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HomeMy WebLinkAboutDrainage Reports - 08/21/1992oPERTr OF FORT COLLINS UTIUTIES < ._ " . "FINAL' DRAINAGE INVESTIGATION 1' POTTS' - P. U. D. A PROPOSED 22 UNIT MULTI -FAMILY RESIDENTIAL COMPLEX FORT COLLINS, COL 0RADO Prepared for MCC,IfI I�EMURE ONE 150 East 29th Street #? Suite 200 Loveland, Colorado $0538 May 4,1992 ( REVISED July 31, 1992) Project No. VI:A-071-92 PREPARED BY: ' lffi�IIB Engineering Associates 150 East 29th Street, Stine 225 Loveland, Colorado 80538 Telephone: (303) 663-2221 Final Approved Reoord Civil and Environmental Engineering Consultants July 31, 1992 Project No. PLA-071-92 Mr. John Freeman, Architect ARCHITECTURE ONE 150 East 29th Street Suite 200 Loveland, Colorado 80538 Dear Mr. Freeman, The enclosed report represents the results of the Final Drainage Investigation for POTTS' - P. U. D., a proposed multi -family residential complex to be located on a 1.67 f acre parcel at the Southwest corner of the Matador Apartments - Phase IV in the City of Fort Collins, Larimer County, Colorado. This investigation was based upon the proposed site development plan; proposed site grading plan; on -site observations; and available topographic information. The investigation was performed in accordance with the criteria established in the City of Fort Collins "Storm Drainage Design Criteria and Construction Specification Standards" manual. Thank you for the opportunity to be of service to you. If you should have any questions, please feel free to contact this office. Respect y Submitted, Dennis R. Messner, P.E. MESSNER Engineering Associates DRWmkm REVISED JULY 31, 1992 Enclosures Civil and Environmental Engineering Consultants 150 E. 29th Street, Suite 225 Loveland, Colorado 80538 Telephone: (303) 663-2221 kF J',IPDKG • M Letter of Transmittal Table of Contents Scope Site Description Existing Conditions Proposed Development Erosion Control Measures Conclusions and Recommendations Summary Sheet ii 2 2 3 Vicinity Map Existing Conditions Exhibit Grading & Drainage Plan Landscape Plan Calculations Original Study and Design (for Matador Apartments - Phase IV) ii SCOPE The following report represents the results of a final drainage investigation for a proposed 22 unit multi -family residential complex to be located on a 1.67± acre parcel of land situated in the Southeast Quarter of Section 15, Township 7 North, Range 69 West of the 6th P.M., Larimer County, Colorado. The site is located at the Southwest corner of the "Matador Apartments - Phase IV" in the City of Fort Collins.The investigation was performed for ARCHITECTURE ONE. The purpose of this investigation is to determine the effects of the proposed development on the area's existing drainage conditions and to determine the improvements, if any, and the appropriate sizing for proposed improvements so that it may be incorporated with the construction of the project. The conclusions and recommendations presented in this report are based upon the proposed site development plan; proposed site development construction plans; on -site observations; and the available topographic information. The analysis was performed in accordance with the City of Fort Collins "Storm Drainage Design Criteria and Construction Standards" manual. SITE DESCRIPITION The site is irregular in shape and contains approximately 1.67± acres. The site's East-West dimension varies but is considered to average approximately 175 feet. Its North -South dimension is approximately 450 feet. The site abuts the easterly right-of-way of the Larimer County Canal #2. The site is located approximately 350 feet south of West Elizabeth Street and 700 feet west of City Park Avenue. The site is located In the SPRING CREEK DRAINAGE BASIN. EXISTING CONDITIO The site is presently vacant and undeveloped. The ground cover consists of native pasture grasses and a few volunteer trees. The ground slopes toward the northeast and is relatively flat with grades ranging from 0.75% to 1.5%. The "Soil Survey For The Larimer County Area" prepared by the U.S.D.A., Soil Conservation Service, indicates that the upper layer soils are a sandy clay loam. "The Survey" indicates that the soils have a slow to moderate runoff potential and have slight to moderate wind and water erosion potential. This site falls under the "Moderate" erodability zone on the City's "Wind and Rainfall Erodability Maps." The area surrounding the site is virtually fully developed. As previously stated, the Larimer County Canal #2 forms the western boundary of the site. The area to the west of the canal is a single-family residential subdivision known as Fairview. To the north of the site are a Taco Bell restaurant and a Diamond Shamrock convenience store. The areas immediately adjacent to the site on the north consist of parking lots for the Taco Bell and the C. B. & Pott's restaurants. The area adjacent to the site on the east consists of the Matador Apartment complex. The site does not receive runoff from the surrounding properties. The runoff from the area to the west is intercepeted by the Larimer County Canal #2. Runoff from the area to the north flows to the north and east away from the site. Runoff from the area to the east flows to the north and east away from the site. Runoff from the site flows overland to the C.B. & Potts' parking lot. The flow is detained within this parking lot and discharged through a restricted orifice into the Diamond Shamrock drainage system. The flow is carried in 8" dia. drain pipes and eventually discharges into a 15" dia. storm drain that flows east in West Elizabeth Street. 1 The proposed development of the site is to consist of constructing 22 multi -family residential units along with the associated access drives and parking. The runoff generated on the major portion of the site is to be routed overland to the access drive. The drive has been designed to be graded to a low point situated near the southeast corner of the site. A storm drain inlet is to be constructed at this point in order to intercept and collect the site's storm runoff. The rate of discharge of the storm runoff is to be controlled by placing an orifice plate at the inlet end of the pipe outfalling from the storm drain inlet. The runoff will be detained and will pond in the access drive and parking areas due to the restricted release rate. A 15" dia. storm drain pipe is to be installed to route the flow to the north and east through the C. B. & Potts' parking lot to an existing 15" dia. storm drain that is located along the easterly boundary of the C.B. & Potts' parking lot. Should the inlet become plugged or a storm of greater than the design intensity occur, the excess runoff will flow overland in the swale along the easterly property line to the C. B. & Pott's parking lot. The area in the northeast corner of the site that is not routed to the access drive detention area will also flow overland to the existing C. B. & Pott's parking lot. The Pott's parking lot has been constructed to detain the flow that is generated onsite. The existing detention is provided through a reduced size of outlet pipe that discharges into the existing detention area located on the Diamond Shamrock site to the north of the parking lot. The discharge pipe from the existing inlet in the C. B. & Potts' parking lot is to be rerouted to discharge into the proposed 15" dia. storm drain. This routing will retain the intent of the original drainage pattern and design. The overland flow from POTT'S - P.U.D. and the parking lot is to be detained in the parking lot