF LOSS FT ID FT ------------------------------------------------------------------------- 12.0 2.00 30.80 0.23 1.00 0.00 0.00 0.00 1.00 30.57 23.0 3.00 31.03 0.20 0.06 0.02 0.00 0.00 2.00 30.80 38.0 8.00 32.14 0.33 1.00 0.78 0.00 0.00 3.00 31.03 89.0 910.0 9.00 10.00 33.70 34.25 1.45 0.16 0.39 0.25 0.12 0.00 0.00 0.16 0.00 0.00 8.00 9.00 32.14 33.70 1011.0 11.00 37.62 3.10 0.45 0.28 0.00 0.00 10.00 34.25 1112.0 12.00 40.65 2.75 0.45 0.28 0.00 0.00 11.00 37.62 1213.0 13.00 44.78 3.90 0.45 0.23 0.00 0.00 12.00 40.65 1314.0 14.00 46.20 1.19 0.45 0.23 0.00 0.00 13.00 44.78 1415.0 15.00 46.85 0.00 1.25 0.65 0.00 0.00 14.00 46.20 BEND LOSS =BEND K* FLOWING FULL VHEAD IN SEWER. LATERAL LOSS= OUTFLOW FULL VHEAD-JCT LOSS K*INFLOW FULL VHEAD FRICTION LOSS=O MEANS IT IS NEGLIGIBLE OR POSSIBLE ERROR DUE TO JUMP. FRICTION LOSS INCLUDES SEWER INVERT DROP AT MANHOLE NOTICE: VHEAD DENOTES THE VELOCITY HEAD OF FULL FLOW CONDITION. A MINIMUM JUNCTION LOSS OF 0.05 FT WOULD BE INTRODUCED UNLESS LATERAL K=O. FRICTION LOSS WAS ESTIMATED BY BACKWATER CURVE COMPUTATIONS. I is II I DESIGN OF SWALES, CHANNELS, RIPRAP i i i I No Text DRAINAGE CRITERIA MANUAL RIPRAP To n 4C a 0 ENEENEEMOM MENEM MEMO M EN :. pol rA A Mill ■■ ./E/ ppsPlAlJ .aA ENEWEEN M—E 00 .2 .4 Y t�D .6 .8 1.0 Use Do instead of D whenever flow is supercritical in the barrel. **Use Type L for a distance of 3D downstream. z.s FIGURE 5-7.' RIPRAP EROSION PROTECTION AT CIRCULAR CONDUIT OUTLET. ,%Z 11-15-82 URBAN DRAINAGES FLOOD CONTROL DISTRICT DRAINAGE CRITERIA MANUAL 9 = Expansion Angle vMEN ENE m no I��immmmml .1 .2 .3 A .5 .6 .7 .8 TAILWATER DEPTH/ CONDUIT HEIGHT, Yt/D RIPRAP FIGURE 5-9. EXPANSION FACTOR FOR CIRCULAR CONDUITS >>-15-82 URBAN DRAINAGE 9 FLOOD CONTROL DISTRICT i EROSION CONTROL 0 I I I fJ October 21, 1996 Mr. Jay Barber City of Fort Collins Utility Services Stormwater 235 Mathews Fort Collins, Colorado 80522 RE: Courtyard Commons Erosion Control Security Deposit Estimate Dear Jay, The following letter is intended to serve as a basis for the Erosion Control Security Deposit for Courtyard Commons. This estimate is based on the Final Utility. plans as they have been resubmitted to the City for review on December 9, 1998 An itemized listing of the erosion control measures incorporated into this design include the following: Temporary Seed & Mulch Gravel filters (located around all curb and area inlets) Silt fence (Located around the north, west, and easterly perimeters of the site) Temporary truck wash pad A breakdown of anticipated costs for these improvements include: Temporary Seed & Mulch 1.9 