Loading...
HomeMy WebLinkAboutDrainage Reports - 06/08/2005raTIA��,a°• ®rt�l A raved �ieu►i FoRT U, ate FINAL DRAINAGE AND EROSION CONTROL STUDY FOR LOT 1, REPLAT OF TRACT "A" EASTGATE, FIRST FILING PREPARED FOR: FREEMAN ARCHITECTS 2026 BLUE MESA CT LOVELAND, CO 80538 REV. APRIL 2005 DATE: OCTOBER 2004 PROJECT NO. 154 CONSULTING ENGINEER: LOONAN AND ASSOCIATES, INC. 1630 SOUTH COLLEGE AVE. P.O. BOX 270852 FORT COLLINS, CO 80527 1630 S. ( �4ue. ' P. 0. Fax 270952 9azt eoP,4w, e0 80527 (970) 493-2809' ' 9,42 (970) 495- 9735 April 29, 2005 City of Fort Collins ' Stormwater Utility 700 Wood Street Fort Collins, CO 80526 RE: LOT 1, REPLAT OF TRACT "A"EASTGATE, FIRST FILING ' Dear Sirs: Loonan and Associates, Inc. is pleased to submit this Final Drainage Report and Plan for ' the proposed Lot 1, Replat of Tract "A" Eastgate, First Filing site, which is located n the southeast corner of the intersection of Riverside Avenue and Montgomery Street. Please review this Final Drainage Report and Plan at your earliest convenience. We look tforward to your comments and ultimate approval of the Final Drainage Report. ' Please feel free to contact me at (970) 493-2808 if you have additional questions. ' Sincerely, Loonan and Associates, Inc. 1 ' James R. Loonan PROFESSIONAL ENGINEER'S CERTIFICATION I hereby certify that this Final Drainage Plan and Report for Lot 1, Replat of Tract "A" Eastgate, First Filing was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort Collins Storm Drainage Design Criteria for the owners thereof. �a��n n i uuin, Loonan and Assd�\t��i.aS✓S�%�,�� ��HARO'•% I Tames R. Loo ,, Registered Pro?& State of Colorado TABLE OF CONTENTS SECTION I - GENERAL PROJECT LOCATION AND DESCRIPTION Page No. Location I Description of Property 1 SECTION II - DRAINAGE BASINS & SUB -BASINS Major Basin Description 1 Sub -Basin Description 2 SECTION III - DRAINAGE DESIGN CRITERIA Regulations 2 Development Criteria Reference and Constraints 2 Hydrological Criteria 2 Hydraulic Criteria 2 SECTION IV - DRAINAGE FACILITY DESIGN General Concept 3 Specific Details 3 SECTION V — CONCLUSIONS Compliance with Standards 3 Drainage Concept 4 SECTION VI — EROSION AND SEDIMENT CONTROL Discussion 4 General Erosion and Sediment Control Measures 5 Erosion and Sediment Control Plan 5 SECTION VII — REFERENCES 5 APPENDIX EXHIBIT A - Drainage and Erosion Control Plan -VICINITY MAP NOTTO SCALE General Location and Description ' A. Location The Lot 1, Replat of Tract "A" Eastgate, First Filing site is located in Section ' 18, Township 7 North, Range 68 West of the 6th P.M., City of Fort Collins, County of Larimer, State of Colorado. The site is bounded on the north by Riverside Avenue and on the west by Montgomery Street. Tract B is immediately south of the site. B. Description of Property ' The site to be developed consists of approximately 0.41 acres and is generally sloping at approximately 0.7% easterly/northeasterly although several portions ' of the site are fairly flat. The site currently consists of native vegetation and disturbed ground. The site is to be developed into one commercial building with associated parking and driveways. II. Drainage Basins and Sub -Basins ' A. Major Basins Description The site is currently located in the Spring Creek Basin as described in the City ' of Fort Collins Master Stormwater Basin Map. The site is located in the Replat of Tract "A" Eastgate, First Filing. A ' majority of the runoff from the site has been included in the revised detention pond as described in the Final Drainage and Erosion Control