before flowing to the existing 15" storm drain. Should this outlet be plugged, the excess water will overtop the curb at the northeast corner of the parking lot and flow through adjacent parking lots to the north and east until reaching W. Elizabeth Street. The existing Matador apartment complex flows that reach the detention pond will not be detained. VMkIlmentaxim Erosion control considerations have been made based upon the short term, i.e., during construction activities and the long term, through the life of the facility. The long term measures that are to be incorporated into the project in order to reduce erosion are the proposed methods and materials to be used to provide a surface covering for the parking areas, walkways, driveways and the landscaped open areas. The structures and hard surfaced areas will provide a covering to deter erosion. The landscaping to be established will be a combination of plantings and ground covers to deter erosion. The construction activities are anticipated to be performed within the following schedule: August 15 thru September 15, 1992 install utilities; September 1 thru September 30, 1992 perform earthwork and construct access drive; September 1, 1992 begin construction of initial 6 unit structure; October 1, 1992 begin construction of remaining structures; September 1, 1992 thru March 1, 1993 construct apartment structures; March 15 - April 15, 1993 install landscaping. This schedule is proposed as the conservative time line with the anticipation that actual construction will proceed on a faster schedule. In any case the site will be "open" and subject to water and wind caused erosion for an extremely short period of time. The entire site is to be "open" for only one month. The site is buffered on the north and west by existing development with moderate sized trees and structures. Also, please note that the surface will be interspersed with foundations and structures in various stages of ongoing construction. Therefore, the criteria to minimize the "open" areas to dimensions of less than 200 ft. becomes moot since there will be no distance greater than 200 ft. without some form of construction occuring. Wind erosion control measures should not be necessay. 2 The erosion control methods to be incorporated into the construction of the project are methods associated with controlling drainage related erosive actions. "Area Inlet Filter Straw Bales" are to be placed at the proposed storm drain inlet onsite. "Straw Bale Dike Channel Application" is to be placed along the proposed swale that is to located adjacent to the eastern boundary of the site and a "Silt Fence" is to be placed along the northern boundary of the site. The proposed methods will not meet the "Effectiveness" rate as defined in the City's criteria. Additional measures such as roughening the ground, placing mulch, seeding for a temporary cover, or sodding are not practicle and would be ineffective in this particular situation. The seasonal timing of the construction would not allow grasses to become established and the necessity to move equipment and stockpile building materials around the site will negate any use of mulch or soil roughening. CONCLUSIONS AND RECOMMENDATIONS 1. The proposed development will retain the existing drainage patterns. 2. The site is located in the SPRING CREEK DRAINAGE BASIN. The site is not located within the floodway or flood plain. The proposed site drainage improvements conform with the Spring Creek Drainage Basin Master Plan. 3. All development is to be performed in accordance with City of Fort Collins Standards and Specifications. 4. Detention of stormwater is to be provided. Due to existing limitations in the City's storm sewer system located within the immediate vicinity, the drainage system for this proposed development has designed based upon the available capacity in the existing drainage system. The "total" POTT'S - P.U.D. has been designed to detain a minimum of 9,278 cu. ft. and release the runoff flow at a maximum rate of 0.79 c.f.s. A minimum detention volume of 7,047 cu. ft. is to be provided onsite. The maximum release rate for the detention onsite is to be 0.58 c.f.s. An additional volume of 2,256 cu.ft. is to be incorporated with the existing detention facility located in the adjacent C. B. & Pott's parking lot. The minimum volume for the combined parking lot and apartment runoff is to be 7,660 cu. ft. at a maximum release rate of 0.39 c.f.s. 5. The site grading and drainage plan has been prepared based upon the established criteria and the physical constraints and limitations present onsite and within the immediate vicinity of the project site. The location and size of the onsite detention area is dictated by existing physical constraints and the configuration of the proposed development plan. Since the proposed detention area is to be located in the access drive for the site, it is extremely important to understand that there will be a greater requirement to properly maintain the access drive and to control litter and debris on the site. There is a greater maintenance requirement in this situation due to the residents daily use of the detention area for parking and pedestrian access. It is recommended that a snow removal program be established and that sweeping of the paved area be performed on a routine basis. These maintenance operations will lessen the likelyhood of ice build-up and aid in the intended function of the proposed drainage facilities. 6. The City of Fort Collins Standards for temporary erosion control measures are to be incorporated with the construction activities. Suggested means to be utilized for the water borne materials are indicated on the site grading and drainage plan. A varience to the "Standards" is requested due to the intensity of the construction. Drainage Summary for Proposed POTT'S - P.U.D. to be located on a portion of "Matador Apartments Phase IV" in the City of Fort Collins, Colorado Existing Conditions: Total Area = 1.67 ± acres Onsite + 1.72 ± acres Offsite = 3.39 ± acres Rational "C" factor = 0.20 Onsite + (0.83 @ 0.62 ac. + 0.15 @ 1.10 ac. Offsite) Onsite Runoff. Q 2 = 0.55 c.f s. moo = 1.92 c.f s. Offsite Flows: Q 2 =1.39 c.f s. Qioo = 4.86 c.f s. Total Runoff: Q 2 = 1.94 c.f s. Qioo = 6.78 c.f s. Developed Conditions: Total Area = 1.67 ± acres Onsite + 0.62 ± acres Offsite = 2.29 ± acres Rational "C" factor = 0.62 "avg." Onsite 0.62 ac. Q 0.83 + 1.10 ac. @ 0.15 Offsite) Onsite Runoff: Offsite Flows: Total Runoff: kPITM51111141Mui Q 2 = 2.61 c.f s. Q 2 = 1.29 c.fs. Q 2 = 3.90 c.f s. Qioo = 9.44 c.f s. Qioo = 4.66 c.f s. Qioo = 14.10 c.f s. A combination of On -site and Off -site detention facilities are proposed totalling a minimum of 9,303 cu.ft. of storage volume at a maximum discharge rate of 0.79 c.f.s.. (This volume is directly attributable to POTT's - P.U.D., only.) 7,047 cu.ft. of storage is to be provided on -site. An additional 2,256 cu. ft. of storage is to be provided off -site within the existing C. B. & Pott's parking lot that is located immediately to the north of the site. The total volume for the combined POTT'S -P.U.D. and the C. B & Pott's parking lot is to be a minimum of 7,660 cu.ft. Drainage Basin Statistics: Gross & Net Platted Area: A = 1.669 ± Acres Gross & Net Area Rational "Cavg." Factor: "Cavg." = 0.62 Onsite Detention: 5,776 c.f./ac. Offsite Detention: 5,013 c.f./ac. Total Detention Volume = 9,303 cu. ft. = 0.214 ac.