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HomeMy WebLinkAboutDrainage Reports - 01/13/1998I 1 1 1 1 1 1 1 1 I�1 1 1 1 1 Nnad Approved Report DRAINAGE INVESTIGATION FOR MYRTLE STREET VILLAGE APARTMENTS TO BE LOCATED ON LOT 7 AND THE NORTH HALF OF LOT 89 BLOCK 106 OF I ARRISON'S ADDITION TO THE CITY OF FORT COLLINS, LARIMER COUNTY, COLORADO Prepared for Rocky Mountain C - M, Inc. P. O. Box 9555 Fort Collin.., Colorado 80525 March 1997 Project No. GRD - 241- 97 (Revised: November 25, 1997) W1900M I8 Enaineerh g Assockrtes 150 E. 29th Street, #238 Loveland, Colorado 80538 Iblephone: (970) 663 - 2221 I 1 11 I November 25, 1997 Project No. GRD - 241- 97 Mr. Basil Y. Hamdan Stormwater Utility 235 Mathews P..O. Box 580 Fort Collins, Colorado 80522-0580 Dear Mr. Hamdan, The enclosed report represents the results of the drainage investigation for a proposed apartment complex to be located on Lot 7 and the North Half of Lot 8, Block 106 of "Harrisoes Addition" to 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. If you should have any questions, please feel free to contact this office. Respectfully Submitted, MESS R Engineering Associates Dennis R. Messner, P.E. ' DRM/mkm ' Enclosures ce: Rocky Mountain C - M, Inc. Civil and Environmental Engineering Consultants ' 150 E. 29th Street, Suite 238 Loveland, Colorado 80538 Telephone: (970) 663-2221 TABLE -OF CONTENTS Letter of Transmittal , Table of Contents Scope Site Description "Historic" Conditions Proposed Development Erosion Control Measures Conclusions and Recommendations References Drainage Summary Erosion Control Cost Estimate letter EXHIBITS Vicinity Map Existing Conditions Exhibit Proposed Conditions Exhibit Proposed Grading and Drainage Plans Calculations ii i ii 1 1 1 2 2 4 4 SCOPE The following report represents the results of a drainage investigation for a proposed apartment complex to be located in the * Northeast Quarter of Section 14, Township 7 North,_ Range 69 West of the 6th RM.in the City. of Fort Collins, Larimer County, Colorado. The investigation was performed for the project manager, Rocky Mountain C - M, Inc. 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 the. 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 building 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. The site is rectangular and contains approximately 1.15 acres with one-half of the adjacent streets and alley considered. The site's East-West dimension is approximately 250 feet (190 feet without one-half of the adjacent street and alley.), and its North -South dimension is approximately 200 feet (150 feet without one-half of the adjacent street and alley). The site abuts the easterly right-of-way of Howes Street, the southerly right-of- way of Myrtle Street and the easterly right-of-way of the alley. The site is located in the OLD TOWN DRAINAGE BASIN. "HISTORIC" CONDITIONS The' site is a well established residential area and is surrounded by streets, alley and existing residential, commercial and professional office uses. The site contains five (5) residential structures. The site's ground surface slopes are considered to be extremely flat and range from 0.4% to 0.6%. The "historic" direction that the site slopes is from South to North toward Myrtle Street. The site does not have well established and readily definable drainage patterns: For the purposes of this investigation, five separate basins have been considered for the site. The basins coincide with the basins determined for the site after the site is redeveloped. The area to the South of the site is residential in nature. The rear yards and the rear portion of the structures for one and one=half lot to the South have been considered to contribute to the drainage on site. The area in the front yards and the front portion for the structures have been considered to drain to the North and West to a storm drain inlet located at the East side of the Southeast corner of the intersection of Howes Street and Myrtle Street. The area in the front yards and the front portion for the structures have been considered to drain to the North and East to the curb and gutter in Myrtle Street at the North side of the site. The run-off that accumulates in the gutter flows easterly to the corner of Myrtle Street and Mason Street. The run-off flows into a storm drain inlet at this intersection. The alley located at the East side of the site drains from South to North. The alley has a minor cross 1 slope from East to West. 1 1 All of the run-off from. the site and the offsite area that drains onto the site is directed into the storm drain that is located in Myrtle Street. The storm drain in the block ' between Howes and Mason Street is a 24 inch diameter concrete pipe. The storm drain flows easterly and northerly through the "Old Town" area until it discharges into the Cache .La Poudre River. ••eI . 1 1 MMUTVD ' The proposed redevelopment of the site is- to consist of the removal of the three structures located along Myrtle Street. The two structures at the southerly limits of the site that face Howes Street are*to be retained. Three four unit apartment structures are ' to be constructed along Myrtle Street. ' A duplex structure and parking lots are to be constructed along the alley and at the central rear portion of the property. As previously stated the run-off from the site flows to Howes Street and Myrtle Street. The street improvements and the storm drain situated in Myrtle Street are the only drainage facilities available to accept run-off from the site. ' The City policy established in the "Old Town Basin Master Drainage Plan" allows for properties to be redeveloped with 60 per cent of the site as impervious surface before on - site detention is required. The site and the adjacent streets and alley have been ' estimated to be 64 per cent impervious following redevelopment of the site. Therefore, on -site detention is to be provided. ' The City's policies normally require that the adjacent streetflows be incorporated with the onsite detention requirements. This policy applies most efficiently when the street construction and onsite detention are performed concurrently. In this instance, it is ' not physically feasible to combine the two flows since the flow generated on the streets can not be intercepted and directed into an on -site detention facility and then routed back into the curb and gutter. Due to existing physical constraint's, that is, the ' - — extremely flat topography of the site and surrounding block, the areas within the _easterly half of the Howes Street right-of-way, the southerly half of the Myrtle Street right-of-way and the westerly,half of the alley have not been considered as tributary to ' the detention: facilities for sizing purposes. The proposed detention facilities are to be located at the east central portion of the site in the proposed parking lots. The detention facilities,.will outfall through a storm drain pipe that connects with the existing 24 inch diameter storm. drain in Myrtle Street. ' EROSION CONTROL MEASURES ' Erosion control considerations are based upon the short term activities that occur during construction and the long term measures that are to be placed for the life of the facility. The long term measures are the proposed methods and materials to be used to ' provide surface treatments for the driveways, parking areas, walkways and the landscape materials and. plantings in the.open areas that will provide a combination of ground covers to deter erosion. . .2 1 The anticipated construction schedule should have the site grading completed, within one (1) week after commencing construction. The time frame for construction activities ' is. anticipated to be: initial week to perform site grading; second and third week required to construct drainage related facilities; third and fourth week to construct building foundations and install water and sewer service lines; fifth through eleventh ' weeks construct structure; twelfth .week ' construct curb, gutter and sidewalks;thirteenth week place pavement; twelfth through fourteenth weeks install landscaping. ' The recommended short' term erosion control methods to be incorporated with the construction activities consist of the following: prior. to commencing construction a "Silt Fence" is to be placed along the western, northern and eastern boundary of the site in order to control and contain mud and debris onsite; upon completion of grading operations and at the time that the drainage inlets are installed a "Straw Bale Filter" is ' to be placed at each inlet; and tracked mud to be cleaned up as required. Wind erosion measures are to consist of water application and roughening of exposed surfaces. 1 1 t 1 3 ' C'ONCLUSIONS AND RECOMMENDATIONS ' 1. The proposed development will retain the "historic" drainage patterns. ' 2. The. site is located in the, OLD TOWN DRAINAGE BASIN. The site is not located within a defined floodway or flood plain. 3. All development is to be performed in accordance with City of Fort Collins criteria. A variance to the City's policies is requested from detention of adjacent street flows due to physical impracticality. 4. Onsite detention of storm water is required since the site will exceed 60 per cent impervious area upon redevelopment. The volume of run-off to be detained estimated per the criteria is 4,482 cubic feet. The detention volume to be provided ' is 2,675 cubic feet. The volume generated from the tributary area is to be released at a controlled rate to maximize the available storage volume. The calculated release rate from the detention basin is 0.25 c.f.s. 5. The City of Fort Collins Standards for temporary erosion control measures are to be incorporated with the construction activities. Specifically, the ' following are to be incorporated in the site construction activities: a. A "Silt Fence" is to be placed along the easterly border of the site. ' b. "Straw Bale Filters" are to be placed at each inlet. ' c. Water application is to be made to prevent dust during the site development phase of the project. ' d. Roughening of the exposed earth surfaces shall take place during the site development phase of the project. ' REFERENCES ' 1. City of Fort Collins, STORM DRAINAGE DESIGN CRITERIA AND CONSTRUCTION STANDARDS, May 1984 with subsequent revisions and additions. ' 2. OLD TOWN BASIN MASTER DRAINAGE., prepared by Resource Consultants and Engineers, Fort Collins, Colorado, January 7, 1993. t 4 I 1 1 1 1 STORM WATER DETEN7.'ION SUMMARY SITE DRAINS TO "OLD TOWN' DRAINAGE BASIN GROSS SITE AREA (including adjacent streets & alley) = 50,000 Sq. Ft. = 1.15 Ac. ± NET SITE AREA = 28,500 Sq.Ft. = 0.654 Ac. ± HISTORIC "C" = 0.52 DEVELOPED "C" = 0.69 HISTORIC "Q2" = 1.26 c1s. CRITERIA BASED DETENTION VOLUME = 4,482 Cu.Ft. ± PLAN DETENTION VOLUME = 2,675 Cu.Ft. MAXIMUM DEPTH OF DETAINED WATER = 1.2 Ft. ® High Water Elevation 4995.40 PEAK DISCHARGE FROM DETENTION, Q = 0.25 c1s. . ' Engineering Associates November 25, 1997 Project No. GRD - 241- 97 ' Mr. Basil Hamdan ' Stormwater Utility City of Fort Collins 235 Mathews P. 0. Box 580 ' Fort Collins, Colorado 80522 - 0580 ' Re: Myrtle Street Village Apartments, Fort Collins, Colorado Dear Mr. Hamdan, ' The estimated cost for erosion control devices for the subject site has been estimated to be: ' 1. Silt Fence 3301.f. @ $2.50/ft. _ $ 825.00 2.. Straw Bale Filter 2 Each @ $150.00/Ea. = 300.00 ' Total $1,125.00 Cost @ 150% = 1.5 x $1,125.00 = $1,687.50 ' The cost to re -seed the 21,376 square foot site at $0.0298/sq.ft. _ $637.00 ' 150% of the re -seeding cost =1.5 x $637.00 = $955.50 Therefore, the subject project's estimated erosion control security amount is ' determined to be $1,687.50. This amount is to be included as surety for the erosion control guarantee along with any other surety requirements that may be a part of the City's "Developer's Agreement" requirements. ' If you should have any questions or desire additional information, please feel free to contact this office. Respectfully Submitted, MESS R Engineering Associates �ApO R � c ' J ` ;109 i : Q Dennis R. Messner, P.E. cc: Rocky Mountain C-M, Inc. ''��i�cS'/'e°° ���'o !i o ppw���� 1 Civil and Environmental Engineering Consultants 150 E. 29th Street, Suite 238 Loveland, Colorado 80538 Telephone: (970) 663-2221 LE U Poo � Ul P E VICINTY MAP (Not -to -Scale) Mo W. untain Avr I E. Mountain Avg k St E Oak St. � I E Olive St. u > > a u a a E a u = N E V1 N u I u E Magnolia St c at` v 0 0. 3 cD J Z.° \ M Vj s Ln ul v I Vi E Mulberry S N N LA V7 w. M rtte St I r Myrtle S a i `� V' SITE E. Laurel St S t / e Q, cr p E Plum St ., Old ain > (Soto a Dr Locust St. E. Elizabeth c o ers'it „ u � p U n i v Avc3 — Garfield u > Sout� Dr 'a ` p I c �o , �' ,;, Edwards c VICINTY MAP for PROPOSED APARTMENT COMPLEX TO BE LOCATED AT HOWES STREET AND MYRTLE STREET FORT COLLINS, COLORADO Property Description: All of Lot 7 and the North Half of Lot 8, Block 106 of'Harrison's Addition," Fort Collins, Colorado 1 1 1 1 1 1 1 1 1 1 1 1 M J� I I 95 / �945- i��r= ��/L&L-----/ff---��--�/---r_-i/L. #-ice- -------- ---- '- a a i �7 7 % I �- / :�-�------------------------I- - - - - - - - - - - - - - - - ` Existing 1J #5 I ( Inlet I I�. II 4 r _J L--11 1 \� 1 1 I 5 3 4 Roof Drain - - - - - - m 1 s.o q+ I I Existing House 'o I I I I I I Existing House i i ��,9 I Existing 1 I I ( 1 I I Office Building -_J L_ ------- L-_____� 2 L--- 4 _�93.30 r_ Existing 95.901 � 93.30----�`96.20 Ho a i- J n` Roof Drain 6. II I I I / rJ a II I / �• "'�98_ U # -� \� 95.90 �X95.70 II - - - - - - - i ( I --I ---- �T 1 ----�I-4 I� I \ - /-- \ u 95.70b1,y III I Exists g House I I I I h �1----------J J Existing t-� Garage pp p I I I I--r----- OFFSITE I 19s.2e II UU I Exi tmg I I 4 I I I R I I I (� i Gaage i I 96.35 1-� J Exists House I QI �._=6=►* 96.50 b p E 196.11 _ _ _ _ i I 96.30 i96.30 96.30 _� 96.30 , 96.20 �96,54 0 15 60 1"=30' Contour Interval: 0.5' Basin Designation Area (acres) Rational 'C' Q2 (c.f.s.) Q100 (C.f.S.) OFFSITE 0.18 0.30 0.10 0.35 # 1 0.20 0.29 0.20 0.72 #2 0.18 0.30 0.14 0.49 #3 0.34 0.61 0.52 1.88 #4 0.31 0.73 0.57 2.05 #5 0.13 0.49, 0.16 0.58 N N N �o v � � c m m o U � a, m M o m N � C_ O U O c � w of m J g E m p' O o N 7L a W N rn L m _ > t � C U N w w LO z z z!