Report for Eastgate P.D.P., Replat of Tract B, Replat of Tract A, Eastgate, First Filing by ' Shear Engineering Corporation. According to the runoff coefficient values for Basin D1, listed as 2.09 acres, the 2-year and 100-year runoff coefficients for this basin are 0.70 and 0.88, respectively. The pond is located southeast of ' this site. As of the date of this report, this detention pond had not been re- constructed. However, in the remainder of this report, all southern detention pond references are to this detention pond as described in the Shear ' Engineering report. According to the report by Shear Engineering, the 35-foot drainage easement ' along the western property boundary is for future master drainage infrastructure improvements, which would consist of a trapezoidal swale. The report states that a 2'x10' reinforced concrete box would have the equivalent ' capacity. At the time of these drainage improvements, this box culvert will need to be extended through this site within the easement. The approved drainage plan that the City of Fort Collins has on record for Eastgate P.U.D. (prepared by James H. Stewart & Associates, dated 4/14/1978) shows most of Lot 1 draining to Riverside Avenue. However, ' since the corresponding drainage report and calculations were not available to us, we decided to provide detention ponding for the tributary runoff to Riverside. B. Sub -Basin Description In the developed condition, there will be six subbasins, four of which contribute runoff to the southern detention pond. One subbasin will direct runoff to a proposed detention pond and stormwater quality pond located in the landscape area between the parking lot and Riverside Avenue. In the remainder of this report, all northern detention pond references are to this detention pond. One sub -basin is undetained with runoff directed to Riverside Avenue. Drainage Design Criteria A. Regulations The design criteria for this study are directly from the City of Fort Collins Storm Drainage Design Criteria and Construction Standards Manual. B. Development Criteria Reference and Constraints The developed site will convey runoff to the southern detention pond in Tract B or to the northern detention pond in a safe and effective manner. C. Hydrological Criteria In accordance with the Fort Collins policy, a minor and major storm for the Fort Collins area is identified as the 2-year and 100-year storms, respectively. A major storm for the Fort Collins area has a recurrence interval of 100 years and a total rainfall depth of 3.67 inches for a 2-hour design storm, with a peak intensity of 9.95 in/hr. These storms have been used as a basis for planning and system design. The peak flow rates for design points have been calculated based on the rational method as described in the Storm Drainage Design Criteria with storm duration set equal to the time of concentration for each sub -basin. D. Hydraulic Criteria The majority of the runoff produced by the site will be conveyed to the southern detention pond southeast of the site. The 100-year runoff coefficient times the area (C100*A) will be limited to that reported by Shear Engineering. The remainder of the runoff will be directed to Riverside Avenue and Montgomery Street. The original grading by Stewart & Associates for Lot 1 shows the majority of the runoff directed to Riverside Avenue in a northeasterly direction. We calculated the current 100-year runoff from the site that currently drains to Riverside Avenue and used that value as the 2 IV. V. maximum amount of runoff allowed to