ac @ $800.00/ac = $1520.00 Gravel filters 5 ea @ $250.00/ea = $1250.00 Silt Fence 18251f @ $ 2.00/lf = $3650.00 Temporary truck wash pad 1 ea @ $750.00/ea = $ 750.00 Total $7170.00 150% $10,755.00 An alternate look at this obligation: Total disturbed area (total site area, although it is not intended to disturbed the entire site at within the scope of this project) - 5.07 acres 5.07 acres @ $500.00 * 150%= $3802.00 Based on the above figures, and the City policy to use the higher estimate, the Erosion Control Security Deposit obligation of the developer for Courtyard Commons would be $10,755.00 Please call if you have any questions regarding these figures 1 Sincerely, Roger Curtiss P.E. - Northern Engineering Services, Inc. cc: Jon Prouty - Lagunitas i I r i i RAINFALL PERFORMANCE STANDARD EVALUATION PROJECT: �t�v1ZTP�IJ STANDARD FORM A COMPLETED BY: DATE: 6 •� - 9� DEVELOPED SUBBA§IN ERODIBILITY ZONE Asb (ac) Lsb (ft) Ssb M Lb (feet) Sb ($) PS ($) ME✓ -- - ----_—._-_-. _.VY1uC.T_]_ _�.Q.l1'1 I_ � � .41..r_-- _ -_----- _..____-.- MARCH 1991 B•14 DESIGN CRITERIA EFFECTIVENESS CALCULATIONS STANDARD FORM B COMPLETED BY: DATE: Erosion control' C-Factor P-Factor Method Value Value Comment MAJOR 'SF SUB I AREA BASINI (it ) BASIN (JCALCULATIONS K10P,7744 - ---------- -- - - --- ---- -�=�► . � ► �o. a�� ems. � -o. o�- -- - 119r-------- MARCH 1991 B-15 DESIGN CRITERIA I I I t 11 I I i CONSTRUCTION SEQUENCE SEQUENCE FOR 1999 COMPLETED BY: BUD DATE: DECEMBER, 1998 Y9K 1999 MONTH JUN I JLY AUG SEP OCT NOV DEC JAN FEB MAR OVERLOT GRADING: WIND EROSION CONTROL: Soil Roughening Perimeter Barrier Additional Barriers Vegetative Methods Soil Sealant Other RAINFALL EROSION CONTROL STRUCTURAL: Sediment Trap/Basin Inlet Filters Straw Barriers Silt Fence Barriers Sand Bags Bare Soir Preparation Contour Furrows Terracing Paving RipRap Outlet Control VEGETATIVE: Permanent Seed Plantin Mulching/Sealant Temporary Seed Planting Sod Ins allation Netting Mats/Blankets Other i i 1 I Li I 1 I r [1 11 I CHARTS, GRAPHS, TABLES i DRAINAGE CRITERIA MANUAL 5C 3C 1— 20 z W U Ix W a 10 z W a O 5 In W oyc 3 O Ca 2 W 1 RUNOFF .A 1 2 3 5 10 20 VELOCITY IN FEET PER SECOND FIGURE 3-2. ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. *MOST FREQUENTLY OCCURRING "UNDEVELOPED" LAND SURFACES IN THE DENVER REGION. REFERENCE: "Urban Hydrology For Small Watersheds" Technical Release No. 55, USDA, SCS Jan. 1975. 5-1-84 URBAN DRAINAGE d FLOOD CONTROL DISTRICT I INTERPOLATED VALUES FOR 100 YEAR INTENSITIES Tc Value 6j,/64M, 5.00 9.0 5.20 9.0 5.20 8.9 5.30 8.9 5.40 8.9 5.50 8.8 5.60 6.8 5.70 8.7. 