-ft. Basin: SPRING CREEK XHI :ITS VICINITY MAP I I _I�INE - 5022 -16 .777 Micinty Map for POTIFS' - P. U. D. located in SE1/4 Section 15, Township 7 North, Range 69-West of the 6th P3L Fort Collins, Colorado 11 —5SD T- I Existing 15°dia. I Storm Drain ! A a � �-Exist.Inlet z A �1 ca J 2- Exist. 8 la. u e I I IJ I I Y z0 C:] O J U J ¢ w 13 ¢ U 3 i d- ia. Outlet Pipe U O d CD n 0 0 0 E— Storm Water Detention in Parking Lot ---15"SD------ — i <X V Ape = I.IO acres + - do Q2 = 0.54c.f.s. Exist. Inlet Qloo= 1.90c.f.s. 3 Area=O. cres ' 1 Q2 = 0.85 c. f. .-Qioc--2.96 c. a Storm Water Detenti in Parking Lot 15"SD Exist Inlet Exist. 15°dia. Storm Drain 41— .A-1— —� M Exist Inlet --- 0 --- W + r- --e— Area = 1.67 acres Q2 =0.55 c.f.s. 0 oo = 1.92 c. f.s. — 5040 O• 0� a °°`°J S / TE 41 �n\� NOTE: The "Existing Ground Contours" shown hereon do not depict the soil that has been excavated from adjacent Parking lots and stockpiled on the Site F Ric Top of North/East Canal Bank If Nt4, NORTH Scale: ["=50' m X W z O F— z O U CD Z U) W POTTSI — P. U. D. M.E.A. #: PLA-071-92 C��C�� r e �Bo�� Client: ARCHITECTURE ONE By: DRM Project No. PLA-071-92 Date: July 31, 1992 Calculations for Drainage Investigation for POTTS' - P.U.D. located in the SE1/4 of Section 15, Township 7 North, Range 69 West of the 6th P.M., City of Fort Collins, Larimer County, Colorado Total Site Area = 1.67 ± acres The proposed development of the site is to consist of the construction of 22 multi -family residential units to be located in 5 separate structures. EXISTING CONDITIONS - RUNOFF COEFFICIENT From Table 3 - 2 of City of Fort Collins Design Criteria manual: Rational "C" Factor = 0.20 for Unimproved Areas Therefore, at the Existing Condition for the POTTS - P.U.D. Site, 'U avg = 0.20 The site and adjacent areas drain to the existing C. B & POTT'S parking lot located to the northeast of the site. The additional areas that presently drain to the existing C. B. & POTT'S parking lot are: a portion of the most westerly apartment units located in the "Matador Apartments" complex and the C. B. & POTT'S parking lot itself. The areas include: POTT'S - P.U.D. = 1.67 acres± C. B. & POTT's parking lot = 0.62 acres± Matador Apartments = 1.10 acres± Total = 3.39 acres± 40 From Tables 3 - 2 & 3 - 3 of the City of Fort Collins Design Criteria manual: Rational "C" Factor = 0.15 for Lawns and Landscaped Areas = 0.95 for Roofs, Decks, Patios, etc. = 0.20 for Undeveloped Areas = 0.83 for Parking Lot (per J. H. Stewart & Assoc. report dated: 12-3-90) "C"avg : Lawns and Landscaped Areas = 39,116 sq.ft.± = 0.90 acre ± Roofs, Decks, Patios, etc. = 8,800 sq.ft.± = 0.20 acre ± Undeveloped = 72,714 sq.ft.± = 1.67 acre ± Parking Lot = 27.000 sq.ft.± = 0.62 acre ± Total Site = 147,630 sq.ft.± 3.39 acre ± "C" avg = K39,116 x 0.15) + (8,800 x 0.95) + (72,714 x 0.20) + (27,000 x 0.83)) + 147,630 = 0.35 Therefore, at fisting Condition for Total area draining to the C. B. & POTTS parking lot use - "C"avg = 0.35 TIME -OF -CONCENTRATION AT EXISTING CONDITION Existing Conditions ® Sub -Basin #1 (Onsite only): ' Time of Concentration (Overland) = To(min.) = 1.87 [ 1.1 - (Cf x C) ] 4L(ft.) + 34S(%) Distance, L = 200'± Elev. Diff. = 5042 - 5040 = 2' Page 1 of 16 Client: ARCHITECTURE ONE By: DRM Project No. PIA-071-92 Date: July 31, 1992 TIME -OF -CONCENTRATION AT EXISTING CONDITION (cont.) Slope, S = 2'+ 175' = 1. 1 % Cf @ 2 Yr. Storm = 1.00 Cf @ 100 Yr. Storm = 1.25 2 Yr. To = 1.87 [1.1- (1.00 x 0.20)14200 + 341.1 = 23.05 min. 100 Yr. To = 1.87 [1.1- (1.25 x 0.20)]4200 + 341.1 = 21.78 min. Time of Concentration (Channel): Grassed Waterway w/ 140' length @ 0.8%, (Refer to attached Fig. 3 - 2) Tch=L+Vx60= 140 + (1.5 x 60) = 1.55 min. Tc=To+Tch =23.05+1.55=24.60 Therefore, at Existing Condition - Onsite,Sub-Basin #1, Tc = 25 minutes Existing Conditions with Offsite areas. Sub -Basins #2 & #3 draining to the existing C. B. & Pott's Barking lot: Time of Concentration (Overlot to existing inlet): Paved parking lot w/ 120' length @ 1.2%, Velocity = 2.2 ft./sec. (Refer to attached Fig. 3 - 2) N Tch = L + V x 60 = 120 + (2.2 x 60) = 0.9 min. Tc = To + Tch + To1 = 23.05 + 1.55 + 0.90 = 25.50 Therefore, at Existing Condition - Offsite Sub -Basins #2 & #3 Tc = 25 minutes RUNOFF AT EXISTING CONDITION Runoff, Q =C xIxAxCf Runoff from On -site, Sub -Basin #1, and Offsite, Sub -Basins #2 & #3, draining to the existing C. B. & Pott's parking lot at Existing Conditions:: Refer to the following Tabular Form on Page 3 Page 2 of 16 I A Op U'-, r -4 000 m {r CD � CD c q 4 rl ri ci A o C .0 GV CV CV � rr� U k U m M co CO 00 k C C w U k U m m 10 k C C C d p _ ri 4 r w w o o m d U Ci cm 00 U - 03 y l— O cq v r/ rl C I CV co ao f ik iR A a y 0 a o c U a' y a cd a a Q ® b QD ca Cd 6 U � o U cd 0 0 rt 0 41 cn v; cq O cq CD 00 Cr4:M maornN v rl 4 M c1 CO rr CO CO CD ci N v E+ U k U N d0 M oo t- dp k C C ri U k U cq d CEO k C C C d wka cq N c . rl ri r4 a� - G*. U - rl rl o Cq M f A a a d x 3 � a U � m a Client: ARCHITECTURE ONE Project No. PIA-071-92 By: DRM Date: July 31, 1992 RUNOFF AT EXISTING CONDITION (cont.) Due to the limited capacity of the existing storm drain that will be receiving the runoff, the available capacity in the existing storm drain is to be used as the control release rate for the detention facilities rather than basing calculations on the "normal criteria" release rate of Q2 at the undeveloped condition. The existing 15" dia. Storm Drain is located at the easterly boundary of the existing C. B. & Pott's parking lot: The original plan for Matador Apartments - Phase IV indicates that two (2) - 8" dia. VCP pipes @ 0.4% slope were to be installed in order to control the discharge into the existing 15" dia. storm drain. (Refer to the attached M & I, Inc. Report and Plan) Therefore, the capacity of the two pipes is estimated to have been: Q = 1.486/n A R*2/3 S*1/2 = [1.486 + 0.0131 x (0.35)(0.33/2)*2/3(0.004)*1/2 = 0.76 cfs (per 8" dia. pipe) Q Total = 2 x 0.76 = 1.52 cfs Future development potential exists at the Matador Apartments even though the detention area designated on the "Phase IV" plan has not been constructed. Therefore, based upon the potential future development of 1.10 acres, the apartment complex's share of the available capacity is: MQ2 = 0.30 x 1.65 x 1.10 x 1.0 = 0.55 cfs (Based upon Q2 at Existing Conditions) The controlled discharge rate from the existing C. B. & Pott's parking lot is 0.18 cfs (per the J. H. Stewart & Assoc. 12-3-90 report) The available discharge rate for POTT's - P.U.D. is therefore: Q Pott's-P.U.D. = QTotal - (QMatador + QC.B.&P.) = 1.52 - (0.55 + 0.18) = 0.79 cfs PROPOSED DEVELOPMENT - RUNOFF COEFFICIENT From Table 3 - 3 of the City of Fort Collins Design Criteria manual: Rational "C" Factor = 0.15 for Lawns and Landscaped Areas " 11 to = 0.95 for Roofs, Decks, Patios, etc. " to to = 0.95 for Asphalt and Concrete Streets, Drives, and Parking "C"avg : Lawns and Landscaped Areas = 29,802 sq.ft.± = 0.68 acre ± Roofs, Decks, Patios, etc. = 15,912 sq.ft.± = 0.37 acre ± Streets, Drives, and Parking = 27.000 sq.ft.± = 0.62 acre ± Total Site = 72,714 sq.ft.± 1.67 acre ± "C" avg = {(29,802 x 0.15) + (15,912 x 0.95) + (27,000 x 0.95)) + 72,714 = 0.62 Therefore, at Proposed Condition use "C"an = 0.62 for the Total Site Page 4 of 16 Client: ARCHITECTURE ONE By: DRM Project No. PLA-071-92 Date: July 31, 1992 PROPOSED DEVELOPMENT - RUNOFF COEFFICIENT (cont.) On -Site @ Sub -Basin "A": "C"avg : Lawns and Landscaped Areas = 20,688 sq.ft.± = 0.47 acre ± Roofs, Decks, Patios, etc. = 10,084 sq.ft.± = 0.23 acre ± Streets, Drives, and Parking = 22.340 sa.ft.± = 0.52 acre ± Total Site = 53,112 sq.ft.