drain to Riverside Avenue for the developed conditions. Drainage Facility Design A. General Concept Runoff from Sub -basins A1, A2, B1 and B2 will contribute runoff to the detention pond southeast of the site. These sub -basins consist of rooftop, pavement and landscape. The area of the sub -basins was limited so that C100*A would not exceed that reported by Shear Engineering. The area contributing runoff to the pond from Lot 1 (0.25 acres) was estimated by duplicating the basin boundary from the Shear report to this report. The area was multiplied by 0.88 (C100 reported by Shear) to get 0.22 for C100*A. Sub -basin Cl, located along the northern and northwestern boundaries of this site, also consists of rooftop, pavement and landscape. Runoff is detained in the northern detention pond and is released into Riverside Avenue via a sidewalk culvert. Sub -basin C2, located along the northern boundaries of this site, consists of mostly landscape areas with a small amount of rooftop and sidewalks. The runoff from this sub -basin flows as sheet flow to Riverside Avenue B. Specific Details This site is part of Sub -basin D1 as described in the Eastgate P.D.P by Shear Engineering. The grading plan and the associated drainage basins have been adjusted to assure the combined C*A value does not exceed the assumed value in the Shear Report. The remainder of the site will either be detained in the northern detention pond or will be released undetained to Riverside Avenue. We calculated the current 100-year runoff from the site that currently drains to Riverside Avenue and used that value as the maximum amount of runoff allowed for the developed conditions. The release rate for the northern detention pond was determined by subtracting the 100-year undetained runoff from the current 100-year runoff. Conclusions A. Compliance with Standards All storm drainage calculations followed the guidelines provided by the City of Fort Collins Storm Drainage Design Criteria with the exception of the 3 freeboard of the northern detention pond. We hereby request a variance to allow less than one foot of freeboard on the northern detention pond. B. Drainage Concept The 2-year and 100-year runoff values to the detention pond from Sub -basins Al, A2, B1 and B2 (0.23 acres) are 0.54 cfs and 2.20 cfs, respectively, with the C100*A value remaining the same (0.22) as that estimated from the basin ' boundary defined by Shear Engineering. We are therefore not contributing any additional runoff to the southern detention pond than what was designed for this site. The 2-year and 100-year runoff values not being detained (Sub -basin C2) are 0.08 cfs and 0.36 cfs, respectively. The current Sub -basin EX1 (0.27 acres) ' that is contributing undetained runoff to Riverside Avenue has 2-year and 100-year runoff values of 0.13 cfs and 0.56 cfs, respectively. The 100-year release rate for the northern detention pond was set as 0.20 cfs and resulted in ' requiring 411 cubic feet of storage. The northern detention pond will have 100 cubic feet of water quality volume and 411 cubic feet of detention volume for a total volume of 511 cubic feet. The 100-year water surface will be at an ' elevation of 4942.79 feet. The 100-year depth will be 0.94 feet; however, the maximum depth in the parking lot will be 0.69 feet. ' Water quality will be provided in the southern detention pond designed by Shear Engineering for the runoff for the 0.23 acres of area contributing runoff to the southern pond from this site. We calculated the orifice opening that ' would be required