� z U (D W 00 �o Z� w w J V FJ- H DATE: NOV.26.1997 SCALE: 1•=20' DRAWN: M,S.R, CHKD: D.R.M Project No. GRD-241-97 SHEET 1 of 2. I I 1 ��--ML4r Ate scat b 7 I7 - a--� vrr�ii� � I I I I Q � � � I 91 4 96. I I y� �• �a� T 96.50 9 96.30 96.30 r96.20 P P 15.30 --- 4 Roof Drain Existing Office Building 93.30 r _ I I II 93.30 I �-------� 96.20 Roof Drain 96.05� bn -� 95.70 N 95.701,E 0 15 60 1' = 30' Contour Interval: 0.5' * NOTE: Alley grading and drainage to retain the pattern established prior to redevelopment of this site. Basin Designation Area (acres) Rational 'C' Q2 (C.f.s.) Q100 (C.f.s.) OFFSITE 0.18 0.30 0.10 0.35 #1 0.20 0.54 0.51 1.86 #2 0.18 0.75 0.34 1.22 #3 0.34 0.62 0.53 1.91 #4 0.31 0!77 0.60 2.16 #5 0.13 0.54 0.18 1- 0.64 RNA U zC) w U U w H U N N co 0 LO 17 0 00 U L C 0 J C6 M N VI rn N la1 DATE NOV.26.1997 SCALE: 1-=20' DRAWN: M.S.R. CHKD: D.R.M Project No. GRD-241-97 SHEET 2 of 2 I I 1 1 C ' ° IIT C ��y , 'llT,C :Ho I I I I 11 I I I I I [1 I I [1 DRAINAGE INVESTIGATION CALCULATIONS t 1 1 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 112 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 This investigation is being performed to determine the required detention volume, discharge rates, and structure sizing for the subject project site. The site is located in the "OLD TOWN" Drainage Basin. RATIONAL METHOD Runoff Coefficients, "C" City of Fort Collins S.D.D.C.&C.S. (Table 3-3) Land Use Description "C" Building/Roofs 0.95 Drives and Walks 0.95 Gravel Surfaced 0.50 Undeveloped n Areas 0.20 Grassed Landscaped Areas 0.15 EXISTING CONDITIONS: RATIONAL METHOD Frequency Adjustment Factors Storm Return Period ears Freq. Factor "Cf' 2 1.00 5 1.00 10 1.00 100 1.25 ' Consider site as one drainage basin with half of adjacent streets included. Building/Roof Area= 6,580 Sq.Ft. ' Street, Drives and Walks Area= 16,595 Sq.FL (includes adj. Alley, Howes & Myrtle) Gravel Surfaced Landscape Area= 0 Sq.Ft. Undeveloped Open Areas Area= 0 Sq.Ft. Landscaped Areas Area= 26,825 Sq.Ft. TOTAL SITE AREA Area= 50,000 Sq.Ft. = 1.15 Acres ' Avg. C = [(0.95 x 6,850)+(0.95 X 16,595)+(0.15 x 26,825)] + 50,000 = 0.52 C2 = C X Cf = 0.52 x 1.00 = 0.52 ' C5 = C X Cf = 0.52 x 1.00= 0.52 ' C10=CXCf=0.52x1.00= 0.52 C100 = C X Cf = 0.52 x 1.25 = 0.65 NOTE: If the site is considered in the totally undeveloped state C = 0.20 (Unimproved Areas) per Table 3-2 of the City's 'Criteria Manual'. ' Page 1 of 18 t DRAINAGE INVESTIGATION CALCULATIONS ' Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Dare: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. 1 Revised: Nov. 25, 1997 EXISTING CONDITIONS: (cont.) ' Time of Concentration Consider sheet flow across site from Southwest to Northeast at rear of houses to remain. 1 - 4995.6 0.60 ft. L = 140 ft. Elev. Diff. 4996.2 = ' Slope, S = 0.43 % T = 1.87(1.1-CC04L+(SAl/3)=1.87(1.1-(0.52x1.00))4140+( 0.43A1/3) = 17.00 Minutes ' Since surrounding area is developed consider for 'urbanized' condition as a check Tc = L / 180+ 10 for'urbanized' condition with longest flow path considered ' Length, L = 210 ft. Tc = 210 / 180 + 10 = 11.17 minutes ' Average of the two methods = (17.00 + 11.17) / 2 = 14.09 minutes USE Te = 15 minutes since area is to have more dense development ' Rainfall Intensities based upon 15 minute Time of Concentration: 12 = 2.10 in./hr. I5 = 3.00. in./hr. ' I10 = 3.70 in./hr. I100 = 6.00 in./hr. Determine Run-off from Site and adjacent Street under present conditions: ' Q = CIACf Q2 = 0.52 x 2.10 x 1.15 x 1.00 = 1.26 c.f.s. Q5 = 0.52 x 3.00 x 1.15 x 1.00 = 1.79 c.f.s. ' Q10 = 0.52 x 3.70 x 1.15 x 1.00 = 2.21 c.f.s. Q100 = 0.52 x 6.00 x 1.15 x 1.25 = 3.59 c.f.s. Offsite Run-off @ Existing Conditions: The area in which the site is located is extremely flat with poorly defined drainage patterns. The general direction ' of surface run-off is from South to North. The lots to the South of the site have been considered to drain onto the site and through the rear yard . ' Flow Path, L = 100 Feet Offsite Area = 0.18 acre Cavg. _ [(1,348 x 0.95) + (216 x 0.95) + ( 6,636 x 0.15)] + 8,200 = 0.30 Page 2 of 18 DRAINAGE INVESTIGATION CALCULATIONS . Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 EXISTING CONDITIONS OFFS= AREA CONTRIBUTING TO SITE FROM THE SOUTH: (cont.) T = 1.87(1.1-CC04L+{SAl/3)=1.87(1.1-(0.30xl.00))4100+( 0.5A1/3) = 18.6 minutes Rainfall Intensities based upon 20 minute Time of Concentration: I2 = 1.85 in./hr. I5 = 2.65 in./hr. I10 = 3.25 in./hr. I100 = _ 5.20 in./hr. Q = CIACf Q2 = 0.31 x 1.85 x 0.18 x 1.00 = 0.10 c.f.s. Q5 = 0.31 x 2.65 x 0.18 x 1.00 = 0.14 c.f.s. Q10 = 0.31 x 3.25 x 0.18 x 1.00 = 0.18 c.f.s. Q100 = 0.31 x 5.20 x 0.18 x 1.25 = 0.35 c.f.s. EXISTING CONDITIONS FOR ONSITE AND OFFSITE AREA DRAINING TO SOUTH BASIN: (Basin #1) Area considered to be from the southernmost house that is two houses to the south of the site. Building/Roof Area 2,744 Sq.Ft. Drives and Walks Gravel Surfaced Landscape Area= 187 Sq.Ft. Area= 0 Sq.Ft. Undeveloped Open Areas Area = 0 Sq.Ft. Sq.Ft. Landscaped Areas Area= 13,475 ' TOTAL AREA Area= 16,406 Sq.Ft. = 0.38 Acres Avg. C = [(0.95 x 2,744)+(0.95 x 187)+(0.15 x 13,475)] + 16,406 = 0.29 ' Flow path considered to be from rear of southernmost house directed northeasterly to proposed parking lot. Flow considered to be 'overland', therefore, Tc = 1.87 (1.1 - CCf) AIL + SA 1/3 ' % Length, L 130 feet Slope, S = 0.5 = ' Tc = 1.87 (1.1-(0.29 x 1.00)) 4100 +0.5A1/3 = 21.75 minutes USE Tc = 20 minutes ' I2 = 1.85 in./hr. I5 = 2.65 in./hr. I10 = 3.25 in./hr. I100 = 5.20 in./hr. ' Page 3 of 18 1 DRAINAGE INVESTIGATION CALCULATIONS Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 ' Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. I Revised: Nov. 25, 1997 EXISTING CONDITIONS FOR ONSITE AND OFFSITE AREA DRAINING TO SOUTH BASIN: (cons.) tQ = CIACf Q2 = 0.29 x 1.85 x 0.38 x 1.00 = 0.20 c.f.s. ' Q5 = 0.29 x 2.65 x 0.38 x 1.00 = 0.29 c.f.s. Q10 = 0.29 