± 1.22 acre ± licit avg = ((20,688 x 0.15) + (10,084 x 0.95) + (22,340 x 0.95)) + 53,112 = 0.64 Therefore, at Proposed Condition use "C"avg : Lawns and Landscaped Areas Roofs, Decks, Patios, etc. Streets, Drives, and Parking Total Site "C"avg = 0.64 for Sub -Basin "A" = 6,421 sq.ft.± _ = 3,380 sq.ft.± _ 0 sq.ft.± _ 9,801 sq.ft.± "C" avg = ((6,421 x 0.15) + (3,380 x 0.95) + (0 x 0.95)) + 9,801= 0.43 11wrefore, at Proposed Condition use On -Site @ Sub -Basin "C": "C"avg : Lawns and Landscaped Areas Roofs, Decks, Patios, etc. Streets, Drives, and Parking Total Site 0.15 acre ± 0.075 acre ± 0.00 acre + 0.225 acre ± "C"avg = 0.43 for Sub -Basin W _ 2,893 sq.ft.± = 2,448 sq.ft.± = 4.460 sgft.+ = 9,801 sq.ft.± = 0.07 acre ± = 0.055 acre ± = 0.10 acre + 0.225 acre ± licit avg = ((2,893 x 0.15) + (2,448 x 0.95) + (4,460 x 0.95)) + 9,801= 0.71 Therefore, at Proposed Condition use Off -Site @ Sub -Basin "D": "C"avg : Lawns and Landscaped Areas Roofs, Decks, Patios, etc. Streets, Drives, and Parking Total Site "C"avg = 0.71 for Sub -Basin "C" 4,300 sq.ft.± _ 0 sq.ft.± _ 22.700 sq.ft.± _ 27,000 sq.ft.± 0.10 acre ± 0.00 acre ± 0.52 acre + 0.62 acre ± "C" avg = ((4,300 x 0.15) + (0 x 0.95) + (27,000 x 0.95)) + 27,000 = 0.83 Therefore, at Proposed Condition use "C"avg = 0.83 for Sub -Basin 'D" Off -Site @ Sub -Basin "E" (Matador Apartments): Same as at Existing Undeveloped Condition Therefore, at Proposed Condition use "C"avg = 0.30 for Sub -Basin' ' Page 5 of 16 Client: ARCHITECTURE ONE By: DRM Project No. PIA-071-92 Date: July 31, 1992 PROPOSED DEVELOPMENT -TIME OF CONCENTRATION Proposed Conditions - Onsite ® Sub -Basin "A": Time of Concentration (Roof to Ground) = 5 minutes Time of Concentration (Ground to Street): Tomin.) = L(ft.) _ [Vel. (ft./sec.) x 60 min./sec.] Based upon Velocity for 2% Grassed Waterway with L = 165' ± (from Fig. 3 - 2) Vel. = 2.2 ft./sec. Time of Concentration (Street Flow): T(min.) = L(ft.) + [Vel. (ft./sec.) x 60 min./sec.] Based upon Velocity at 2% for 40'± of Paved Cross Slope and 0.44% for 60'± of Gutter Slope (from Fig. 3 - 2) Vel.(Pavement) = 2.8 ft./sec. & Vel. (Gutter) = 1.5 ft./sec. TTotai = TRoof + Tc + Ts Tc = 165 =- [ 2.2 x 60 ] = 1.25 min. Ts=40=[2.8x60]+60+[1.5x60]=0.24+0.67=0.91min. TTotal = Ts +Tc + Tr Therefore, T = 1.25 + 0.91 + 5.00 = 7.16 min. 40 Tc = (L 180) + 10 (from Equa. 3-4 of Urban Drainage & Flood Control District - Criteria Manual) Tc = (265 � 180) + 10 =11.47 min. Therefore, USE 10 minutes as Time of Concentration for Onsite Concentration at Area Inlet located in Sub -Basin 'IN' TTotai = TRoof + Tc + Tg Time of Concentration (Foundation to Grassed Swale): Tc = 0 since L = 15' ± Time of Concentration (Along grassed Swale Cam) East Boundary of Site to existing C. B & Pott's parking lot): T((mnn.) = L(ft.) _ [Vel. (ft./sec.) x 60 min./sec.] Based upon Velocity for 1% Grassed Waterway (from Fig. 3 - 2) Vel. =1.6 ft./sec. Tg=200+[ 1.6x60]=2.08min. TTotai = TRoof+ Tc + Tg = 5.00 + 0.00 + 2.08 = 7.08 min. ' Tc = (L + 180) + 10 = (200- 180) + 10 = 11.11 min. Therefore, USE 10 minutes as Time of Concentration for Onsite Concentration at Sub-Basin'U' Page 6 of 16 Client: ARCHITECTURE ONE By: DRM Project No. PIA-071-92 July 31, 1992 PROPOSED DEVELOPMENT - TIME OF CONCENTRATION (cont.) Proposed Conditions - On -site @ Sub -Basins "C": TTotai = TRwf + Tc + Tg + Ts Time of Concentration (Overland from foundation to Access Drive, Tc): Based upon Velocity at 2.0% for 50'± (from Fig. 3 - 2) Vel.(Overland) = 1.0 ft./sec. Ts=50+[1.0x60]=0.83min. Ts = 0 Due to no swale in this sub -basin Time of Concentration (Access Drive Flow, Ts): Based upon Velocity at 1.0% for 85'± of Access Drive (from Fig. 3 - 2) Vel.(Gutter) = 2.0 ft./sec. Ts = 85 + [ 2.0 x 60 ] = 0.71 min. TTotal = TRoof + Tc + Tg + Ts = 5.00 + 0.83 + 0.00 + 0.71= 6.54 min. Tc = (L + 180) + 10 = (85 + 180) + 10 =10.47 min. Therefore, USE 10 minutes as Time of Concentration for On -site Concentration at Go Sub -Basin "C" Off -site ® Sub -Basin "D", existing C. B. & Pott's parking lot: Time of Concentration (Parking Lot Flow, Tp): Based upon Velocity at 1.2% for 250'± of Parking Lot (from Fig. 3 - 2) Vel.(Gutter) = 2.2 ft./sec Tp = 250 + (2.2 x 60) =1.89 min. T = T"B" + Tp = 6.54 + 1.89 = 8.43 Therefore, USE 10 minutes as Time of Concentration for On -site & Offsite Concentration at Sub-Basin'D" PROPOSED DEVELOPMENT - RUNOFF Refer to the following Tabular Form on Page 8 for the runoff, Q, from Sub -Basin "A" concentrating at the proposed area inlet at the southern end of the access driveway on -site and from Sub -Basins "B", " G% "D" & "E" concentrating at C. B. & POTT's existing parking lot: Page 7 of 16 W z 0 cq cil 19 cq A rn 4. ko N m OMD N v ko 10 413 U'� ko q v cl CV c] CV CV ti C U o a o 0 0 0 0 � rr� w U x U 00 El o co cq ti t- o 14 C 0 C 0 r� U x 0000 O w U O M a 0 0 0 0 0 d y W U S S S S g ci _ r4 r4 .4 .4 4 U N M �- U ' 0 0 0 aq 0 C m N N O1-4 �., eq CCo, PQ U A W A ,3 ~ a ~ c c o m o co 0 U o U U q M O m 0000 0000 M cD m (75 w cq cq cq cq c ti C .. U c •� o 0 0 0 0 v rr� U k 00 N N CO 00 0 0 0 0 U cq U m N coo d x o C o 0 0 y G" N N U o*l, c` q N M d (� d' N OOR U " 0 0 0 0 cd d H N O N OMN Ch o r-q .•-i O C Ccd ,--� q 'o •W) A +°� o m CD cq .. 0 o as ~ o U U a w Cd Wy a o N® Z y3 Z W U C U U U co 0 00 hB V] � 'b cr 0 w 00 ko 0 u N c0 r-i N N k rn ti c u "o O' w v v NaoaoaowwLaoa000w �n�pUpkp��n4to knUnuz ce v c c o 6 6 o c c o 6 6 ko o N O 14 k cq cq k O d ^• U C70 O W T 0 N 09 ko O e! w 0 00 O d� O -to 0 koN N O M GO �l O O N Ify ICj d� 4 C6 N CV CV CV .-4cr U vy� I--1 .+ it A qcq b oo�no CD S S O v CO m 0i N N 1-4CO �� I[D C70 m L� CC X6 4 4 0M CM C4 N N .•'� G O� C- N N M T 3^ ��-4 dO' Lo COO 00 �' S 6C7 L, P v y c w m c Lo N 14 k N N 14 k r� fL w ca z o C co wQ�C vct ova cw z� U F •o � ¢�aa:�a 08i .. ... C.. • U a c M c 09T � u O a onT OZT w 08 H m [fig OZ A 0 0 0 0 0 0 0 0 N O^ O O O O O (laa; oigno) HNflgOA 00 U O ,na W .••. COD O oo � a > a . n VJ +� m cldo�ocq c Cd C C * II 00 O w + + R d ocq N N m m m m m m m m m m m C11 N y �CCCCCCCCCCC C q cv O Gam' O U] + II LO clO ¢ N y 0 O :ta '1 DC .ba "c oi ® � a�3` o5 Cd .O u tOi N cD Ifs ij6 d' M M c4 cV CV �4 .-4 � p W C kO m ►� e5 1 164 � m Cd b 'c O O WC. G.' ko O O 10 O O O 10� S S c0 cq O 00 y II II ^' •� CV N c0 'i l-Z cC L6 4 4 66 ci CV eV -4 rn a� 3 O .�1-4cq cq c� M10cot- M aom �W w'a Cd Cd m vi of cr Va� c� 0 Obi T • LL a i C C\ 091 I— F' LL' o Cr) a Q a 0+ 1 ur4l 001 �fj 07 OZ 0 N O 00 O J N H H Client: ARCHITECTURE ONE Project No. PLA-071-92 By: DRM Date: July 31, 1992 SIZE INLET IN PARKING LOT FOR SUB -BASIN "A" The proposed inlet will be in a sump condition therefore, based on Fig. 5-3 Depth of flow over grate = 41.10 - 39.75 =1.35 ft. Q/sq.ft. = 4.42± cfs/sq.ft. (interpolated) Area of opening =1.39 sq.ft. w/ No. 12 Grate & Frame Q = 1.39 x 4.42 = 6.14 cfs Reduction Factor for sump condition = 80% Q allowable = 0.80 x 6.14 = 4.91 cfs >> 0.58 c.f.s. (Max. release rate) USE City Standard "Area Inlet' DETERMINE PIPE SIZE Q = 1.486/n A R*2/3 S*1/2 Consider 8" dia. Pipe ® 0.50 % Q = 1.486/0.013 x 0.35 x 0.30 x 0.07 = 0.85 cfs>>0.58 Therefore, 8" dia. is sufficient but, USE IN'dia. to comply with Sec. 5.3.2 DETERMINE ORIFICE SIZE FOR SUB - BASIN "A" Determine discharge opening from main detention area located onsite in access drive turnaround (Sub -Basin "A"): Orifice Equation, Q = CA42gh A = Q �- C42gh Q = 0.58 cfs C = 0.65 h = 41.10 - 36.70 = 4.40 ft. (with opening at Center of 15" dia. outlet pipe.) A = 0.58 = [0.65 x 4( 2 x 32.2 x 4.40)] = 0.053 sq. ft. A=w*2 w=CIA w = 40.053 = 0.230 ft = 2-3/4 inches Therefore, Use 2-3/4" x 2-3/4" Orifice Opening to allow for trash. Page 13 