for the storm water quality plate for the northern pond and determine it to be only'/4 " diameter hole. We hereby request a variance to not have the stormwater quality plate on the outlet of the northern pond ' because the size of the hole is so small, it will constantly be plugged. VI. Erosion and Sediment Control ' This section describes methods recommended to control wind erosion, soil erosion and sediment from storm runoff during and after the construction of drainage structures and site grading. This development of erosion control criteria establishes the methods and guidelines used to perform the erosion analysis and develop the erosion control plan. A. Discussion The clearing and stripping of land for site grading, overlot grading or for the construction of drainage structures and swales may cause high -localized erosion rates with subsequent deposition and damage to offsite properties. ' Uncontrolled, such erosion could destroy the aesthetic and practical values of individual sites and cause damage to downstream property. 4 In general, erosion and sediment control measures may consist of minimizing soil exposure, controlling runoff across exposed areas and controlling sediment at drainage structures. Each of these measures is described below and shall be utilized by the developer and/or the contractor during any construction activity occurring at this site. ' B. General Erosion and Sediment Control Measures ' Minimizing Soil Exposure: Where practical, the construction area and duration of soil exposure should be kept to a minimum. All other areas should have a good cover of vegetation or mulch. Grading should be completed as ' soon as possible after it is begun. A temporary cover crop, a permanent vegetative cover crop or other landscaping should be established in disturbed areas. Re -vegetation may consist of native grasses, lawn grasses or various ' winter wheat. Decorative rock, flower gardens or shrubs may also be utilized in the final landscaping to cover the soil. Re -seeded areas should be mulched with straw or hay to protect exposed soil until vegetation is established. Controlled Runoff Across Exposed Areas: Where practical, construction may include constructing temporary swales to intercept and direct storm water around exposed areas. Swales can be constructed to control surface water, which collects on exposed areas and prevents gross erosion in the form of gullies. Riprap, straw bale dikes or other temporary erosion control devices may be installed to control storm water velocities across exposed areas. Sediment Control: Temporary and/or permanent sediment control devices ' may be installed at the major drainage structures and flow concentration points shown on the Drainage Exhibit. Such structures shall be used to intercept and trap sediment once it is produced and prevent it from being ' conveyed offsite onto downstream property. C. Erosion and Sediment Control Plan The following summarizes the overall erosion control plan for this project. The details will be shown on the construction drawings. 1. Silt fence will be utilized downstream of construction activity before it exits the site. Vehicle tracking control will be utilized at the site exit. ' 2. Other erosion control measures will be used as necessary to help minimize erosion for this project. ' VII. References 1 Final Drainage and Erosion Control Report for Eastgate P.D.P. Replat of Tract B, Replat of Tract A, Eastgate, First Filing by Shear Engineering Corporation, February 2004. 