5.80 8.7 5.90 8.7 6.00 8.6 6.10 8.6 6.20 8.6 6.30 8.5 6.40 8.5 6.50 8.5 6.60 8.4 6.70 8.4 6.80 8.4 •6.90 8.3 7.00 8.3 7.10 8.2 7.20 8.2 7.30 8.2 7.40 S.1 7.50 8.1 7.60 8.1 7.70 8.0 7.80 8.0 7.90 8.0 8.00 7.9 8.10 7.9 8.20 7.6 8.30 7.8 8.40 7.8 8.50 7.7 8.60 7.7 8.70 7.7 8.80 7.6 8.90 7.6 9.00 7.6 9.10 7.5 9.20 7.5 9.30 7.5 9.40 7.4 9.50 7.4 9.60 7.3 9.70 7.3 9.80 7.3 9.90 7.2 10.00 7.2 MEMEMEMMIXEMENUMEMIMEM mmmummummmmummmmommo mmosommsommmommmmumm iiiiiiiiiiiiiiiiiiii .mmmmm C■■.■■■■..■■wwwwommommm■■■■■■ .................... on so nn� n■■u n.■.■ u.■■■ ■■■■■ ■n■.■ WAIMECUMENJAKENNEEMNEW on MIN ARTERIAL W/ 6" VERT - Minor Storm ev Worksheet for Irregular Channel Project Description Project File c:\drainageXhaestad\fmvvX&eet c.fm2 Worksheet MINOR ARTERIAL W/ 6" VERTICAL Flow Element Irregular Channel Method Manning's Formula Solve For Discharge Input Data Channel Slope 0.004000 ft/ft Water Surface Elevation 99.85 ft Elevation range: 99.35 ft to 100.50 ft. Station (ft) Elevation (ft) Start Station End Station Roughness 0.00 100.50 0.00 26.50 0.016 0.00 100.00 26.50 36.00 0.035 ' 24.00 99.52 36.00 42.00 0.016 26.00 99.35 42.00 59.00 0.035 26.00 99.85 ' 26.50 99.85 36.00 100.04 42.00 100.16 I59.00 100.50 Results Wtd. Mannings Coefficient 0.016 Discharge 6.82 cfs ' Flow Area 3.55 ftz Wetted Perimeter 19.01 ft_�-�� Top Width 18.50 ft Height Critical Depth 0.50 99.81 ft ft Z/ _ 3 40)__ Critical Slope 0.006940 ft/ftT h / Velocity Velocity Head 1.92 0.06 ft/s ft Z� 3 • ss � Specific Energy 99.91 ft Froude Number Flow is subcritical. 0.77 b.ol 0� -- _k IZ J ETC 2� 12/05/98 FlowMaster v5.13 02:35:38 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 1 J MIN ARTERIAL W/ 6" VERT - 100 Year Worksheet for Irregular Channel Project Description Project File c:\drainage\haestad\fmw\street c.fm2 Worksheet MINOR ARTERIAL W/ 6" VERTICAL Flow Element Irregular Channel Method Manning's Formula Solve For Discharge ' Input Data Channel Slope 0.004000 ft/ft Water Surface Elevation 100.16 ft Elevation range: 99,35 ft to 100.50 ft. Station (ft) Elevation (ft) Start Station End Station Roughness 0.00 100.50 0.00 26.50 0.016 0.00 100.00 26.50 36.00 0.035 ' 24.00 99.52 36.00 42.00 0.016 26.00 99.35 42.00 59.00 0.035 26.00 99.85 26.50 99.85 36.00 100.04 42.00 100.16 ' 59.00 100.50 ' Results z/3 Wtd. Mannings Coefficient 0.021 ► 3.6 I 4�� Discharge 28.50 cfs , Flow Area 13.61 ft' -x--�� ' Wetted Perimeter 42.68 ft Top Width 42.00 ft Height 0.81 ft Critical Depth 100.06 ft Critical Slope 0.010773 ft/ft --- -------------------- Velocity 2.09 ft/s 1 Velocity Head 0.07 ft --- _ - - - -- --- Specific Energy 100.23 ft - -- ----------- Froude Number 0.65 Flow is subcritical. 