of 16 Client: ARCHITECTURE ONE Project No. PLA-071-92 By: DRM Date: July 31, 1992 DETERMINE ORIFICE SIZE FOR SUB - BASIN "D" Determine discharge opening from existing C. B. & POTT'S parking lot detention area, offsite Sub -Basin "D": Q=0.18+0.21=0.39cfs C=0.65 h = 37.15 - 35.15 = 2.00 ft. (Max. HWL to Centerline of 6" outlet pipe) A = 0.39 + [0.65 x 4( 2 x 32.2 x 2.00)] = 0.053 sq. ft. A=w*2 w=CIA w = 40.053 = 0.230 ft = 2-3/4 inches Therefore, Use 2-3/4" z 2-3/4" Orifice Opening to allow for trash DETERMINE DETENTION VOLUME Determine detention volume provided for main detention area located in access drive turnaround, Sub - Basin "A": . Maximum HWL = 41.10 Area Q 35.80 = 100 sq.ft. Area ® 40.50 = 7,100 sq.ft. Inlet Grate Elevation = 39.75 Area ® 40.00 = 1,800 sq.ft. Area ® 41.10 = 11,875 sq.ft. Vol. = 0.25 x [(100 + 1,800) - 2] + 0.5 x [(1,800 + 7,100) + 2] + 0.6 x [(7,100 + 11,875) = 2 ] = VoL ® Sub - Basin "A" = 8,155 cu. ft. > 7,047 cu. ft. therefore, OK Determine detention volume provided in the existing C. B. & POTT'S parking lot, Sub - Basin "D": High water Elevation = 37.15 Area Q 35.80 = 100 sq.ft. Area Q 36.50 = 7,300 sq.ft. Area @ 37.15 = 11,600 sq.ft. Inlet Grate Elevation = 35.80 Area @ 36.00 = 700 sq.ft. Area ® 37.00 = 9,500 sq.ft. Area ® 37.25 = 11,600 sq.ft. Vol. = 0.20 x [(100 + 700) + 21 + 0.5 x [(700 + 7,300) + 2] + 0.50 x [(7,300 + 9,500) + 2 ] + 0.15 x [(9,500 + 11,600) + 21 + 0.10 x [(11,600 + 11,600) + 2] VoL ® Sub - Basin'D" = 9,022.5 cu. ft. > 7,660 cu. ft. therefore, OK Note that this is based upon field verified measurements and confirms the original design calculations for the C. B. & Pott's parking lot. It also takes into account exceeding the top of curb to the back of walk (approximately 0.1'of additional depth.) Page 14 of 16 Client: ARCHITECTURE ONE Project No. PIA-071-92 By: DRM Date: July 31, 1992 DETERMINE ON -SITE SWALE CROSS - SECTION "A - A" The proposed swale along the eastern boundary of the site is to be designed to carry Qioo from on -site Sub -Basin "A" and on -site Sub -Basin "B" Qioo = 7.08 + 0.88 = 7.96 c.f.s. min. Slope along Flowline of Swale = 1.0 % Consider triangular section w/ 12 ft. top width and 1.0 ft. depth A = 6.0 sq. ft. Wp = 12.2 ft. R = 6.0 + 12.2 = 0.493 ngrass = 0.030 Q =1.486 + 0.030 x ( 6.0 x 0.493*2/3 x 40.01) Q = 18.5 c fs. >> 7.96 min. required, therefore at 1.0 ft. depth OK Try @ 0.75 ft. depth A = 3.375 sq. ft. Wp = 9.12 ft. R = 3.375 = 9.12 = 0.370 ngrass = 0.030 Q =1.486 = 0.030 x ( 3.375 x 0.370*2/3 x 40.01) Q = 8.6 cAs. >_ 7.96 mim required, therefore, depth = 0.75 ft. @ "A!'- "A" DETERMINE ON -SITE SWALE CROSS - SECTION "B - B" (Overflow from "A" - "A") The proposed swale at the northeastern side of the access drive turn -around is to be designed to carry Qioo from on -site Sub -Basin "A" onto on -site Sub -Basin "B" Qioo = 7.08 c.f.s Slope along Flowline of Swale = 1.0 %min. Consider same cross-section as for 'B" - "B" Flow, Q, at a depth of 0.75 ft. = 8.6 c.f.s. >_ 7.08 c.f.s. Therefore, use same cross - section as at'B" -'B" Page 15 of 16 DETENTION VOLUME DETERMINATION FOR POTT'S - P.U.D.'TOTAL SITE 1 Time w/ Rainfall (I) Q100 Prop. Vol. 61 Q100 Q dis. Vol. dis. Vol. Diff. (min.) / (in./hr.) (c.f.s.) 6u.ft.) (c.f.s.) (cu.ft.) (cu.ft.) 10 / 7.25 9.38 5630 0.79 474 5156 15/6.00 7.77 6989 0.79 711 6278 20 / 5.20 6.73 8076 0.79 948 7128 25 / 4.60 5.95 8930 0.79 1185 7745 30 / 4.15 5.37 9668 0.79 1422 8246 40 / 3.50 4.53 10872 0.79 1896 8976 50 / 3.00 3.88 11648 0.79 2370 9278 60 / 2.60 3.37 12114 0.79 2844 9270 70 / 2.30 2.98 12502 0.79 3318 9184 80 / 2.05 2.65 12735 0.79 3792 8943 90 / 1.85 2.39 M30 0.79 4266 8664 At Q100 Proposed Q = CIACf = 0.62 x I x 1.67 x 1.25 CACf = 0.62 x 1.67 x 1.25 = 1.29 This is based upon detaining the diffeence between the proposed site conditions with runoff generated by a 100 Year Storm event discharging at a rate of 0.79 cfs, the rate originally designed into the existing Storm Drain system at the Matador Apartments. Note that the detention volume, 9,278 cu. ft., is the volume determined for the entire 1.67± acre POTT'S P.U.D. site if it were to be concentrated in one detention area. ARCHITECTURE ONE POTT' - P.U.D. Proj. No. PLA - 071 -92 Page 16 of 16 REVISED: 7-31-92 By: DRM OFF -SITE DETENTION VOLUME DETERMINATION FOR COMBINED SUB - BASINS 'U' & 'V' Discharge Rate, Q dis., = 0.79 - 0.58 =0.21 c.f.s. Area = 0.225 + 0.225 = 0.45 Ac. ± Runoff Coeff., C = K0.225 x 0.43) + (0.225 x 0.71)1 + 0.45 = 0.57 Time w/ Rainfall (I) Q100 Prop. Vol. @ Q100 Q dis. Vol. dis. Vol. Diff. (min.) / (in./hr.) (c.f.S.) (cu.ft.) (c.f.S.) (cu.ft.) (cu.ft.) 10 / 7.25 2.32 1395 0.21 126 1269 15 / 6.00 1.92 1731 0.21 189 1542 20 / 5.20 1.67 2001 0.21 252 1749 25 / 4.60 1.47 2212 0.21 315 1897 30 / 4.15 1.33 2395 0.21 378 2017 40 / 3.50 1.12 2693 0.21 501 2189 50 / 3.00 0.96 2886 0.21 630 2256 60 / 2.60 0.83 3001 0.21 756 2245 70 / 2.30 0.74 3097 0.21 882 2215 80 / 2.05 0.66 3155 0.21 1008 2147 90 / 1.85 0.59 3203 0.21 1134 2069 At Q100 Prop. Q = CIACf = 0.57 x I x 0.45 x 1.25 CACf = 0.57 x 10.45 x 1.25 = 0.32 Therefore, the portion of the Detention Volume attributed to Sub -Basins "B" & "C" to be provided "Offsite" in the existing C. B. & Pott's parking lot is a minimum of 2,256 cu. ft. at a maximum release rate of 0.21 c.f.s. ARCHITECTURE ONE POTT'S - P.U.D. Proj. No. PLA-071-92 Page 16(a) REVISED: 7-31-92 By: DRM RAINFALL PERFORMANCE STANDARD EVALUATION IYXVJECT: Pott's P.U.D. STANDARD FORM A .AMPLETED BY: Dennis Messner DATE: July 8, 1992 JulJulv 31 1992 DEVELOPED ERODIBILITY ASb Lsb Sqb Sb PS SUBBA$IN ZONE (aC) ]ft(ft) (t) (feet) M M A Moderate 1.22 200 1.2 B Moderate 0.225 150 1.3 c Moderate 0.225 85 1.0 1.67 178 1.19 76.7 MARCH 1$$1 8.14 DESIGN CRITERIA EFFECTIVENESS CALCULATIONS PROJECT: Pott's P.U.D. STANDARD FORM B COMPLETED BY: Dennis Messner DATE: July 8. 1992 Revised u 3 Erosion Control C-Factor P-Factor Method Value Value Comment Bare Soil 1.0 1.0 Pavement (Drives & Walks) 0.01 1.0 Inlet Filter 1.0 0.8 Straw Barrier 1.0 0.8 Apartment Structure 0.01 1.0 Silt Fence 1.0 0.5 MAJOR PS SUB AREA BASIN (t) BASIN (Ac) CALCULATIONS 76.7 A 1.22 Pavement = 0.52 Ac. Apartment = 0.23 Ac. Open Ground = 0.47 Ac. wtd C-Factor = (0.01 X 6.52 + 0.01 X 0.23 + 0.47 X 1.0) / 1.22 = 0.39 wtd P-Factor = 0.8 X 1.0 X 1.0 X 1.0 = 0.8 Eff•= (1 - 0.39 X 0.8) X 100 = 68.8% B 0.225 Structure = 0.075 Ac. Open Ground = 0.15 Ac. wtd C-Factor = (0.01 X 0.075 + 0.15 X 1.0) / 0.225 = 0.67 wtd P-Factor = 0.8 X 0.5 X 1.0 = 0.40 Eff = (1 - 0.67 X 0.4) X 100 = 73.2% C 0.225 Pavement = 0.10 Ac. Structure = 0.055 Ac. Open Ground = 0.07 Ac. wtd C-Factor = (0.1 X 0.01 + 0.055 X 0.01 + 0.07 X 1) / 0.225 = 0.32 wtd P-Factor = 0.5 X 1.0 = 0.5 Eff = (1 - 0.32 X 0.5) X 100 = 84.1% (68.8 X 1.22) + (73.2 X 0.225) + (84.1 X 0.225) ] / 1.67 = 71.5% < 76.7 Variance Requested MARCH 1991 8-15 DESIGN CRITERIA CONSTRUCTION SEQUENCE 1JECT:.FQtt's F.U.D. STANDARD FORM C SEQUENCE. FOR 19 92 ONLY COMPLETED BY:Dennis _Messner DATE: July 8. 1992 Revised July 31, 1992 Indicate by use of a bar line or symbols when erosion control measures will be installed. Major modifications to an approved schedule may require submitting a new schedule for approval by the City Engineer. YEAR MONTH ---------------------- OVERLOT GRADING WIND EROSION CONTROL Soil Roughing 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 Soil Preparation Contour Furrows Terracing Asphalt/Concrete Paving' Other -Structure Constr. VEGETATIVE: Permanent Seed Planting Mulching/Sealant Temporary Seed Planting Sod Installation Nettings/Mats/Blankets Other 1992 1993 1u4.1 Sept Octal Nova Dec.' Jan.IFeb. Mara Apr May June July -----------......... - xxx No Wind Erosion Control Measures Anticipated Due To Site Dimensions and Short Time Frame That Site Will Be Subject To Wind Without Surface Cover. XxXXKXXXKXXXXXXXXXXxXXXXXXXXXX XxXXXXXXXXXXXXKXXXXXXXXXXXXxxx .XXKXXXXXXXXXXXXXXXXXXXXXXXXXXX STRUCTURES: INSTALLED BY MAINTAINED BY VEGETATION/MULCHING CONTRACTOR -%TE SUBMITTED APPROVED BY CITY OF FORT COLLINS ON �, .,DI/SF-C:1989 DRAINAGE CRITERIA MANUAL RUNOFF C 50 30 f- 20 z W L) Cr W 0. 