x 3.25 x 0.38 x 1.00 = 0.36 c.f.s. ' Q100 = 0.29 x 5.20 x 0.38 x 1.25 = 0.72 c.f.s. EXISTING CONDITIONS FOR ONSITE AREA DRAINING TO NORTH BASIN: (Basin #2) ' Area considered to be rear yard and one half of the surrounding houses. Building/Roof Area= 1,360 Sq.Ft. ' Drives and Walks Area= 100 Sq.Ft. ' Gravel Surfaced Landscape Area= 0 Sq.Ft. Undeveloped Open Areas Area= 0 Sq.Ft. ' Landscaped Areas Area= 6,236 Sq.Ft. TOTAL AREA Area= 7,696 Sq.Ft. = 0.18 Acres ' C 1,360)+(0.95 100)+(0.15 6,236)) + 7,696 = 0.30 Avg. = ((0.95 x x x Flow path considered to be from rear of western house directed easterly to proposed parking lot. Flow considered to be 'overland', therefore, Tc = 1.87 (1.1 - CCf) AIL + SA 1/3 ' Slope, S = 0.5 % Length, L = 50 feet Tc = 1.87 (1.1-(0.30 x 1.00)) 4100 + 0.5A1/3 = 13.32 minutes ' USE Tc = 10 minutes I2 = 2.50 in./hr. I5 = 3.65 in./hr. ' I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.30 x 2.50 x 0.18 x 1.00 = 0.14 c.f.s. Q5 = 0.30 x 3.65 x 0.18 x 1.00 = 0.20 c.f.s. ' Q10 = 0.30 x 4.40 x 0.18 x 1.00 = 0.24 c.f.s. _ Q100 = 0.30 x 7.25 x 0.18 x 1.25 = 0.49 c.f.s. Page 4 of 18 DRAINAGE INVESTIGATION CALCULATIONS [1 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 EXISTING CONDITIONS FOR ONSITE AREA DRAINING TO HOWES STREET: (Basin #3) Area considered to be front half of houses, front yards and the east half of Howes Street. Building/Roof Drives and Walks Gravel Surfaced Landscape Undeveloped Open Areas Landscaped Areas Area= 2,000 Sq.Ft. Area= 6,520 Sq.Ft. Area= 0 Sq.Ft. Area= 0 Sq.Ft. Area= 6,280 Sq.Ft. TOTAL SITE AREA Area= 14,800 Sq.Ft. = 0.34 Acres Avg. C = [(0.95 x 2,000)+(0.95 x 6,520)+(0.15 x 6,280)] + 14,800 = 0.61 Flow path considered to be from front of southern house directed westerly to street and then along gutter to north. Flow considered to be 'channelized', therefore, Tc = Ti + T 1 Ti = 1.87 (1.1 - CCf) 4L + SAl/3 T1= Length of Flow Path / Velocity of Concentrated Flow Slope, S = 0.5 % Length, L = 45 feet Ti = 1.87 (1.1-(0.61 x 1.00)) 445 + MAW = 7.74 minutes Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 135 feet T1= L / (Vel. x 60 sec./min.) = 135 / (1.50 x 60) = 1.50 minutes Tc = Ti + T1 = 7.74 + 1.50 = 9.24 minutes USE Tc = 10 minutes 12 = 2.50 in./hr. I5 = 3.65 in./hr. I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.61 x 2.50 x 0.34 x 1.00 = 0.52 c.f.s. Q5 = 0.61 x 3.65 x 0.34 x 1.00 = 0.76 c.f.s. Q10 = 0.61 x 4.40 x 0.34 x 1.00 = 0.91 c.f.s. Q100 = 0.61 x 57.25 x 0.34 x 1.25 = 1.88 c.f.s. Page 5 of 18 1 I DRAINAGE INVESTIGATION CALCULATIONS 0 t 11 n t [1 1 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov.25, 1997 EXISTING CONDITIONS*FOR ONSITE AREA DRAINING TO MYRTLE STREET: (Basin #4) Area considered to be front half of houses, front yards and the south half of Myrtle Street. Building/Roof Area= 1,090 Sq.Ft. Drives and Walks Area= 8,695 Sq.Ft. Gravel Surfaced Landscape Area= 0 Sq.Ft. Undeveloped Open Areas Area = 0 Sq.Ft. L.andwapedAreas Area= 3,675 Sq.Ft. TOTAL AREA Alm = 13,460 Sq.Ft. = 0.31 Acres Avg. C = [(0.95 x 1,090)+(0.95 x 8,695)+(0.15 x 3,675)] + 13,460 = 0.73 Flow path considered to be from front of western house directed northerly to street and then along gutter to east. Flow considered to be 'channelized', therefore, Tc = Ti + T I Ti = 1.87 (1.1 - CCf) AIL + SAl/3 TI = Length of Flow Path / Velocity of Concentrated Flow Slope, S = 0.5 % Length, L = 30 feet Ti = 1.87 (1.1-(0.73 x 1.00)) 430 + 0.5A1/3 = 4.77 minutes Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 150 feet Tl = L / (Vel. x 60 sec./min.) = 150 / (1.50 x 60) = 1.67 minutes Tc = Ti + T1= 4.77 + 1.67 = 6.44 minutes USE Tc = 10 minutes 12 = 2.50 in./hr. I5 = 3.65 in./hr. I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.73 x 2.5 x 0.31 x 1.00 = 0.57 c.f.s. Q5 = 0.73 x 3.65 x 0.31 x 1.00 = 0.83 c.f.s. Q10 = 0.73 x 4.40 x 0.31 x 1.00 = 1.00 c.f.s. Q100 = 0.73 x 7.25 x 0.31 x 1.25 = 2.05 c.f.s. Page 6 of 18 1 ' DRAINAGE INVESTIGATION CALCULATIONS Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 ' Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov.25, 1997 EXISTING CONDITIONS FOR ONSITE AREA DRAINING TO ALLEY: (Basin #5) ' Building/Roof Area= 510 Sq.Ft. Drives and Walks Area= 2,000 Sq.Ft. ' Gravel Surfaced Landscape Area= 0 Sq.Ft. ' Undeveloped Open Areas Area= 0 Sq.Ft. Landscaped Areas Area= 3,328 Sq.Ft. ' TOTAL SITE AREA Area= 5,838 Sq.Ft. = 0.13 Acres Avg. C = [(0.95 x 510)+(0.95 x 2,000)+(0.15 x 3,328)) + 5,838 = 0.49 Flow path considered to be from southeast comer of site directed northerly to street and then along gutter to east. Flow considered to be 'channelized', therefore, Tc = Ti + T 1 Flow Ti = 1.87 (1.1 - CCf) 4L + SAI/3 Tl = Length of Flow Path / Velocity of Concentrated Slope, S = 0.5 % Length, L = 20 feet Ti = 1.87 (1.1-(0.49 x 1.00)) J20 + 0.5A1/3 = 6.43 minutes ' Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 150 feet TT = L / (Vel. x 60 sec./min) = 150 / (1.50 x 60) = 1.67 minutes ' Tc = Ti + T1= 6.43 + 1.67 = 8.10 minutes ' USE Tc = 10 minutes 12 = 2.50 in./hr. I5 = 3.65 in./hr. ' I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIA& Q2 = 0.49 x 2.5 x 0.13 x 1.00 = 0.16 c.f.s. ' Q5 = 0.49 x 3.65 x 0.13 x 1.00 = 0.23 c.f.s. Q10 = 0.49 x 4.40 x 0.13 x 1.00 = 0.28 c.f.s. ' Q100 = 0.49 x 7.25 x 0.13 x 1.25 = 0.58 c.f.s. ' Page 7 of 18 1 DRAINAGE INVESTIGATION CALCULATIONS ' Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. ' Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR ONSITE AND OFFSITE AREA DRAINING TO SOUTH BASIN: (Basin#1). Area considered to be from the southernmost house that is two houses to the south of the site. Building/Roof Area= 2,216 Sq.Ft. Drives and Walks Area= 5,707 Sq.Ft. Gravel Surfaced Landscape Area= 0 Sq.Ft. ' Open Areas Area= 0 Sq.Ft. Undeveloped Landscaped Areas Area= 8,483 Sq.Ft. TOTAL AREA Area= 16,406 Sq.Ft. = 0.38 Acres Avg. C = [(0.95 x 2,7216)+(0.95 x 5,707)+(0.15 x 8,483)] + 16,406 = 0.54 Flow path considered to be from rear of southernmost house directed northeasterly to proposed parking lot. ' Flow considered to be 'overland', therefore, Tc = 1.87 (1.1 - CCf) 4L + SAJ/3 Slope, S = 1.00 % Length, L = 80 feet Tc = 1.87 (1.1-(0.54 x 1.00)) 480 -+ 1.00A1/3 = 9.37 minutes USE Tc = 10 minutes 12 = 2.50 in./hr. I5 = 3.65 in./hr. ' I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.54 x 2.50 x 0.38 x 1.00 = 0.51 c.f.s. 3.65 0.38 1.00 0.75 Q5 = 0.54 x x x = c.f.s. Q10 = 0.54 x 4.40 x 0.38 x 1.00 = 0.90 c.f.s. Q100 = 0.54 x 7.25 x 0.38 x 1.25 = 1.86 c.f.s. 1 Page 8 of 18 1 ' DRAINAGE INVESTIGATION CALCULATIONS ' Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR ONSITE AREA DRAINING TO NORTH BASIN: (Basin #2) Area considered to be rear yard and one half of the surrounding houses. Building/Roof Area= 