12/051s8 02:35:08 PM FlowMaster v5.13 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 1 ' ^ N (D ...i b �--� � le O le � r Vl N �--� 00 m �o V) w � N oopp M at r O O �? O N M vl (71 N %n r w CN O — . O O C• C+ r- t, �o V en N en W) ^ N N N eV N N M en en en en M M M en M M M M M M M v N %C %O as r N %0 r I-t r �O C` fV �O �o N O qe le h O, le to w O\ r d• 7 r • M N �O 00 O — ... � N O V1 WVl O ^ O C� V) WO, 1, � OA N M M N O W Vl O r- C eV � v1 O r O N 'a vi � Vi tei Iti e+i M _- C 0: r b h Ni vi r Va •r N N M M M M Vl Vl V1 V1 Vl V) Vf V1 Vf V) V) Vl d• « N N N N N N N N N N N N N N N N N N N N N N N N N N N N N rn A Vi V1 V1 V1 V1 h In h h h V1 In v1 Vt Vt V1 h V1 h V1 Vl h Vi h h h Wi h V1 O x Ol O` C\ ON O\ O, Q, Q, O` Q\ O\ as as as ON as ON O` ON O. O. O\ O` D` D\ ON 011 C\ •U Li M M M M M M M M M M M en M M M M M M e6 e+7 M C+; M M M M M M M U cyi w ' �o OA M M M N '+ O r N r+ ON o0 O N '(, V , .j > ^y ^ N M M 7 4 4 Vi Vi 146 146 16 u tU 3 W o U _ W t0 5 N Vl w�+ wN %n V1 po 0` O' V• N M o O 7 m wqe O V1 N n Vf OA p •� ii 3 �+ �ON%ON r—�o%a 4n as 7�M.+�ooMNoO M.••�oo h(71 Ci G3 ^ en `7 �o r r 00 06 C� O N N N en C+; M en M N eV N N a U „ C7 F p Q N N N N N N N N N N N N N N N N N N N N N N N N N N fV N N N U � o W � t�t�t�rrrrrrrrc�rrrc�rrt�t�c�t�t�rrrrrr v $ o rrrc�c�c�c�0c.c�c ooc,oc(Dc-rcrrrrc,c,c, c, 0 0 cc 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 v� s z g w N N 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 CY w°I y 04 m z � •z o 0 0 0 0 0 0 0 0 0 0 6 0 0 0 6 60 c o 6 6 666 o c o 6 � 04w ' 0tn 00QCA O Cn O r, v�O en QN Or- Nkn O r- v1 O r, W) RR v'� 1� 00 O N h to tC14o 0 r v to 0 to v N an W) 0 W) dD 06 6 0 0 0 N N N N M M M M 4 a 7 a vi V7 h NY 1. e I ARTERIAL W/ 6" VERTICAL - Minor Stone Worksheet for Irregular Channel Project Description Project File c:\drainage\haestad\fmw\street c.fm2 Worksheet ARTERIAL W/ 6" VERTICAL C&G ' Flow Element Irregular Channel Method Manning's Formula ' Solve For Discharge ' Input Data Channel Slope 0.004000 ft/ft Water Surface Elevation 99.05 ft Elevation range: 911.55 ft to 100,50 ft. Station (ft) Elevation (ft) Start Station End Station 0.00 100.50 0.00 9.00 0.00 100.00 9.00 42.00 ' 9.00 99.82 42.00 51.50 9.50 99.82 51.50 57.50 9.50 99.32 39.50 98.72 41.50 98.55 41.50 99.05 42.00 99.05 51.50 99.24 57.50 99.36 Results 11 I Wtd. Mannings Coefficient 0.016 Discharge 6.82 cfs t Roughness 0.035 0.016 0.035 0.016 Z/3 'r- VZ Flow Area 3.55 ft2 Wetted Perimeter 19.01 ft Top Width 18.50 ft Height 0.50 ft •4 3'ss ) 3 Critical Depth 99.01 ft_.. _-_ �•OIb3.S51�•01 / Critical Slope 0.006940 ft/ft Velocity 1.92 ft/s Velocity Head 0.06 ft Specific Energy 99.11 ft Froude Number 0.77 Flow is subcritical. 