10 Z W a N5 w 3 O V 2 a: W F- 3 1 _.■�, '1-Hum // �mm i�ii� �F IWJM / /A1//I� M.ME . UMFA..C..IFAF" ...no■ .2 .3 .5 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 FREO.UENTLY 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 6 FLOOD CONTROL DISTRICT I . S5 1 I2 9E 0.7 f- w 0.6 Z 0.5 cr w > 0.4 0 f- a 0.3 w 0 c� z ,0.2 0 z 0 a0 0.0 0 I 2 3 4 FLOW INTO INLET PER SO. FT. OF OPEN AREA (CFS/FT2) Figure 5-3 CAPACITY OF GRATED INLET IN SUMP (From: Wright -McLaughlin Engineers,1969) R T'o-Tv S - p IA,C.�. STORM SEWERS DRAINAGE CRITERIA MANUAL Values o1 L and R (full nlull 1.0 1.2 1.4 1.6 1.8 20 2.2. 2.4 2.6 2.8 30 3.2 3.4 3.6 1.0 0.9 0.8 0.7 b 0.6 E A v 8 0.5 t n 41 0 0.4 c q ac 0.1 0.; 0 0 ►N■■■■■■■■■■■■■■■■■■EMON■■■ U10 ■■■■MOURN i�■■■ ■I■■ ■■■■■� HIF),, fII■■■ ■1`,.■■■■■■■■■■■■■■,',IN%AMMO, ■air, ■■■■■■■■■�a�si■ i■■���■ ■■. ..Mi ► ■■■ Kxti■■■■■■ir■■■ ■■► ■■ .■M■■■ri■■■NV►.■■■ ■■I ■■■M►'./■%■■■■�%■■■7■■■■■ ■■1 ■,.%V2■■■ �FA■/.Fll■■ M■■. M■■■■■ ■■BJ■■PAN!j■■■■ ■■■■ ■. ZI.■k,�.04,0: ;.:.N►A...... =,-... IMMIMMMM ,�.►�.. _.,............... ■■■■■ 1I.._•_.M.■■. '/ ■■■■■■■■■■■■i■ice■ MOM 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 r Hydraulic elements ° V , -, and � Vull Qtull Afull ^full IF = Actual velocity of flow (fps) A = Area occupied by flow (ft.- Vfull = Velocity flowing full (fps) Afull Area of pipe (ff.2) q = Actual quantity of flow (cfs) r = Actual hydraulic radius (ft.) Ofuil Capacity flowing full (cfs) Rfull : Hydraulic radius of full pips(ft.) FIGURE 8-1. HYDRAULIC ELEMENTS OF CIRCULAR CONDUITS (2) 1-15-69 Denver Regional Council of Governments (DIRIGINki OITUIDI IMMOIGH %AT :s �=�•, 3�. CONSU LTING ENGIN EERS 4710 SOUTH COLLEGE. FORT COLLINS. COLORADO 80521 • PH. 482-8249 December 14, 1973 Bartran Homes 2048 Manchester Drive Fort Collins, Colorado 80521 RE: Drainage Plan for Matador Apartments, Phase VI Dear Mr. Bartran, Presented herein is the preliminary drainage plan for the Matador Apartments, Phase IV'development. It is the intent of the report to outline a series of improvements which will provide a uniform degree of protection from the anticipated runoff from a 50 year storm frequency of 3 hour duration. EXHIBITS Exhibit No. 1, the preliminary development layout map of the proposed development with contours has been used as the basis for the presentation of the drainage information. Directional flow arrows, drainage basin, boundaries, detention areas, inlet locations and storm sewer sizes and percentages of impervious and pervious land area of each basin are shown on this exhibit. DESIGN CRITERIA Design considerations for drainage structures and improvements were based on anitcipated runoff from a 50 year storm frequency of 3 hour duration as recommended by the City of Fort Collins. The unit hydrograph method was used to determine the amount of storm water runoff expected from the area and the amount of detention volume required to retain the runoff on site. The "Unit Hydrograph" (defined as the hydrograph of one inch of direct runoff from a storm of specified duration) for the area was developed by Black and Veatch in their report on "Storm Water Drainage Facilities for Fort Collins, Colorado, 1971". The amount of runoff as determined by the use of the hydrograph is dependent on the percentages of impervious and pervious land area. These percentages are shown on Exhibit No. 1. December 14, 1973 Page two STORM DRAINAGE AREA No off -site drainage areas are contributory to the area. The area is bounded on the south and east by the Lari.mer County No. 2 Canal and on the north by West Elizabeth Street. The majority of drainage from the existing Matador Complex and the future commercial area will not be contributory to the Phase IV development. DRAINAGE PLAN The general drainage plan for the project is shown on Exhibit No. 1. The intent of the drainage plan is to retain all runoff from the area in detention areas and to discharge the water from these areas at a controlled rate into an existing storm sewer line which parallels the east side of the project. Runoff from Drainage Basin A (1.28 acres), B (0.94 acres) and C (1.58 acres) will be detained in portions of the planned parking lots within the basins. The portions of parking lot to be used for detention areas will be depressed at least 1.0 feet to provide adequate detention volume for the anticipated runoff. Detention area A will cover 0.30 acres and provide 0.30 acre feet of detention volume. Detention area B will cover 0.22 acres and provide 0.22 acre feet of detention volume. Detention area D will cover 0.45 acres and provide 0.45 acre feet of detention volume. The City of Fort Collins requires 0.29 11 acre feet of detention volume for 1.28 acres (Drainage Basin A.) of developed land, 0.18 acre feet for .94 acres (Drainage Basin B), and .37 acre feet for 1.58 acres (Drainage Basin D). Runoff from Drainage Basin C (2.66 acres) will be detained in a detention pond to be built in the northeast corner of the basin. The detention pond will cover 0.25 acres and be at least 2 feet deep. This will provid " .50 ` acre feet of detention volume. The City of Fort Collins requires ;0r.44 acre_ feet of detention volume for 2.66 acres (Drainage Basin C) of developed land. Storm water will be released from the detention areas through controlled outlets. Discharge from the areas will be carried in storm sewer lines which will be conntected to the existing 15" storm sewer line that runs parallel to the east side of the new development. CONCLUSIONS AND RECOMMENDATIONS According to this analysis, storm drainage from a 50 year storm frequency of three hour duration can be retained on the development without flooding the proposed improvements and then released at a controlled rate. It is recommended that: 1. Overlot grading of the development be done in such a manner that drainage will. be carried to a detention area. December 14, 1973 Page three 2. The drainage facilities and detention areas be constructed as shown on Exhibit No. 1. I trust that this report has successfully answered any questions you may have regarding drainage and drainage improvements within the proposed development. If you have additional questions, please do not hesitate to call the undersigned. Very truly yours, M & I, Inc. Larry Stanton, E.I.T. JJames�M./avid ors-;'P.E.-L.S. LS/JMN/sw G n % _.4L_ % _Z1 -.9 oe q Post Office Box 580 % `484 _:Telephone 303 -4220 .. .. ... Fort Collins, Colorado 80527 -7 December 28, -1973 .. . .. .......... Z Mr. t-7 Larry 7.Stanton: . I'; Inc Consulting-'E Engineers 4710.'-South"Col lege Fort Collins.'Colorado =80521:"ey-' 4, —0. —.7 .. ... ... ... _!Z: ..;r_ e' arry D ar- L 7. -I have reviewed the preliminary drainage f an or se,IV of Matador _nApartments -and'found. a -few -items which we would:like to have on the final.: plans :First we ..will need to know the capacity bf the* 15-inch pipe.east from 0 manhole and the amount of water which- is now designed to the northern -most flow into the south end of'this 15-inch pipe. -Also show the capacity of the existing pipe, through* the proposed- -improvements y ou, shouldalso* show, thit"the -four- out let pipes, 'which are proposed,': Ze,,.Iat will n -will,have...to be 'not overtax the existing pipe...