1 ' Eastgate PUD Drainage Sheet (3 of 5) by James H. Stewart & Associates ' Consulting Engineers, April 1978 97, ' LOT 1, REPLAT OF TRACT "A" EASTGATE, 1ST FILING Erosion Control Units Unit Cost Est. Qty. Item Cost Silt Fence LF $3.00 365 $1,095.00 Sod SF $0.40 5615 $2,245.95 Vehcile Tracking Control EA $500.00 1 $500.00 TOTAL $3,840.95 BOND @ 150% $V61.43 APPENDIX L O O O IUD O O CD M N N O U o 0 0 0 0 0 0 66 O ¢ C, — tO CO CO I.- O O t0 t'y O O O O O N O U 000 0 6 0 0 0 0 0 0 OO � 0000 00 O O O9 Gcoo N 0 0 0 0 0 O o m 0 0 E U U m f'- coN N � coOI VO1 0� I-- 00 t0 co I,- N N 0 0 0 0 0 0 0 0 0 O U N U N lN N N N N N 000000 O 0 C� rn �c U r l m J� a o 0 o90 0 C N N 6000600 0 0 U UO tOO tOO UO 0 N LOO tOO In 0 0 0 0 0 0 6 O O d m� U U Q O O O O O O O O N O O O O O O O O O 0000000 0 0 a �NlO t17N NN N to U 01 m to 0)0MM m 0 0000000 0a. 0 m �0oo0o°'0 co o 0 0 0 0 0 0 o N 0 0 a to 00m.. U OmmmmoO CD m 0 0 0 0 0 0 0 O O 1 a N O "0 t0 O O O O O O O O O O O O O C C C O 0 0 K t o U a Z 0 0 0 V N N N LD 0 F0- 0 0 0 0 6 0 0 6 0 O ¢ C Z O V N 0 < jo coca QVQW = x w U W W G Y K Q w W V J Q N N N N N N U O r Y U W = = f U Ur U Z O J N Q F O F i r F � O O a W N W J W cV F J J W o W ON J = O c� Z J ng c r W a H oe ga N K 0 W O N Q LL_ ~ = N Z F Z J U S vNro On r, 000000 O cc �Q o Z O z H 0 CD N CD N N O N O N O N W Z O O N NV m Z O O O O O O F O m O G U U O W W O J �cy�� a N m N m U N U Z X W > w W )( G W a O } m Z 0 O �g � U C/) U Y Q W U N N N N N N r U O `1 r U W J O = J N U Q u r O N + (p c - O O a a LL N W J W N H J W a W d ry r O J LL � O c� z J c_ ry a � �r H 00 ga N O W N O Q LL_ ~ = N zr _U Z J U Q 7 N CO 0 1- 1- Q , 0 0 0 � 0 N W O O C I 0 0 0 O w Q r O Z O Z U ~ N N N N N N N Z N m U 2 0 0 0 o c o o O o U O U W U a. WQN mmUU WW y O W O co m c N m 0 w Im 0 U N Z W C7 mO�w zw IN j W ow LL Wo a 0 Q}0O o ZM Z J oO 0 'WIIIC" �i��llllll MEMBER I IMMUNE I 0� �a I�I�III� z ' z J LL F- N ' w Q F- UQ 9 F- LL O g w w 0 Oo 0 O F- N U ' Z 0 65 0Ofw LL o W V5 w� rn 0 W U) w K >a 0 0 LL o z� Z ¢ J 0' ¢ ai 0 O O h SNavw3a N m N + CO Q I IM1<1 (NIW) 11 s (Sdd) u 40ola (ld) y)6ual azls adid u W C adolS (sd0)MOId NEJISK (Sd0)MOId 133N1S W 3dOIS (Sd0) N 0 Lq O N Ci (OV) N s (v �o.o)wns 0 q 0 0 0 (awNU m m o c) � I of ai of 0 (NIW) v> n N (Sd0) o v (oo a(0) O �0 00 00 (2iH/NI) rn rn rn rn rn m I of ai m Ci of CS (Uln) �) U) U) N N O to) v� m� rnv VJO. �o 00 00 00 00 00 10. dd300 0 Ci o o rn =1=10WU 'a 00 (Otl) tl321 a o 0 0 o 00 O O 0 0 fA Z O NOIS30 V3N Q m m U U z O U 1NIOd � M Q NOIS30 a o IN 0 ININI o n c O OJ z 0 w i W K G V) z O F 0 z O U a LOT 1, REPLAT OF TRACT "A" EASTGATE, 1ST FILING 100 Year Storm DETENTION POND TRIBUTARY AREA (acres) = 0.10 AVG C = 0.94 C x A = 0.09 UPSTREAM POND (Qin), cfs = 0.00 DESIGN Qout, cfs = 0.20 = .056 (Q Hist) -0.36 (Q 100 for C2) Qtrib-in TOTAL VOLUME in VOLUME out VOLUME OF TIME i (CCFiA) Qpond-in Qin (Qin x T'x 60) (Qout x T x 60) PONDING MIN. in/hr cfs cfs cfs CU FT CU FT CU FT 5 9.95 0.94 0 0.94 282 60 222 10 7.72 0.73 0 0.73 437 119 318 15 6.52 0.62 0 0.62 554 179 375 20 5.60 0.53 0 0.53 634 238 396 25 4.98 0.47 0 0.47 705 298 407 30 4.52 0.43 0 0.43 768 357 411 35 4.08 0.39 0 0.39 809 417 392 40 3.74 0.35 0 0.35 847 476 371 45 3.46 0.33 0 0.33 882 536 346 50 3.23 0.30 0 0.30 914 595 319 55 3.03 0.29 0 0.29 944 655 289 60 2.86 0.27 0 0.27 972 714 257 70 2.65 0.25 0 0.25 1050 833 217 80 2.40 0.23 0 0.23 1087 952 135 90 2.25 0.21 0 0.21 1147 1071 75 100 2.10 0.20 0 0.20 1189 1190 0 110 2.00 0.19 0 0.19 1246 1309 0 120 1.95 0.18 0 0.18 1325 1428 0 LOT 1, REPLAT OF TRACT "A" EASTGATE, 1ST FILING Detention Pond Volumes Delta