12/05/98 02:37:42 PM FlowMaster v5.13 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 I ARTERIAL W/ 6" VERTICAL - Major Storm Worksheet for Irregular Channel Project Description Project File c:\drainagekhaestad\fmw\street c.fm2 Worksheet ARTERIAL W/ 6" VERTICAL C&G Flow Element Irregular Channel Method Manning's Formula Solve For Discharge ' Input Data Channel Slope 0.004000 ft/ft Water Surface Elevation 99.36 ft Elevation range: 98.55 ft to 100,50 ft. ' Station (ft) Elevation (ft) Start Station 0.00 100.50 0.00 0.00 100.00 9.00 ' 9.00 99.82 42.00 9.50 99.82 51.50 9.50 99.32 ' 39.50 98.72 41.50 98.55 41.50 99.05 42.00 99.05 51.50 99.24 57.50 99.36 1 Results Wtd. Mannings Coefficient 0.020 Discharge 28.88 cfs Flow Area 14.21 ftz Wetted Perimeter 48.56 ft ' Top Width 48.00 ft Height 0.81 ft Critical Depth 99.27 ft ' Critical Slope 0.010452 ft(ft Velocity 2.03 ft/s Velocity Head Specific Energy 0.06 99.42 ft ft Froude Number 0.66 Flow is subcritical. ' End Station 9.00 42.00 51.50 57.50 12/05/98 02:38:13 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Roughness 0.035 0.016 0.035 0.016 V4s.�� FlowMaster v5.13 Page 1 of 1 CI 1 [] 1 O 1 1 1 1 It^ M O\ R O\ N M^ h^ m qe N m h v O M N%n^ O1 V1 w O^ It h O O^ M v%0 D` N le n w O\ O O O O O a\ O+ h h Vl d; M M N M v yM� V M M M M M M P7 fn M M M 186 00 N O\ v V1 O N M D\ O V1 %n V1 N^ m 0% b h�--t^ v *� V1 N h O b V) Q\ h M 00 ^ M M N �O �D N �O lq! ON ^ O 00 It t- 00 �O M h Q\ O O 00 �O It N 00 ^ M Vl h ^ Vl O% N v V1 h 00 (-z h b Vl Vl f-i N O O\ 00 �O Vl h O\ ^ N N M M M M'-t v v Vf Vl N'1 N'1 V1 Vl Vl Vf h V'1 V'1 Vl Vl v v Q v v v a V A a.i W o En M M M M M M M M M M M M M M M M M M M M M M M M M M M M M O 0 X kn tn kn tO �W�p) ��p Vl Vl %n �Vp1 �Vpl Vl Mtn �Vp1 V) tn � Vl �Ll1 tn � ke;� tr;� kl�� 41�� � vi wi N N N N N N N N N N N N N N N N N N N N N N N N N N N N N vasavv'ql: qd:v'ivvvvtqttvvvatgvvvvvvv �C h -e 00 00 h � O O+ N 7 M Ch �--� ^ CA w7 O+ ^ O\ O` 7 O, N M M N 00 ItN 00 1* NO 00 N V1 O` N Vl �D 00 O\ O+ O` 00 00 h V) V1 M N ^ O O% O N F7 > vz 5 V) w0o N V, V pp O\ p N M O It w le O 4n N V V O\ o «+ v ON �O N h ^ �O �O to 7 ^ �O O� N - M ^ ON 00 M N w M �-+ 00 V) O, �V y M y %O h h 00 00 O\ O^ N N N M m M M en N^^ N^^^ 0 C. 0ul W av � N N N N N N N N N N N N N N N N N N N N N N N N N N N N N C X h h r h h h h h h h h h h h h h h h h h h h h h h h h h 