-- -Either the slopes flattened to -decrease the:.capacityLin.the.l2.-inc h -7pipes or., the size - of -the outlet-* pipes. could be l6iiWied to 8 inches`i'�: It -should dlso* be -considered: that ntaine ---.--' theseS-inch lines i4ill"n6t"�bein 1"e-asements 'and.. will. not --'be mai dby. the Crty_- of Fqrt_Collins._._.Z:�,_... A 6s hew'developments ..the good . -requir ;Nowfor newi thd City! of -Fort C61111is retain. only :.the additional runoff which is' .generdted bythe development, - ­-np -a 1 runoff This --should. Cut your detention -requirements by.from 60 -t0 80 -percent through :this R If'bA -t is matter -_Pldas�e.` _t'-hesitate to -contact you have.any questions h t don't me ..... ... ... ... Sin6erely:yours _7 No Text i7 I T I o u � Z .. U 43 a . h0 p� 1 M.N. 8-1 g� 41 INV. 16' R.C.P. 53.IS / ' I EXISTING STORM INLET INV. B' V.C.P. 52.T2 INV. e' V.C. P. 53.84 INV, 5' V[.R 55.1, Z j` T�0,r V. 10'R.C.P. 62.39 fl tfHll+� fi7 I µ7iy lii i%'RC-P 54.55 .Q INV. EXISTING N.H. �^�J EXISTING 16' STORM SEWS" V.C.P. TO B TAPPED B 94OUTED INTO EXIST. 15'R .. J INV. ID" R.C.P. 53.34✓ - �r 120• — —�- �' �� GEXISTING 15' d INV. 8' V.C.P. 53.33 I S8' �' �' '� � � � —� Q CU. FT. /SEC. CAPACITY $ S — .-• DETENTION AREA "C" ■ flL _ ° i SURFACE AREA 0.2 ACRES + z �J 8 STORAGE VOLU �. 0 50 ACRE FEET [!T Io' or e' v.c r LINE To I . ' E SAC"FILLED WITH CONCRETE iu 1! O 0.75' Or OUTSIDE NAMETLR ■� TOP OF INLET EV. 56.00 I r 0 PIPE �o ; INV. B VCR! 53. 4 ■ LL O \^T-. \ Y �' I \ I ' ■ a / J �- \` O W W a v TOP OF INLET - I I 8 ■ O W 1 1 ELEV. 57.10 �.Aoa I� DRAT AGE BASIN "C" 9 O W -90 I 1 I wV. C vc.r. ss.Iv I•-2.6 ACRES I u O u) w .- I ! I I I I I ' I I■ I 17% 11 PERVIOUS 83 % PERVIOUS cc PARKING LOT DETENTION AREA "B" ■ m a{I{�{t "ftifla�atatiflal{I{lal{I{I{I{ { is Is I al --suRFACs- Awfiw..� ._ _ alalalftstietia'�a� O v' ems_ _ _ 1 . I STORA .22 ACR —� 1 m `ti i I( al■181{Ial{I{salt■ \ I �"• ((� \ 5059 000 00100 45 _ I DRAINAGE BASIN IIB1I , _ _ y / J / ems- I■I W • 0.94 ACRES , ■_ I I�^� / (] 1 \/ — M.X. 8 2/' z \ J 2 \\ / / 40%IMPERVIOUS v / _ 1. 8- I SIN /r. N. S6 2.- — �• /co M \\ -60%PERVt0U5 ��r \V/ �� ��'� —�� W W 9 \ ■ I INV. E. 5504 V.'W.'.riB.32 ■ P ( � �. ..m \ � l INV 4756.04 1minim i Ills lil Yi Illi/illliril as /'?\ J6+ IIJI I I ' I■Ili■lilllil{I■I■I■1{1{If5{1{5ita4{{ ' I �— ; u i{f{Till! 1{ - \ - - _— , ` kk,� �". r �,_- Ill Il� I ■ I o.40>, TOP OF INLET o I. ' �.. I.. I I I I _ ELEV. 58.°0 i 1 ` SSS T P OF IN E I { r c INV. B" v.c. P. 66.7e )11`��111 `NV o V_e P.°ss.°o I I i �� + I PARKIINO LOT ;DETENTION AREAON Oq0}. r / Q90 1 Ii11I`\ 0 PARKING LOT DETENTION AREA "A'� �. h I _I`' / D A L o141 RI5 S RFPC RF A 3 R[[ S I 1 tVmI 6�U E 0�30 AR EE7 - 570ELU E 5Cf�E FE T / i / I� i 1 / v s !ll ti Af d / M i uRAl1�A ........ \ DRAINAGE BASIN % • \ T2%SMPE I y GL BASIN RDN � 1 ■ C E9 'mom-) -1.20 ACRES 4 \`�_ 20%PERV IOU9� �9 ` w ( 63% IMPERVIOUS y - QS 37% PERVIOUS I ' 1 Big �9QS DRAINAGE ARROWS CATCH BASIN �� II■ul DRAINAGE BASIN BOUNDRYS I ...•.... DETENTION POND BOUNDRYS — STORM DRAIN PIPE (R.C,P.) I I REVISIONS BT—_DATE DESCR._—_— ORA'RN_—`•" }_CNECKED Le'•A DATE Dec. 1975 M & �, INC. � MATADOR APARTMENTS `- !NEE* BY�_OATE. OE ---SCR !GALE !*a Sol APPROVED Cl)7 PpOd pO a>t•o,e. OON/OLT1M0 VIN01NooR• pRAINAGE' PLAN —EXHIBIT NO. I [sm! GATE SCR _ _ E"OR9' COLLINS OOLORAOO PHASE IV ' ; 3 1 I R C0 1BELL f=Awdw 992 ExISTNG L4RDecwm6 KJ RN S �C � G 7 e o0 a POTTS PAWING ISSI I UNDESIGNATED EXIeT m . rmrnNroe MATADOR PARCEL x el 9T m•• � .f=OTTO6LY.p LANDSCAPE/PAVING PLAN SCALE: 1' . 30' 0 LANDSCAPE NOTES 1, ALL P-MT MATERIAL SHALL COMPLY WITH CURMNT AAH STANDARDS, FOR NO. I MATERIAL NURSERY STOCK RANTS TO MEET OR EXCEED SIZED SPECIFIED. 2. ALL OPEN AREAS TO CE SODDED WLESS OTHERWISE SHplµ SOV SHALL BE FESCOt BLEND FREE FROM WEEPS. bD SHALL NOT 5E LAID CLOSER THAN 24" FROM CENTER OF SHRUBS AND 2'PROM CENTER CP TREES. SOD SHALL SE PROTECTED FROM DRYING OUT 3. ALL LANDSCAPE AREAS TO HAVE AUTOMATIC IRRIGATION SYSTEM COTL9ISTTN OF A OOMBMATIW OP POP-YP BROADCAST SPRAY HEADS AND DRIP IRRIWTION DIRARA-OOMRAOTgF� •- -p�r■M (RI.E' R FOR AFFINVAL SEFORE INaTALLATIQI IRRwATILN Sl'Slp1 SIYLL UTILIZE THE RPLLOLNG EOUIP'MENT tqR EOUALA -HAMM TOJCN COMMAND DW PROI CONTROLLER -DRIP ROSGAnOTI FOR ORRIB BEDS -RAmm 1SD4 POP UP SPRAY HEADS IN SOD AREA SPACED 'HEAD TO HEAD. -165 FE SCO SACKFLm FFE VENTER OR MR CITY CODE -HARDIE 700 SERIES ALTO VALVES -ALL CONTROL VALVES TO BE SET IN STM'DARD SIZE VALVE BOXES 4. ALL EXISTING TREES SHALL 5E PRNED TO THE CITY FORESTER'S TEDIUM fidNE STANDARDS". S. EXISTNG TREES TO SE SAVED SHOA.D BE MA D WITH PROMINENT IDENTFICATIGH WHERE TREE TRA%S ARE APT TO BE DAMAGED. THEY SHOULD BE PROTECTED WITH METAL POSTS AND SWJW PEKE. 6. HEAVY EOJIPMENT SIKULD NOT BE ALLOWED TO COMPACT OVER THE SOIL OVER THE ROOT ZONE OF EXISTING TIEEA T. ALL LANDSCAPING MUST BE INSTALLED CR SECURED WITH AN IIdEVCCASLE LETTER OF CREDIT, ESCROW OR FEI6CRS-1410E 0.OID POR I W THE VALUATION AS INDICATED ON THIS PLAN PRIOR TO THE bSUANCE OF A CERTPICATE OF OCCUPANCY, S THE OWNER SHALL PROVIDE FOR PERMANENT CARE AND MAINTENANCE OF OPEN SPACESLANDSCAPING. AND P4JQ IRtl LOTS. * LANDSCAPING CONCEPT dID WANTTES: NO EXISTNG SKNFICWJT TIMES WILL BE CUT. BERMED, LANDSCAPED ISUIPER AREAS WILL 5E INSTALLED AS &INN AT THE PROJECT �SCAPING MAMMALS SHALL OF ARRAN! ED !O SCREEN -� MIDTI LIVYY 1eUT6, Q 6PAMS. AND SURROIImS SHALL INS PROVIDED Ab MI TIR:ADLE plTYffN ADJACENT III AND DECKS. TYPICAL =ANTITIIFe EACH WIT SHALL 5E ALLOWED 2 DECIDUOUS, I CONIi£R'VS AND I INTER- M IAIE CONIFERC US TRIMS. TREES ARE AVERK£D PER-I.NIT O2ANTITIES TO 5E INSTALLED WITH CONSTRUCTION OF EACH SULDING, PATTERNS ANC GR"PING5 6 w_ =RIALS MAY VARY ON DIRfRENT dULDINGS. �IjTN 41HLN OF4.p CsTH PLANT MATERIAL SCHEDULE KEY _ '. G CIN NAME BOTANICAL NAME SIZE $PALING F# 5 RADIA T CRAB MA HI DP'RADIANT' INy CAL PER D IF AP 2b AIIDTRAN PINE PAib NIGRA 6' HEIGHT 15. 00 OD D COLORADO B a SMI PIMA P.➢Y EN5 GLAWCA 6' REIb? AS OO. 61- IS pCTLRE HONEY-OCUITM ALEORBIA TRIACANTHOS NTflHID 2-CAL- W 00 YKYLIE' RL a MARSH LL.5 SEEDLESS ASH FRAXNIS PEIWYLVMICA 2.OAL 4OL MNtlHALL'5 DEEDLESS' JC • M CRWEEN JWIPER JWIP£IOID SCORILORM'CMOOEEN' VWEIGHT 20'O4 EA I SUROM A4 MM TARN ASH SLIm'Y NILYPARIA 2• CAL. PER DRAWING Ti SO TAMMY JWR£R ANIPALD 6AENA'TAYAROCRO IA' 5 Gµ. 4' OC. DV 6 LILAC, COMMON PW E DYAbA WLGARI5 5 GAL, 4' OL. Ka H POTENTILLA, GOLD DRY POTENTLLLA MITICCOA FARMER CQD ROW,_ 5 GAL. 3' OG. AMP9" CHNENSIS OLD GOLD' 5 GAL. 4' OG EC 13 5'JR IM tlRH. CQTACi SJII Q16 ALATW CQTACTA 5 GAL, 4' OG SS 11 5PIMA, ANOWH D MIRAAA NRIYMICA tHW ITOUNC' 5 GAL. 3' OG 6 10 D V' D YELLOW TLIG CGRWO ST0.WRERA FLAVIRAMEA 5 GAL. 3' OL LG NONETtlICKLE, EMERALD MONO LOWICERA XTLOOTEIM CGTTACTA D GAL 4' OZ. RIp yry W PEgypR(LE' NY' VMCA MINOR 2y POTS 2- Oc M1LAMJ 0 ,RT RILroERNG 2y Trott n• Oc PERENNIALS IRAM) WW m ccZ�OpI o] N0 O moo M Q I.j O O u o z W F' s Lu W85 N J d w _ W W Z W 2 RR) ¢ V Z F VI ¢ a � V U ~ W ¢ VI � w a Q w H � O ■ AI®11111 Ll OLLlNER CERTIFICATION M YEIMYRo. s[Ne M LrRE N!R w M PawRRT Gitf' ®T i1R MR NM. wA. aRFT MMT IfOT M rR uO RYIRLTTwR rfi RF'M W 64P Mrt Fl/x WeR PM MRPYTRM4 K RNL 6�41T 4 11;WGL WWRA PAL PLANNING AND ZONING CERTIFICATION MOTm Ri M NRWI �O mYtl a :'o AY ATTORNEY CERTIFICATION uxF6 TO I,yT Tw1 Tw .w _ u MTTM1FTOM wRMLDAW AVD p.Y�rRo M ORa1R w 1Rcoo a rm PIUPRP- R VICINITY PLAN KG.c. , 1000 =1 IIDAAI DUPLEX Rml 0 — - - /( p1lIGIN roP T K0' RADIUS WEST EL Ijg W STREET - - �TIIA)bFORI SLIS STLf / LMIT OD' T oIie D. 1 ml • %� I I I I IAMOND TACO I A'110001d •!LL I I I I L— p'JI BP ZONlwx DISTRICT, -�` - El WDESK TED MA'ADCR PNCEL CB. POTTS •� — i Q 4 • Q `. EXISTFtl DEDICATED PARCMG 4 — " I ACCESS EASEPEIIT SITE DEVELOPMENT PLAN LeC.L%L DE5CRIPTION A RORTICN OF "HATADq¢ APAR S e1GDIVIeICN RIASE Iv IT. THE CIR OF Fd[T CCLL", C4IGRADO', LOCATED N T11E yyTllApT QE-yARTER OF WCTIQ 9, TC W alWr I NORM, lultl 6e Me?, OF TWE 6W Pn, LARIKR C JODLCllADO SITE DEVELOPMENT DATA LOT AEA 72,1131 OF (IN! AC) 111LDR6 FCOTPRNT AREA 0,512 OF }} t P.