2,714 Sq.Ft. ' Drives and Walks Area= 3,040 Sq.Ft. Gravel Surfaced Landscape Area= 0 Sq.Ft. ' Undeveloped Open Areas Area= 0 Sq.Ft. Landscaped Areas Area= 1,942 Sq.Ft. TOTAL AREA Area= 7,696 Sq.Ft. = 0.18 Acres Avg. C = [(0.95 x 2,714)+(0.95 x 3,040)+(0.15 x 1,942)] + 7,696 = 0.75 Flow path considered to be from rear of western house directed easterly to proposed parking lot. tFlow considered to be'overland', therefore, Tc = 1.87 (1.1 - CCf) qL + SAl/3 ' Slope, S = 0.5 % Length, L = 50 feet Tc = 1.87 (1.1-(0.30 x 1.00)) 4100+0.5A1/3 = 5.83 minutes . ' USE Tc = 10 minutes I2 = 2.50 in./hr. I5 = 3.65 in./hr. ' I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.75 x 2.50 x 0.18 x 1.00 = 0.34 c.f.s. ' Q5 = 0.75 x 3.65 x 0.18 x 1.00 = 0.49 c.f.s. ' Q10 = 0.75 x 4.40 x 0.18 x 1.00 = 0.59 c.f.s. Q100 = 0.75 x 7.25 x 0.18 x 1.25 = 1.22 c.f.s. Page 9 of 18 ' DRAINAGE INVESTIGATION CALCULATIONS Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 ' Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR ONSITE AREA DRAINING TO HOWES STREET: (Basin #3) Area considered to be front half of houses, front yards and the east half of Howes Street. Building/Roof Area= 2,105 Sq.Ft. ' Drives and Walks Area= 6,605 Sq.Ft. ' Gravel Surfaced Landscape Area= 0 Sq.Ft. Undeveloped Open Areas Area = 0 Sq.Ft. 1 Landscaped Areas Area= 6,090 Sq.Ft. TOTAL SITE AREA Area= 14,800 Sq.Ft. = 0.34 Acres Avg. C = ((0.95 x 2,000)+(0.95 x 6,520)+(0.15 x 6,280)] + 14,800 = 0.62 Flow path considered to be from front of southern house directed westerly to street and then along gutter to north. Flow considered to be 'channelized', therefore, Tc = Ti + T 1 Ti = 1.87 (1.1 - CCf) 4L + SAl/3 T1= Length of Flow Path / Velocity of Concentrated Flow Slope, S = 0.5 % Length, L = 45 feet Ti = 1.87 (1.1-(0.62 x 1.00)) 445 + MAW = 7.58 minutes Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 135 feet T1= L / (Vel. x 60 sec./min.) = 135 / (1.5 x 60) = 1.50 minutes Tc = Ti + T1= 7.58 + 1.50 = 9.08 minutes USE Tc = 10 minutes I2 = 2.50 in./hr. I10 = 4.40 in./hr. Q = CIACf t I5 = 3.65 in./hr. I100 = 7.25 in./hr. Q2 = 0.62 x 2.50 x 0.34 x 1.00 = 0.53 c.f.s. Q5 = 0.62 x 3.65 x 0.34 x 1.00 = 0.77 c.f.s. Q10 = 0.62 x 4.40 x 0.34 x 1.00 = 0.93 c.f.s. Q100 = 0.62 x 57.25 x 0.34 x 1.25 = 1.91 c.f.s. Page 10 of 18 DRAINAGE INVESTIGATION CALCULATIONS [_1 1 1 1 1 1 1 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR ONSITE AREA DRAINING TO MYRTLE STREET: (Basin #4) Area considered to be front half of houses, front yards and the south half of Myrtle Street. Building/Roof Area= 1,855 Sq.Ft. Drives and Walks Area= 8,500 Sq.Ft. Gravel Surfaced Landscape Area= 0 Sq.Ft. Undeveloped Open Areas Area= 0 Sq.Ft. Landscaped Areas Area= 3,105 Sq.Ft. TOTAL AREA Area= 13,460 Sq.Ft. = 0.31 Acres Avg. C = [(0.95 x 1,855)+(0.95 x 8,500)+(0.15 x 3,105)J + 13,460 = 0.77 Flow path considered to be from front of western house directed northerly to street and then along gutter to east. Flow considered to be 'channelized', therefore, Tc = Ti + T I Ti = 1.87 (1.1 - CCf) AIL + SAl/3 TI = Length of Flow Path / Velocityof Concentrated Flow Slope, S = 0.5 % Length, L; = 30 feet Ti = 1.87 (1.1-(0.77 x 1.00)) �30 + 0.5A1/3 = 4.26 minutes Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 150 feet T1= L / (Vel. x 60 sec./min.) = 150 / (1.50 x 60) = 1.67 minutes Tc = Ti + T1= 6.43 + 1.67 = 5.93 minutes USE Tc = 10 minutes 12 = 2.50 in./hr. I5 = 3.65 in./hr. I10 = 4.40 in./hr. I100 = 7.25 in./hr. Q = CIACf Q2 = 0.77 x 2.5 x 0.31 x 1.00 = 0.60 c.f.s. Q5 = 0.77 x 3.65 x 0.31 x 1.00 = 0.87 c.f.s. QIO = 0.77 x 4.40 x 0.31 x 1.00 = 1.05 c.f.s. Q100 = 0.77 x 7.25 x 0.31 x 1.25 = 2.16 c.f.s. Page 11 of 18 1 DRAINAGE INVESTIGATION CALCULATIONS I 1 11 [1 1 1 1 11 1 I Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR ONSITE AREA DRAINING TO ALLEY: (Basin #5) Building/Roof Area= 855 Sq.Ft. Drives and Walks Area= 2,000 Sq.Ft. Gravel Surfaced Landscape Area = 0 Sq.Ft. Undeveloped Open Areas Area = 0 Sq.Ft. Landscaped Areas Area= 2,983 Sq.Ft. TOTAL SITE AREA Area= 5,838 Sq.Ft. = 0.13 Acres Avg. C = ((0.95 x 855)+(0.95 x 2,000)+(0.15 x 2,983)] + 5,838 = 0.54 Flow path considered to be from southeast corner of site directed northerly to street and then along gutter to east. Flow considered to be 'channelized', therefore, Tc = Ti + T 1 Ti = 1.87 (1.1 - CCf) AIL + SAl/3 TI = Length of Flow Path / Velocity of Concentrated Flow Slope, S = 0.5 % Length, L = 20 feet Ti = 1.87 (1.1-(0.54 x 1.00)) 420 + 0.5A1/3 = 5.90 minutes Vel.( Fig. 3-2 U.D.F.C.D.) = 1.5 f.p.s. Length, L = 150 feet T1= L / (Vel. x 60 secJmin.) = 150 / (1.50 x 60) = 1.67 minutes Tc = Ti + Tl = 5.90 + 1.67 = 7.57 minutes USE Tc = 10 minutes I2 = 2.50 in./hr. I5 = 3.65 in./hr. I10 = 4.40 in./hr. II00 = 7.25 in./hr. Q = CIACf Q2 = 0.54 x 2.5 x 0.13 x 1.00 = 0.18 c.f.s. Q5 = 0.54 x 3.65 x 0.13 x 1.00 = 0.26 c.f.s. Q10 = 0.54 x 4.40 x 0.13 x 1.00= 0.31 c.f.s. Q100 = 0.54 x 7.25 x 0.13 x 1.25 = 0.64 c.f.s. Page 12 of 18 DRAINAGE INVESTIGATION CALCULATIONS i i Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov. 25, 1997 PROPOSED CONDITIONS FOR TOTAL SITE CONSIDERED AS ONE BASIN: % Impervious Building/Roof Area= 8,397 Sq.Ft. 90 Drives and Walks Area= 25,630 Sq.Ft. 96 Gravel Surfaced Landscape Area= 0 Sq.Ft. 13 Undeveloped Open Areas Area= 0 Sq.Ft. 45 Landscaped Areas Area= 15,973 Sq.Ft. 0 TOTAL SITE AREA Area= 50,000 Sq.Ft. = 1.15 Acres Avg. C = [(0.95 x 8,397)+(0.95 x 25,630)+(0.15 x 15,973)] + 50,000 = 0.69 Avg. % Impr. = [(90 x 8,397)+(96 x 25,630)+(0 x 15,973)] + 50,000 = 64.32 % USE Tc = 15 minutes (from Existing Conditions) I2 = 2.10 in./hr. I5 = 3.00 in./hr. I10 = 3.70 in./hr. I100 = 6.00 in./hr. Q = CIACf Q2 = 0.69 x 2.10x 1.15 x 1.00 = 1.67 c.f.s. Q5 = 0.69 x 3.00 x 1.15 x 1.00 = 2.38 c.f.s. Q10 = 0.69 x 3.70 x 1.15 x 1.00 = 2.94 c.f.s. Q100 = 0.69 x 6.00 x 1.15 x 1.25 = 5.95 c.f.s. DETENTION VOLUME CALCULATION FOR PROPOSED SITE CONDITIONS: Detention is required since more than 60% of the site is impervious. At Q 100 Proposed = CIACf = (0.69 x I x 1.15 x 1.25) = 0.99 x I (in./hr.) Release rate for the entire site is considered to be the maximum allowed for the "Old Town Basin." This is with a maximum of 60% impervious area. Consider that at % impervious = 60, "C" = 0.65 (as average of RH & RMP Zoning from Table 3-2) Therefore, the run-off that may be released undetained from the entire site, including adjacent streets: Q release = 0.65 x 2.10 x 1.15 x 1.00 = 1.57 c.f.s. Page 13 of 18 u DRAINAGE INVESTIGATION CALCULATIONS I i 1 11 t [l Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By. D.R.M. Revised: Nov. 25, 1997 DETENTION VOLUME CALCULATION FOR PROPOSED SITE CONDITIONS: (cont.) Time min. Rainfall Int., I in./hr. Q100 Prop. c.f.s. Vol. @ Q100 cuff[ Q Rel. @ 2 Yr. c.f.s.) Vol. Rel. (cuft) Vol. Diff. (cu.ft. 10 7.10 7.03 4,218 1.57 942 3,276 15 6.00 5.94 5,346 1.57 1,413 3,933 '20 5.15 5.10 6,120 1.57 1,884 4,236 25 4.55 4.50 6,750 1.57 2,355 4,395 30 4.10 4.06 7,308 1.57 2,826 4,482 40 3.45 3.42 8,208 1.57 3,768 4,440 50 2.95 2.92 8,760 1.57 4,710 4,050 60 2.65 2.62 9,432 1.57 5,652 3,780 70 2.35 2.33 9,786 1.57 6,594 3,192 80 2.15 2.13 10 224 1.57 7,536 2 688 90 1 1.95 1 1.93 10,422 1 1.57 1 8,478 1,944 100 1 1.75 1.73 10,380 1 1.57 9 420 960 110 1.60 1.58 10,428 1.57 1 10,362 1 66 120 1.45 1.44 10,368 1.57 1 11,304 1 -936 Therefore, a total of 4,482 cu. ft. of Detention Storage Volume is desired for the site. DETERMINE POND SIZE: Volume to be the combined volume of both South and North Parking Lot Basins. North Basin: High Water Surface Area, At (@ Elev. = 95.6) = 2,490 sq. ft. (Site Basin #2) Pond Bottom Surface Area, Ab (10 x 10) = 100 sq. ft. Max Depth, h = 1.10 ft. Vol. = 1/3 (Ab + At+ 4AbAt) h = 1,133 cu. ft. South Basin: High Water Surface Area, At (@ Elev. = 95.6) = 5,340 sq. ft. (Site Basin #1) Pond Bottom Surface Area, Ab (10 x 10) = 100 sq. ft. Max Depth, h = 1.40 ft. Vol. = 1/3 ( Ab + At + 4AbAt) h = 2,880 cu. ft. The Total Volume available in both basins is: 1,133 + 2,880 = 4,013 cu. ft. 4,013 <_ 4,482 Page 14 of 18 I DRAINAGE INVESTIGATION CALCULATIONS I 1 1 1 0 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By- D.R.M. Revised: Nov. 25, 1997 DETENTION VOLUME CALCULATION FOR PROPOSED SITE CONDITIONS: (cont.) Since the total area being considered includes existing streets and alley, consider only the onsite area. "C" Avg. = ((8,397 x 0.95) + (9,110 x 0.95) + ( 10,993 x 0.15)) / 28,500 = 0.64 At Q100 Proposed = CIACf = (0.64 x I x 0.65 x 1.25) = 0.52 x I (in./hr.) Release rate for the site is considered to be the maximum allowed for the "Old Town Basin." This has been determined by using a maximum C of 0.65. Q release = 0.65 x 2.10 x 0.65 x 1.00 = 0.89 c.f.s. Time min. Rainfall Int., I (in./hr. Q100 Prop. c.f.s.) Vol. @ Q100 (cuft) Q Rel. @ 2 Yr. (c.f.s. Vol. Rel. cuff[. Vol. Diff. cu.ft. 10 7.10 3.69 2 214 0.89 534 1,680 15 6.00 3.12 2,808 0.89 801 2,007 20 5.15 2.68 3 216 0.89 1,068 2,148 25 4.55 2.37 3,555 0.89 1,335 1 2,220 30 4.10 2.13 3,834 0.89 1,602 2,232 40 3.45 1.79 4 296 0.89 2,136 2 160 50 2.95 1.53 4,590 0.89 2,670 1,920 60 2.65 1.38 4,968 0.89 3,204 1,764 70 2.35 1.22 5 124 0.89 3,738 1 386 80 2.15 1.12 5,376 0.89 4,272 1,104 90 1.95 1.01 5,454 0.89 4,806 648 100 1.75 0.91 5 460 0.89 5,340 120 110 1.60 0.83 5,478 0.89 5,874 -396 120 1.45 0.75 5,400 0.89 6,408 -1 008 Therefore, a total of 2,232 cu. ft. of Detention Storage Volume is desired for the site without the adjacent streets and alley considered. Therefore, consider with a request for variance to the design criteria. Provide minimum of 1.0 ft freeboard or additional 33% of total volume for safety factor. 2,232 x 1.33 = 2,969 cu. ft. 4,013 > 2,969 Therefore, OK Page 15 of 18 DRAINAGE INVESTIGATION CALCULATIONS t �_J Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 112 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 DETENTION VOLUME CALCULATION FOR PROPOSED SITE CONDITIONS: (coat.) Consider Combined Basin #1 ,Basin #2 & Offsite. Area= 0.56 a= "C" Avg. _ ((0.30 x 0.18) + (0.54 x 0.20) + (0.75 x 0.18)) / 0.56 = 0.53 At Q100 Proposed = CIACf = (0.53 x I x 0.56 x 1.25) = 0.37 x I (in./hr.) Release rate for the site is considered to be the maximum allowed for the "Old Town Basin." This has been determined by using a maximum C of 0.65. Q release = 0.65 x 2.10 x 0.56 x 1.00 = 0.76 c.f.s. Time min. Rainfall Int., I in./hr. Q100 Prop. c.f.s.) Vol. @ Q100 cu.ft. Q Rel. @ 2 Yr. c.f.s.) Vol. Rel. (cuft) Vol. Diff. (cu.ft. 10 7.10 2.63 1578 0.76 456 1122 15 6.00 2.22 1,998 0.76 684 1,314 20 5.15 1.91 2,292 0.76 912 1 380 25 4.55 1.68 2 520 0.76 1.140 1,380 30 4.10 1.52 2,736 0.76 1,368 1,368 40 3.45 1.28 3 072 0.76 1,824 1 248 50 2.95 1.09 3,270 0.76 2,280 990 60 2.65 0.98 3,528 0.76 2,736 792 70 2.35 0.87 3,654 0.76 3,192 462 80 2.15 - 0.80 3 840 0.76 3,648 192 90 1.95 0.72 3,888 - 0.76 4,104 -216 100 1.75 0.65 3 900 0.76 4 560 -660 110 1.60 0.59 3 894 0.76 5,016 -1 122 120 1.45 0.54 3,888 0.76 5,472 1 584 ' A total of 1,368 cu. ft. of Detention Storage Volume is desired for Basin #1 & Basin #2 plus the Ofssite flow. ' Consider reducing release rate in order to utilize maximum storage capacity available. Available storage volume in combined Basin #1 & Basin #2 = 4,013 cu. ft. Provide 1/3 of available storage volume as safety factor. Therefore, useable storage capacity = 4,013 x 2/3 = 2,675 cu. ft. 1 Page 16 of 18 C DRAINAGE INVESTIGATION CALCULATIONS Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn., Fort Collins By: D.R.M. Revised: Nov. 25, 1997 DETENTION V'OLUb1E CALCULATION FOR PROPOSED SITE CONDITIONS: (cont.) Consider Offsite, Basin # 1 & Basin #2 with reduced release rate. Area = 0.56 acre "C" Avg. = 0.53 At Q 100 Proposed = CIACf = (0.53 x I x 0.56 x 1.25) = 0.37 x I (in./hr.) Q release = 0.25 c.f.s. Time min.(in./hr.) Rainfall Int., I Q100 Prop. c.f.s. Vol. @ Q100 cu.ft Q Rel. @ 2 Yr. c.f.s.) Vol. Rel. (cu.ft.) Vol. Diff. t. 10 7.10 2.63 1,578 0.25 150 �±1,428 15 6.00 2.22 1998 0.25 225 3 20 5.15 1.91 2,292 0.25 300 1 992 25 4.55 1.68 2,520 0.25 375 2,145 30 4.10 1.52 2,736 0.25 450 2,286 40 3.45 1.28 3 072 0.25 600 2,472 50 2.95 1.09 3 270 0.25 750 2,520 60 2.65 0.98 3,528 0.25 900 2,628 70 2.35 0.87 3 654 0.25 1,050 2,604 80 2.15 0.80 3,840 0.25 1,200 2 640' 90 1.95 0.72 3,888 0.25 1 1,350 2,538 100 1.75 0.65 3 900 0.25 1,500 2 400 110 1.60 0.59 3 894 0.25 1,650 2 244 120 1.45 0.54 3,888 0.25 1,800 1 2,088 Therefore, at a release rate of 0.25 c.f.s. a storage volume of 2,628 cu. ft. is desired. Storage volume of 2,675 cu. ft. is available in the combined Basin #1 & Basin #2. DETENTION OUTLET CALCULATION FOR PROPOSED SITE CONDITIONS Determine sizes to provide control at the Inlet located in Basin #2. Determine Orifice Opening Q = 0.39 c.f.s. Orifice Equation: Q = CA 42gh h = Depth - 0.5' = (95.40 - 91.96) - 0.5 = 2.94 ft. Q Release = 0.25 c.f.s. C = 0.65 A = Q / (Cg2gh) = 0.25 / [0.65 4(2 x 32.2 x 2.94)] = 0.03 sq ft. With Round Opening A = rzrA2 Radius, R = 4A/rr = J 0.03/ic = 0.10 ft. Radius, R = ft. x 12 in./ft. = 1.20 in. With Square Opening A = wA2 Width of Opening, W =CIA = 40.03 = 0.17 ft. Width of Opening, W = ft. x 12 in./ft. = 2.04 in. Use 2-1/2" dia. Round Opening or 2" Square Opening for outlet control device. Page 17 of 18 DRAINAGE INVESTIGATION CALCULATIONS 11 11 11 k [1 1 1 Client: ROCKY MOUNTAIN C - M, INC. Project No: GRD-241-97 Project: HOWES / MYRTLE APARTMENTS Date: 3-Mar-97 Location: Lot 7 & N. 1/2 Lot 8, Blk 106, Harrison's Addn.. Fort Collins