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o o 0 0 WD D\ 0 D a D O` O\ T O+ O\ D\ CN O\ as as Os a (2\ O\ O, O` (71 ON O+ Os ON D ON b�O b�O b�D �O �O %0 %Q b %Z �O �O b b NO NO b NO �O b NO b�O b N N N N N N N N N N N N N N N N N N N fV N N N N N N N fV N (Yi V zz q ������������r°������V)L�<�4���< 00000000000000000000000000000 aw �O Q O O� 8 V 1 O In 8 to O to O to O to g kn O N O %n O V) kn h 00 N Vl l- N V1 h C NW) [- N wn l- O NW) h C kn N N N M en M e;.qq: 44 4 vt V) v1 Vf �O �O h o 1 ,If 3a_z 4a�w ••_ INSREMOVE [� B '� I _4 —'--� `� o \-- 4Ll CURB �T—`t-- >�f 0 ru S & Crib .?^-'^..cam„- l SHT Iz .il �pA►i!C_WA,• - _ _ r----.-t;_ IF 0 No +. .. ;,� '•, -.-••..-- -.,// INSi, CIxJ� B K job _giIi By - - ' -yo- r a;q'rt IENN , I x. I •� \. .. jjff vV nx-MCA•WiT MI NLfl IB.A i) . to )r IJ A y I I W 4r' I I I yy I -------------- LB. G.I ' III CURB = PER I LARIMER NO. 2 CANAL COMPANY ST 1 CALL 111IL1tt NOTFICATON CENTER OF COLORADO H 1-800-922-=7 OR 534-6700 IN WAND CALL 2 BUSINESS PAYS IN AR E BEFORE YOU 00 WAGE OR EXCAVATE I, FOR THE BANKING OF UNDERGROUND I' MEMBER UTEITES. TOYS R US --- - - --... / r I'sD /Y GSf.. T�WwM% � 1T —fGDAF fO{!D' ` b i 1p Y� !IvD" KZB vfI"i4 J � �g Mtn L15 ; LEGEND: ,"xx..; — — — — H1 RJsrWG sroxu xMER JAM..-C'y,/�a7N^Sp ., /�.. EXISTING sigW 9EY.£R WLEi BE i4q PROPOSED SNRM sCWLA r \\yF' O/�" IT--PRGPoSED STORM MEMBER INLET _._ W ETSTING CONTOUR '°',5_f3AV 444�,4i�. -.':, may,' O W20 R J • 43' `• ; %', ' sP• !R,•w/.. All '�.; — zD— PROPOSED WNioua ✓')l 9FA / 44 - F�`.G.F.,/• ® uurw �5 sw,uE s[ciwH PN \ ' _1 RIPIUP OVBFi NM2CTEH V 4 •• \ %T `s --``�� SEE SENT. BHT G BS Fir- \ ! p TO�. .0 .. SO- BID FAA ..s+.-' �• K ' • .-`O ( TER ) , FtlT ]0 R. /��O�s '`� `�` �•• CITY OF FORT COLLINS STANDARD FI GENERAL GRADING AND EROSION CONTROL NOTES: T f iM `. THE Cn OF FORT COLLINS STORMwATER UTILITY EROSION CONNOTE INSPECTOR MUST BE NOTICE� Ai LFISr 24 HOURS PRIOR TO ANY LCMS'IRUCTOX ON THIS SITE COURTYA HNC ''A' / ,/' •Ji/' �• z.'.4 REODREO PERIMETER sLT FENCING sWLLL BE wsNN1ED MOR TO MY CARD PSNRBING MIY (SIOCKPLxC STRPPINc GRADING. RC) ALL OTHERj• REGVIREp EROSION CONTROL MEASURES SHALL BE NSFI AT THE APPROXIMATE TIME IN THE STRUCTKKI SEQUENCE AS BENCIFTED BY THE IFPAGMED PROJECT ` ] =R' Cal •, wIwwn4 200 UI.. ' < MORETTCONSTRUCTION PVHs EIMSCpJRaQ AND KIN BEFORE 5oI CyINe W 0525 L, pp J' �• 1 - + J. PIE CMURBWCE VEGETATION SHALL BE PROJEC OD NBA RENNIN WXONREVER PoSSBLE RENT! OR DISNROWLE OF EXISTING YEGRAMAV SHALL BE DMDW M (NJ) us-NODN- (AL / /• i Po. (STIR) zE6 51]5 THE IAFA REQUIRED FOR M EONif CONSTRUCTION CPW.TOXS T THE $XORRP