}ISCMG. W AND DRIVES }Tjmav EF 31 i LJI06CAPCp AMA5 alROu EF Al s ",pXIlAfI 1LILDRG WEIWT 26' E AS'IK ZW RH M14H DENSITY WaIDENT4 6 etTEET 10 R 141 ^FACESP VIDED 39 SPACES THE DE VELOpMENT U TAWS }} APART'ENT WITS. EKu WI' NAa } BEDINOI'Po AND IS }-STg FRA1E =GT'9'W+C'iCf1 THE (sROSS FLOOR AREA OF EACH WIT 6 "A N cLCOR 636 SG M FODT 2M cLQ 513 YJJAIE FCOT 'OT4 II49 ARE FDOT -WE'O'AL RESIDENTIAL DENSITY FOR THE ENTIRE oLD. (GRJSS) S24 WITS - 1665 ACRES• 13b DMLLJK W'TS F£R ACRE IDLPAI -:TFNERAL NOTES REIER -G _. _APE PLAN FOR ALL LASPCCAPNG n+PR')v£TEI.'5 AND RELATED NOTES. MPBt TO LAVDE P'LA4 FOR FENCMG DETAILS. i. RERR TO SITE DRAjN PLAN AND ORAI IEPCRT cOR P4RICRG LOT G 11*2 Alm D IkoXkE IIFCRIATICN AVD'CPPaRAPHIC DATA 3 NO DEvELOR T 1DENTRICATICN IS PIGPCEED PCR 'I+E PROJECT MISCELLA`E" TRARIC, DIRECTIONAL AND B.x_DING IDEMFICATION 51wACE WILL BE PROVIDED 4. !HE DEVELLq-IENT F ADWAY Af PARCMG AMAS ARE OWED AND TIAIMARED. 5. TLCJ } BBC'CLE PAWING AREAS AM PROVIDED FOR 'LE , TS JI'HOJT GARAGES. METAL BICYCLE 5TC4,:GE RACKB WILT BE PROVIDED. 6 'Rh91. CGL_ECTICN WILL BE BY A MVATE CCNTRACTGR N9'4 DEL IVERT SHALL BE TO IEIOWSC OVJ DEC rSRY 4 COLLECTION BOX WIM MDCCL. 5'E _ Gy: z WILL BE BY dIILDING MOMTED AND 'WE 5't LING FIXTUM6. SITUATED Alm DIRECTED SC A5 NG' Io CAUSE GLARE AT ADJACENT PROPERTIES. S A _ eARKIW, SPACES AT WITS WITHOUT GARAGES 5L,AL, BE 9' T BY IT FOOT SPACES. FAIR (4) WA ICAP 'PACES ARE FROVIDEO AT 13 EDDY BY n POOT. NO "o'OR.,C_E PARKING IS FlB P. GaED. a YWE ° , eA-EL' GUNEO NEE HNRANT AT TILE EAST �Wy LINE HAS BEEN INSTALLED AND MAINTAINED BY A D 'OR THE BENEFIT OF TIE MATA APARR'IENTS. 'L 5 FIRE L,TDRANT / THE 6" WATER LINE TO IT WALL BE RE110`!ED AND RE_OCAMP TO A POINT 5 FEET WITHIN YLE MA'ACO _vART"ENT5FROPER'Y. ANY LANDSCAPING CR.RNC NG J 5-_RBEG B- -LI5 L SLALL BE MPLACET yam! T IOIB� 5 ^.AWLETE THE POTTS' PJD, WILL LAVE -4D RESMI W LITKS LF WlIRbVT, MAMlGiA4CE. Q! ACCESS N RELATION TO TINS FM HYDRANT. 0 �� SL+ICLE OuMS WIICH D INS THE 24 FOOT TRAFFIC _ArvF SSA_ L BE PANTED RED. SIX SIffJS WIICH READ NO -AEKNG - YM LA,IE" WALL BE PRJVIDED AT _Oc4_ ONE 8410J WW 00 D� we 0 mO e o m e m � 0 V O 5 F d W J N F H Gi V J W � 2 Q N U V ~ W Q N V J O a a '•' • • �1�1"11 LEGEND1+33 • 2 I ndicetes Existing Surface Spot Elevation 21.3 Indicates Proposed Surface Spot Elevation ----23--- Indicates Existing Contour Line wi Elevation --- 23 Indicates Proposed Contour Lim w1 Elevation 23A66 ToC Indicates Proposed Top of Curb Elevation WDNDRI Indicates Existing Sub -Basin Limits Indicates Proposed Sub -Basin Limits QIndicates SuDBasm Designation A Area facial �— Indicates Flow Direction 4� Indicates Point of Concentralion NORTH� 0 er_ALE 0 , r . w e Pry 30 45 60 � j N, W_IT Ol5 Minimum DRAINAGE SWALE TYPICAL SECTION al4o-Scala ("TYPICAL" for"A-Ae & "B-B") NOTE that the location of 'Swale' towline may vary horizontally in order to avoid conflict with landscape plantings. AR A2 i A5 a - �� r— _ °'.E4595 42 �Y 142. PNPO° \ \ 4, 'A SWATS, _ "F" At p / 6TOfIMWATER DETENTION S1 AM REOI1aDK .lm7mR REWIRED tOILE.1}pa.11. a.W LpIRSF - ciww a PV W 'gLLRfE . a0pm t R IN L.4110 H. W L.31.15 �I SIPF.ICE AREAOHWL.IIO5A A 3IKALEA1EAeHWL.116 X. PEAK snwr . o .os u.L FLAX DScl..lr.. o .ON °tA NOS Tr wsm.�aPma,i, a.HmwSmeaie A In _VWaamee 1 I aMwialmw3MP.T NITR-P Ian.mb5vbaaeawea .� ref APaweY ro.a lr inuw MLya Put ralsa,cam.ee ToolArta. Ia/Se anai4. 1721 gOaY1e . 3 A t aal Row l-C NnUr. 0 No OniY. to AS a OAR ec r a is a 1. to a, Maim, OnaiYron,m (I cu. 0w.I%L1. Oaaim Rewa. Va.lm,fA ciri cra. TWRem.R O..LWefA Oie.AtB eft /E 167 a' PIA p ATg pRAAi OmWIMafWDLagw_ — e•eo — mulAm= IOR:ama oiwu.o.SESe,ti gaim.aatana runmml'C forth, 0ex a's Omit note, ao At.l. lose. 00.15M w E%lei MYYCLR/AB£ Qinm Runts ya.Mlas. SRI 9"aF IM9 EL[V.]A'b G nY Powa: Q'.lfera. gr. LMt[a .•SE"W TnWRLWO gL.Waa Qw. Hlocra 45 AmmAiuem NOn�useemmYdatallm Rtllitran Flapua Meeting 'amnmaBytl nh JemyavWratsaEmum AiNaara mN4 D Se, tf a. taN Mama Y witty Mbyulayy M RllTa - POD MAI T.a3 mRa'Aaflw Yrl.P`eaMMmW Ae.eem.ulxa+em Rs w>Y•su 4P^`Nw1 dfa wiNu t6mADMC. N. a MYp�tiq W INt a IOYA immiAawrm W eenb> W eY. TletYal.tlua Mqa mmMe.e rorre.Pu D .ee um c. e • romA o-�tim a i. m u. m�mmm eFl,EAO n,. rt. gM�Bapp$apllpy C�v aN6 fLYelAr: A. �tA� fs ANe, Am Ratiul Y'«'PNa. 'f�.�m cW pdeOen V}.�AcIAt. O6i1e MYed_3glLcf/at- Pi6itu Lou 0ti;` �� .a y NOTE: The High Water Elevation for the on -site detention area is II GENERAL NOTES. . 1. Place *Area Inlet Filter Straw Bales' immediately after the Area Inlet has Dean constructed and the surface SurroureciN the Inlet has bean brought to subgrade. Remove In Order to Place paving and replace following paving operations. The 'Filter' is M remain in place until Slab time as the site _ landscaping is 50 > Complete. s 2. Place'Straw Bale Dike Chancel Applica6on'immendately after the site 6 grading has Dean Performed and any utilities that are to be placed along the as 5terty property line are in pace. I Me S raw HaieS are t0 remain in place 0 - -until So l time as the Portion of the Ianclospirg m lg the 6asteny pmperry j line IS100ee complete. 3. Upon Completion and acce0tance of the drainage fac obits indicat hereon the main n of an drainage facilities associated 1 AI this tlev oprmnt i� rm t responsibility of the City of Fot C Iliny Storm L�--00)MW Os-04pcls all Can -I At e all t � =SyVt g! j Tzi T P Of q 0 DRAINAGE SWALE• n-a8N-1Ba 3Z Dm Do AZ Um e ' r U;d 2.39cN all L`~ Ear s w \ euleTwa iwauL p TM Or r ev aY Tr eIYNE 40 Gram = •O. MXG,YLfQ Or =AR10 d .0.3 - 109% aG'e 3516±1n'v& Co_ wl 4 n T PEODL 303 _7 /mNWwH-G-3l3I.. . rfL.33/S 5 q 3 It _ IVNIOLE OrRR qAM a iQR Ne•NWTt uELT naraoLe A.I F'RIVgT- ADS G]3� INLAND UPSTREAM MAIN 90II.ATTRAL. WITH DEFLECTOR DIRECTLY OPPOSED LATERAL WITH DEFLECTOR MAD LOSSES ARE STILL 9RC96SIVE 9SWlAICAATLT LESS I'll "IN FOR MANHOLES COY OF FOR COLLINS. COLORADO 0 0 i O O « L A vrW «•^•w• 1° A �7149L t,. t �;.._ -_ y Orr C- SE. _ c semlox A -A SECTION re, • • • ` , O nI ...ANY n.vA rCRu na arc ""-""'°^ CITY Or PoAi 0 f. COLORADO Potion Plata Or«Iy Over Is- 0e Dona Pipe with Ortlm Charing at the Invert of the Pon S ud BDIn Samnrq Pairsto Inbt Wal tq' Stml Plate MPICAQ 2W Omeas owmi„_ " 1 Itr I T ur ORIFICE PLATE DEAIL Mitt scale ANDAGn4 0 LIC! - - Ex13 lN0- R TIN,;•, J/) z-e ^I°. outrOil Pi Pee It= Oa• 1.29cfs o a SICIIIfo k 41040NAT ILL+'aw Q°if 4.66 cis I Yl. e7C•N.r 0 wow Y Photo 4 A w >rwealAe m at a N .�w..rr.... J r ARfA WIETI Z _ _ w STMW aA N .. �fFr ar��f mun 1vElOMw: C ; • L v In — . o N I I �'i'�.. In 0. W1� v4.LINDA" -Ruder Coal 1RANNQeIR � Aw1m r~jOj SO Thru EA ng Parking Wls to Nam and WHINk MIN Foil, as par existing conditcn. - ®® aPmammaaiaaWY,i LAW eH 1 A..Wrvt fr A� 1�'t STRAW BALE m«rr CHANNEL APPLI DOL AR «n.««..w..., Pry a roe IA on % ei NA C 12 O C m O,. C U Q Oi E o 0 UCJ m C N 5 :III W CLIENT APPROVAL BY DATE 0 Z O 0 0 z OoOO VIpQ i &iU 1 adz UJIpJ ti ` aa0 ILI Z IN 0 � W O t] LL 4 O L, Z 1 L] AMC S 43 O 2 PIA-071- SHEET 4 of STORM DRAIN PROFILE