By. _D.R.M. Revised: Nov. 25, 1997 Determine time required to release total available storage volume, 4,000 cu. ft., at a release rate of 0.39 c.f.s. Time, T = 2,675 / (0.25 x 60) = 178 minutes T = 2 hours 58 minutes Freeboard from Proposed High Water Surface to Finish Floor. Lowest Finish Floor is that for the proposed structures. Elevation = 96.90 Detention High Water Surface Elevation = 95.40 Freeboard = 96.90 - 95.40 = 1.50 feet 1.50 > 1.00 Therefore, OK Lowest Finish Floor is that for the adjacent existing structures. Elevation = 98.35 Detention High Water Surface Elevation = 95.40 CHECK CAPCAITY OF "OVERFLOW": @ Depth of 1-1/2" in 24' wide Driveway Freeboard = 98.35 - 95.40 = 2.95 feet 2.95 >> 1.00 Therefore, OK Area= 1.50 Sq. Ft. Wp = 24.13 Ft. R = a / Wp = 1.5 / 24.13 = 0.06 Ft. n = 0.016 Slope, S = 2% = 0.02 Ft. / Ft. Q = [1.486 A RA2/34S] + n = [1.486 x 1.50 x 0.06A2/3 x 40.021 + 0.016 = 3.03 c.f.s. Total estimated Q100 for Offsite + Basin #1 + Basin #2 = 3.08 c.f.s. 3.03 = 3.08 Therefore, OK Page 18 of 18 I t 11 1 1 0 1 11 1 11 RAINFALL PERFORMANCE STANDARD EVALUATION PROJECT: Myrtle Street Village Apartments STANDARD FORM A COMPLETED BY: Messner Engineering Assoc /Dennis R. Messner DATE: 3-7-97 DEVELOPED ERODIBILITY Asb Lsb Ssb Lb Sb M PS M SUBBA�IN ZONE (ac) (ft) M (feet) Redeveloped Portion of Property Moderate 0.46 180 0.55 . 71.8 MARCH 1991 8-14 DESIGN CRITERIA I 1 1 1 11 EFFECTIVENESS CALCULATIONS PROJECT: Myrtle Street Village Apartments STANDARD FORM B COMPLETED BY: Messner Engineering Assoc./Dennis R. Messner DATE: 3-7-97 Erosion Control C-Factor P-Factor Method Value Value Comment Bare Soil 1.00 1.00 Pavement/Concrete Walk 0.01 1.00 Silt Barrier 1.00 0.50 Sediment Trap 1.00 0.50 Gravel Filter 1.00 0.80 Foundation 0.01 1.00 MAJOR PS SUB AREA BASIN BASIN (Ac) CALCULATIONS Entire Site 71.8 0.46 0.46 Bare Soil = 0:14 Building Foundation.= Q.12 ac. Pavement/Concrete Walk = 0.20 ac. wtd 'C' = [(1.0:x 0.14) + (0.01 x 0.34)) / 0.46 = 0.31 wtd 'P' = 0.5 x'0.5 x 0.5 = 0.13 Eff. = (1 - ('C' x 'P')) x 100 = (1-,(0.31 x 0.13)) x 100 = 96.0 96.0 >> 71.8 Therefore, OK ' MARCH 1991 8-15 DESIGN CRITERIA CONSTRUCTION SEQUENCE PROJECT: Myrt1 a Street v; 11 age Apartments STANDARD FORM C tSEQUENCE. FOR 1998 ONLY COMPLETED BY: Messner Engineering DATE: Dec. 30, 1997 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 I 1998 MONTH I -------- ------------------IJ--- Feb_----- ---- Air- ---- Jun- Jul -Aug -Sep -Oct Nov Dec I I 'OVERLOT GRADING I XXX WIND EROSION CONTROL Soil Roughing I Not Applicable ' Perimeter Barrier Additional Barriers I Site is less that one ( 1 ) acre Vegetative Methods I I ' Soil Sealant I I Other i I ' RAINFALL EROSION CONTROL ' tSod Installation Nettings/Mats/Blankets Other STRUCTURAL: Sediment Trap/Basin ' Inlet Filters Straw Barriers Silt Fence Barriers SandBaos Bare Soil Preparation ' Contour Furrows Terracing Asphalt/Concrete Paving ' Other xxxxx XXXXX '--------------------------------------------------------------------- ' STRUCTURES:. INSTALLED BY VEGETATION/MULCHING CONTRACTOR DATE SUBMITTED HOI/SF-C:1989, MAINTAINED BY APPROVED BY CITY OF FORT COLLINS ON 6" 4, '/j SIDEWI,LK hpDITION 1 Ir2R EDGED SURFACE _ 2 R. •� f. 'OL }/437: I 1/B" • 1-3- MIN. MIN 9" MIN. • 2" MIN. DUMMY JOINT VERTICAL 6e CURB, GUTTER FOR WALKS ADDITION TO EXISTING SIDEWALKS VARIES REFER TO PUN FINISH SLOPE SIDEWKK TO CURB-1/I PER FT. PAVEMENT SURFACE FINISH 1 'D PAVEMENT SURFACE"\ T T, a 2- /5 NEWCONTINUOUS - 'IN CURB AND SIDEWALK DETAIL I F- T I I I inn 5tdnte ST 9 \ I IT Si (ab)') I \ VERTICAL CURB DETAIL DRIVE —OVER CURB & GUTTER CsWE 4 } I \I Existing Existing \���Monhole Sewer i �� c la so Service ++ I I p- I Ezis6n9 I I (- 0 20 60 ,yF 1 Proposed +� I Sanitary ewer I I 3 1" = 20, / Pro ors d 20 4-Plaz I � Manhole Ntl I R R / p Storm IT _ _ _ I Sta. O+OO.bO q 29'� P - _ - 1 �N w r — II XX Manhole 2 F Pavement Cut &I 0• 1 q Inlet qq1 - { o Sla. = 1+02.05 I Patch Area as RtqufrEjdllY -, SIC. = 1+89.18 ANN 'u Rim -. 95.35 I by field c ndCTorp I Inv.12" S-91.61 I T sE�Fole = 94.20 — o iy J1 Inv.12'N= 92.10 g+- IDv.15"N=9136 - ' { E� Existing 2 Proposed 4-IPlex °, Storm Drgin 1d { 1 /4/lyrtic 5tr ilI - T H b.nntal= O'N� ,fin ARE Ver ical= 2 a a m COI m II I Itf pit 11 of 4996 $ 0 rfoce Pr: 1, 4996 1 S. 4994 ";- 4994 Surface Profile ids 4992 4992 - - ERisLIdg 4990 r F; Orifice Finite Location 70 eomme ar ' Propo ed Gas 4988 Sery c '54'3 f 12'• 1 1 • 53't of 12" 4 RCP ® .287. RCP 0 0.307 4986 I c No o S 4984 I I All --._-- - I`- o `— -DID 00 4982 Ed m M mm No aI ------ - s{I it f -- - n II -- -'R_ n -- BIZ H- Y2Z V Z ill a II1Nry cR1L m N oil- o-_ oB i So i. 6" VCP Sewer OR lerify Location OR JptK-griar ib ) Construction-� OF of 15" RCP 0 0.16'e All RCP to be bell & pipe with sealant joints -- 4984 4982' 4990 rMTT RW4E i EXACT 2-MWENT E (SWAT SETRACK To m=ME ,-CbK FME BN R C Mn arml AGRAGERALY it 12 TO AT (20 WIDTH F4awED TON CBUYERCYL AND MOUSTRNL MUM) RIGHT OF MY ARDTH 12' TO 20'. (20' WASH KE D FOR CO KE AND WOUSTMµ MU5) ApIN6: NONE PMR,RC RUST A EXCATTfD M AMATE MAVERTY. ALI ME REOWRED 10 BC USED WITH THE NMRgY RESIDENCE STREET FOR MN A MCC55 TO OFF-STREET eMNING AM WRADESEF L MwTINC ME NMMW LOCAL ESEDENrW FOR ACTOTHER STRIFES, M Yl£Y w ME SEST 0 GRNCE MCg Y LEHiCUUM ACCESS To THE DEAR L( fW MEs S M RT RER. y¢m IMF is uP.. ORNfwa CONNECTIONS TO ALLEYS MUST BE MYp BAneM SC�yI� o � i EyS, in Feel SEINfx 07ON 1 8 TOM KNEES PLACED om A SUBALe `a.M TO ' M MORE. OPOON 2 20 MACWN FDA ENCIA LESS TERM ROM THE EDGE OF THE )ALE" WE E FP�6R WAR S PLACED ASCLOSERT CLOSER AS 3' OM THE RgHr OR WAY CIA ON VRMI[ JAI— IULFv xID� �N{wAr Ff, MBI BETH F 6 k FAMETMMAGREENTEREARY Y I - J 0 ALLEY OPTION B (DRAINAGE TO ONE SIDE) C-Em ECCENTRIC CONE Pusnc usAET Tx°s« L fgQ1RN g2: U0. uSEE wIE 1 . WAN. /FT. 1r AN nc G WAG P GASKET e. T-N-PLACE aM TE MARE MI ErT n x0 WALE" /i a OOFF Per wv BID AS MALAWI K P D W �y W M. US °R FEET Paul s' To 30 m' L :; P•P M B Ba T e' AN YTC11119 BASC STANDARD MANHOLE DETAIL L 49881 B. U 5, I SL(I°b1y 4986 ;.i'o' °M"T'sT PPE o SAW OR END ROLL Mv ELE Tam �3LE Olf e' e PP soa c Mm TO ACTIVE I /II II PIAMED 47OMl P.E sccnax r1eBu smrX °" "'u' n sfcnox rNRu Lac2H GRATED INLET TYPE 13 ITT axs(a GRwAAr ,NTL•L UR SHILL MT EXCEED 3 FEET W CEPS BEDDING REOUIRMENTS XTs AT 6' ASPWEI IO SEK WATCH EXISTING S% AN (rYp) I b m 0 .. °PEIMW 4 r SIO11O11 v 0 RNC j V O rRENi T yU F RACRF LL wTERw ASt TOOTH CLas s MC m t0cON N °8 .r m R(SGFwdYN C o WIDTH J /N% COX '^r W ACDCING MATE. IN. SHALL AIWA MIN E rw a PPE. EONMviGE eRIOR T wrexu SHATION .HALL or N OF m PRIOR To.. ALL EDG(s rnsNxc r sHUL ARKS c o A TACK OT AP W TV ALL SEARSABETWEEN NEW D I.isHNc a vEM(NT sILUU R( s(ALED MTrH u2 c ME T TrAR 'OALL�/ 06 A EXASTMENT SECTION WALL MATCH