PRLCD PERIOD CF TIME '\ : .J J , i� J� i:f ♦. . ALL. SOILS GPOSW WRING LAND DISNRWICE MINTY (SiRPFNC GRADING, UTILITY INSRN1Ai S. STOCKPILING.FIWHG, RC) SMALL BE KEPT IN A ROIIGXgFD 4 COEM BY BPPWG OR DISCING ALONG LAND CONTOURS UNTIL MULCH, VEGETATION, OR OTHER COMPONENT ERIC CONTROL IS INSTALLED. NO sORS IN AREAS i OUTSIDE PROJECT SIRER FIGHTS OF WAY SHALL REMAIN EXPOSED BY LAND D RTUANUS AUD IY R OR MORE THAN Tx RTY 30) DAYS BEFORE REQUIRED TEMPOPMY 'lam .7i O PERMANENT EADMNI CONTROL NINE SEW/MULCH RANOSCAPNG RC) 5 I.WfD LESS E APPRaW eI THE SHAMROCK UTILITY.UTILITY.City of Fort Collins, Colorado 5. ME PROPERTY SISAL BE MATTERED AND "WANED AT ALL TIMES DURING CMSTINCTION ALMI SO AS TO PREVENT WIND -CAUSED EROSION. ALL NATO UTILITY PLAN APPROVAL WSTIRBXIG ATO MACS SHALL BE IMME Y DISCBNXNUEO WHEN FUGDM DUSK IMPACTS AQYCE r PROPERTIES AS DRERMINED BY THE CLY OF FEW COI1W9 MPItOKD�.�. Wb J EROmRwxG DePARRMVIr '� '"-5. ALL IEVPoRIRf ($IRVCRVRLL) EROSON CONTROL MEASURES SHALL BE INSPECTED AND RE➢NRE TUR RECONSTRUCTED AS NECESSARY AFTER EACH RUNOFF EVFM CitY Nglu ( • •+\ '` ` '` — — -- — _ - - IN CA ER iDDO AS RE WNIW�VF R W FORMWCE OF THEIR WRING FUNCTION. MEMBER SE EWS, PARTICULARLY THOSE ON PAYED RCILYUY SURFACES. CHECKED BC: A Ti- F M A MANNER AND LOCATION SO AS MUST i0 CHASE THEIR CLEDI INTO ANY ORATUCEYtl.Y. 6.1n�.eaw, AL ENOINT� p \O ). NO sdL STOCKPILE SISAL BACKED III OIN RUT N HESLIE ALL SO L STOCKPILES SAL BE P iED FROM DOCUMENT TRAMMI BY SURFACE ROUGH , ONEENJD By. 6 k CROS51`AN / �^' T- -�v Y MATERUG. AND PERIMETER SILT F ION. AM mIL STOCKPILE REWJNINC AFTER Re O4R SISAL SEEDED AND MULCHED. A Wr ^R r [ { m e. CRY ORIANMN:E ERS THE TRM:KINK DWW�NG OR DEPDSTTA OF SONS OR AM OTHER NESTLE ONTO CRY STRERs BY OR FROM ANY Vwx . ANI li 12 .5� $ !$ ^ GHEgKED BY J. tl' '� � `B � IHYMRIN4N OFP091EO IFJNL SHALL BF CLEARED MEWIELY BI ME CQVIPICNOR. - No Revisions B . Dale MABRf Fi RLWiICO ql HEWS. A-xEpl xYpY'M /GGVS ME OJ/=ONTO ' I 9. ALL IECpIMEM4N OF ME FIFNL GRADING AND EROSION CINTROL PVN AND SUDS PM ON 10. Nl EROSKKI i'LMINOL CONTEST GN BE FWXO OX OEIM SXEE 10 11, REfFR RI COMTMR'IION SEWFNCF (SHEET.5) FOR IHSIAIAIOH AND RFMp'K OF ALL EJIOSIO� DEVELOPMENT SISAL BE COMPUED WITH. COMPOL DENCES. CHECKED BY, C'NECILED BY: �rsq or I--cI snBec ` /2- NORTHERN ENGINEERING SERVICES -420 SOUTH HOWES SUITE 202 -FT. COLLINS. COLORADO 90521 _. (970) 221-4156 Ik Project: 9839.00 CYF Print Date : rniI SE, 'N Er :w PmHI q wMNa sm ^<- LANDINGS BAY \ GRADING PLAN ! - -][ SCALE 1"=30''. DESIGNER DES CHECKED BY: RAC DRAFTSMAN:ACADR14 PREPARED: 06/04/99 mil ... .....