EXISTING OR 6 ASNMLNC LMLRETF. Hit W MR IS (REA ER 6 REFERENCE STMMRO STREET MPEEIEUTKINS I`-1 •V To ID o TYPICAL TRENCH PATCH IC/I N O V r 0 WE 0 0. L 0. _ m m CR 1-1 m IN MB POWER ro Y IUIY ET F TOMANORMANORLEE1 CS OF mn M ATO N L RI FAST B C P 11MAKF PAEE AGENCY as WCIC s 0 c SLOPE C An ED CR WN o w A FFT 1/4- BELOW 1/4' 70 17) ( DI CONCRETE A0.WSµEENr gNG(5) 6 GROUTED OUT oWECTLY pppp5[ NONE NP$iy��Y YYX • U F �., Ui[RLL wTX MPLE�iOR 9P UTERa WITX OCELFCiOR [Ri z �YYNMLE Z o w PION INMI 16' FORM �y '' G z SECTION MB )i E Fi BARREL sfnox(s) TO MEET TMs REaxicMAT MANHOLE RING AND COVER ADJUSTMENT DETAIL.4 Eli U y aUa J RECTLYwM F TaPPO5C0 IHLIXE UPsiRGY ACTS e ^ Q z UIf RR R(R 9P UIERAL wITH UFFIf CiOR / HEAD MTN „OSIS RESIGNIFICANTLY LOSSES ARE SE., EXCESSIVE rU BUT ME GnFCMT R. OF m 0 LESS THAN WHEN ND DEFLEnW EXISTS E Eat U MANHOLE CHANNELIZING DETAIL Z n. F F OCONCcaw SHOWSa°uA`TEIosIN iIMENT F. K Gi SCsue II+ VE M .. TE PREFw.E2 PLwslc GASKET 00 u O En WµHG .TM roM o HILL TI (� ?' wan YON To ewREL yI a uo AX 1 LF srnol ox F� M0.w° U f PREFw PVSM GSA" Ro -C 1 L CITY of Fort Collins, Colorado w 'o PEO IN UTILITY PUN APPROVAL iI Of nwG n B T.,N+sAa caxaeu RSE APPROVED: T DATE. FEB, 20.t 996 or cr-r,s 4�F a NO a re[ MAINE AIA EE iw R LGI SCALE. /5 NOTED s s aL CHECKED BY ae e. PiD Cg Wf w�� DRAWN. M S R ss M' l aLi m[v 3a p7 ox CHECKED BY 2OFmwR er Its- - - - CHKD- ❑RN ONNOWALL OFF FIRMT ALTE TTp eAsf CHECKED BY: Project ND. 15o.Ti &-Recreot of CARD-241-97 SHALLOW MANHOLE DETAIL CHECKED BY: SHEET CHECKED BY: 4 Of 5 he. City It hart 1 o11T1 Stmmwatnr iarlty erne.nr control ITara r mast he notified at least 24 hours prior to any construction on this site. -�24xI ---�4'13D------- --`L-1--- Au required perimater silt fending shall be install yrior to any land dlstudenn9 Myf UC /U fie:'fi b activity (stocxpfinaq stripping, grading, etc.), arequired control other requionpl measures Shainstalled i the appropriate time in the construction sequence as indkated n NI - r --- -- - In the approved project schedule, oanatrvctlon plans. and erosion control report 1 b n we -disturbance vegetation shall be protected and retained whV"W possible. Rammal I or disturbance or existing vegetation shall be limited to the rea required for T -h-o immediate t t p tons d 1 th hoM1 t practical " a of time. dj Indicates Existing Vertical en. n -..rg n unto, n t i t n I Curb and � Gutter y4} -1 1 � I r a _ \ S'It Fence� `�'1 L SEE DETAIL Existing 4' - - 5. -95'l � Sidewalk 3' = 95 2 9 .4 _ FT 83 at t tad .. afterr - t C i wart of new function. N t a sediments, particularly t served roadway surfaces. shall be removed d Isp d or - rC L -.- --- - - as t t cause their release intoy d- g y 1 II di p =L-()0 Proposed 4-Plex F.F.= 96.90 n t kola Shall exceed ten (to) feet height An stockpiles n n the p � t t d from d t transport by rt roughening. t q d w t r t r q. Any l pis ra q after 30 aav shot a seeded a Iched. �oPCareer MT 1194.741i1 , 96.15 ry OVFRF.om SECTION c 5 LA. in FENN e°p1H ., xAurzr sal` `er be ever ITF v N .. mExee OR a a wipcAsgAvwr ly-wish S[a SILT FENCE DETAIL ttaT fi sGLE 95901 961 1 I ExistingMouse toR ti 1 to Remain r� F.F. 98.35 II yIal N I L_JmIC 4' Walk- 196.00 ell rT Exist to IT I 96.16-F II 1 I jLj M ofI rT-471i4gT1 Exie' I iN-i i i I I g 9811 r- Existing Tap of Curb Slope 4996 =0.80% 4994 ,„ Irwin Ae 4992 4990 .m sx' � raw dui A J ter- I 114988 ,tAXII '.. aavro,l rot¢ ,aw caw wiwEER ter, ,\ hew 2.srEo c„E, air wA, zrMOmR."`°L.zi l �'4986 or RMoEwP'"n, waefe' r:lm°` IN AN waxpr�~'nt No A E A ` anmm sksoo","`u AREA INLET FILTER STRAW BALES NOT TO SCiI£ _ as 95.9001 R_J R« 4« t �CTpyr am_ ,rµ Phil C --o------ - - - - - - - - - sfo-xucE .op ime a.,. COMPfeeso.. uEs-rR t...r.wc � vrz.. 3_tesz c.fs. to Existing Storm Drain 11 ' ar "` -0.25 ="nw O�Iakin UFR Radi Swr.A we herCIT. wl T 1�1_ImI. TLYlatil�.lenl" de 6 y{ 4 roposed 6' Croespon °"^'te ,W Not Applicable O,5 Site Is Less than t Acre 9� 22 a� t:w. roPErir) llllll _ sea - - ��r� �Ew me L ss 94.5 Sidewalks at each side of alley to ber ramped - -die riblu iZordDrrrr = we Iss, Sker _ F95.3 _ all 2 ,Ihe - - Td ADA Start?arM ew"Pn.nikr - - - - - 5. mi .•w• IRAN on 'e O9lorki Coach ��o of Drain ��� R,.Enp l #5Q i Approach - � Revlon =M= Pro aAesYAuR7es�Ed. _. -.__ lax 96.90 ( "Clikii, Existing erw.awe: wn, .• w wteawm w I 95.90 Office Building an swerrre __ rP.Rpm v ui. a mm caLn a 6.2 Sill 5.90 -*93.30 �- enc BIN M R lonollonol 'C 02 gifts I resignation 93.30 .20 Toss wissp.ar�s Drain 1Raaf Drain f offsnE o.30 010 03s l F.F.= 96.90 95.85 96.05 III 020 0.54 051 186 1 '\ r' M2 !�0.75 oa4.__ 1222 . III_ p Proposed Drive -Over 1 ._ '-pia Curb and Gutter 11 /3 034 0.62 0.53 1�1 SEE DETAIL t(II - T 95,9C SEE PROFILE BELOW N M4 0.31 ooso 26 A 4. 5' 5.5 95.70 M5 0.13 l 0.54 0_18 0.64 Use E #1 dicates H. L0 v El 1 ev = I a 'Qi1p1 96.101 40 � 1� House l 5, �lwdin 4'9 Arco 1 at 15. 5.6 95J0 i98.35 I Sale F SEE AIL ta.0+22 1A -96.20 1 96.20 - - -1Y S a.O+DO I Proposed Drainage p ertical 96M\ 1.10 Easement OFFSITE ,r VC rbrb I I -----1 11 SEE DETME ESi tng I 96.35 II G,,,�,„e I l oushe 96.50 wN -- 5F ,.1E7 � F e . I nc 96.30A� .6.20 Y96.54 .30 ------ I - -- ---- Horizontal 1- = 20 relocates Existing Toper Curb Height Warp Gutter to Vertical: 1 2r sphalt �urface from �PL to match Match Slope of 'Existing Qack of Wolk_ brive Approach 4996 Aiditi�al Concrete Drive Approach 17EastProposed FlProper y Line - 1 1' East of Property Line l' I 13t 00' l 19. 0 -05 _U_ 0 lop a,.o.. o I _0 et 1+00 T1Micates .Elristiry _ 4994 Crosspon, egorestruct I[xisting --- 'dsspan -I 4992� __.-_._.. 4990 1 4988 CROSSPAN SECTION TOP rEa I I'll ,r Ae - �D pal RATING we am°"wry SECTION B, B up A umWT ULITT isI ' `PAC rsdrest PA..CAERE no ours SECTION A-e L-- = (73 F-=: Q� ED Typically Indicates Pro lserty Line 5012 Placidly Indicates Existng nd Surface Contour -�ap12_ Typically Indicates Proposed msh 9urtace Contour Indicates Proposed Silt Fence' vNINNINNIN NNNNNNNNNN Drainage Basin Limit Identifier Typically Indicates Existing of 99'11 Surface Spot Elevation TyPliantly Indicates Proposed Pavement Surface Elevation +� or Flow Line of Gutter -.exo Typically Indicates Droirage Flow Direction --Iili- Typically Indicates Storm Drain 9 m E 0 0 0 ot o TO to TO m o V1 a WC U m usof or o'er aeewis'� W POSTIOw w E Rom MR ML Pike AT wn n g � ORIFICE PLATE DETAIL h 5` a U oz Z ono a zoo ,-, w o U 006 z 5 z lid Q W�D E'er 6 WU zt-e�m0 CD0 � 0. z =o so 1 t zo' U c2 Contour Interval = 0.5' all U City of Fort Collins, Colorado w UTILITY PLAN APPROVAL Ir o a APPROVED:-Dol DATE: FEB. 28.1996 CHECKED BY: SCALE: AS NOTED DRAWN: N S R CHECKED BY: SCri D.R.M. wale. tn.ry - - CHECKED BY Project No. arm GRD-241-97 CHECKED BY: SHEET CHECKED BY: 3 of 5