Volume=(D/3)(A1+A2+SQRT(AIA2)) DELTA ELEV AREA VOLUM VOLUM E E FT FT FT3 FT3 41.85 0 0 0 42 11 1 1 42.5 599 115 116 43 2300 679 795 WQ VOLUME I TOTAL Volume = 100 411 511 FT3 W.S. Elevation = Elev43 - Elev42.5 (V01Req"1 ed-Vo142.5)+Elev42.5 V0143 - VOL2.5 = 42.79 FT 100-year Depth (D) = 0.94 FT Top of Berm = 42.88 FT Freeboard = 0.09 FT Orifice Onenin Q= CA(2gH)1/2 A= Q C(2gH)v2 C = 0.65 Qout = 0.20 cfs g = 32.2 fps diam = 0.23 FT H = D-1/2diam 0.83 FT A = 0.04 FT2 A = 6.03 IN2 diam = 2.77 IN Emergency Spillway Q = CLH" C = 2.67 H = 0.17 FT Q100 = 0.94 cfs L = 5.02 FT V=Q/(L*l 0.37 FPS Use 2 3/4" DIA OPENING Use 6 FT LOT 1, REPLAT OF TRACT "A" EASTGATE, 1 ST FILING WATER QUALITY Total acreage to detention pond = 0.10 acres I = (Area of Pave + Roof)/(Total Area) = 0.70 Time = 40 hours, from Figure EDB-2 or SQ-2, WQCV = 0.28 watershed inches Required Storage = (WQCV/12)*Area = 100 cubic feet or 0.00 acre-ft ELEV DELTA VOLUM AREA VOLUM E E FT FT' FT' 1771-3 41.85 0 0 0 42 11 1 1 42.5 599 115 116 43 2300 679 795 Elev = Elev43 - Elev42 (VOlRCQuired-V0142)+Elev42 V0143 - Vo142 = 42.43 FT HwQcv = 0.58 FT From Figure EDB-3, Area per row a=(WQCV/K40) K40 = 0.0322 where K=0.013DwQ2+0.22DwQ-0.10 a = 0.0712 in Figure 5 Use 1 columnn'- 1/4" hole Curb Cut Q = CLH3/2 C = 2.67 H = height of curb = 0.5 ft L (length of curb opening) Q (capacity of curb cut) (ft) (cfs) 1 0.94 1.5 1.42 2 1.89 3 2.83 4 3.78 5 4.72 6 5.66 7 6.61 8 7.55 9 8.50 10 9.44 11 10.38 12 11.33 13 12.27 14 13.22 15 14.16 16 15.10 17 16.05 18 16.99 H 6t�(,u o� 3-2 d. 10 c- S Q OC) �I- 1, 4 1�c S Q oc>asr GI- p.Nc -5 (I C) a �C�rb cam+ w� c,U U W 3 x b Cd xp N' N vi O N v1 Nto C N C a N O O vl M U cl U II II II II II II II 0 • ,2ININIMIMIqIt"nI �llololololololol ¢I�IoIoI�I�I�I�INI a-41 ININIcIMI":t�I °INIM1--ni IwI O O M 1, to O\ O ^ to O M to t� 00 O O rn O V1 0 rn O d �^ tn [- O N v1 [- O a w o 0 0 0 0 0 0 U ^ o v, o v, o to o cv cq en ri d H Q M M M enM O C O C T�2 0 0 0 0 C 6 EFFECTIVENESS CALCULATIONS PROJECT : /-0 F 1 R e 1-Y o Ty c. ,: } /s CUS f� cue 1 F //nS STANDARD FORM B COMPLETED BY: ty-). J { i DATE: Erosion Control C-Factor P-Factor Method Value Value Comment Wd/A5p ,r,14-lconcve% 0,01 / 00 S 1 14- F n ce- / . CL) 0.5-0 Soda-vo5S MAJOR PS SUB AREA BASIN BASIN (Ac) CALCULATIONS 0,7 GPa 55e�4 c.o `l �i 0( C = Q •� 6t-,4-cf P = 2 51 Y S�Gee = 1.41 90 TG tole 8- a PS G,::....y pnvvr,0 - o 13 93 iofcc O. Cvid c qy c'6) >76 MARCH 1991 8-15 DESIGN CRITERIA ' LOT 1, REPLAT OF TRACT "A" EASTGATE, 1ST FILING Erosion Control Units Unit Cost Est. Qty. Item Cost Silt Fence LF $3.00 365 $1,095.00 Sod SF $0.40 5615 $2,245.95 Vehcile Tracking Control EA $500.00 1 $500.00 TOTAL $3,840.95 BOND @ 150% $5,761.43 No Text City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (5 minutes - 30 minutes) Figure 3-1a Duration (minutes) 2-year Intensity in/hr 10-year Intensity in/hr 100-year Intensity 5.00 2.85 4.87 6.00 2.67 4.56 7.00 2.52 f!2.30 4.31 t03 8.00 2.40 4.10 9.00 3.93 10.00 2.21 1 3.78 7.72 11.00 2.13 1 3.63$V7.4212.00 2.05 3.5013.00 1.98 3.3914.00 1.92 3.2915.00 1.87 3.1916.00 1.81 3.0817.00 1.75 2.99 18.00 1.70 2.90 5.92 19.00 1.65 2.82 5.75 20.00 1.61 2.74 5.60 21.00 1.56 2.67 5.46 22.00 1.53 2.61 5.32 23.00 1.49 2.55 5.20 24.00 1.46 2.49 5.09 25.00 1.43 2.44 4.98 26.00 1.40 2.39 4.87 27.00 1.37 .2.34 4.78 28:00 1.34 2.29 4.69 29.00 1.32 2.25 4.60 30.00 1 1.30 1 2.21 1 4.52 City of Fort Collins Rainfall Intensity -Duration -Frequency Table for using the Rational Method (31 minutes - 60 minutes) Figure 3-1b Duration 2-year (minutes) Intensity in/hr 10-year Intensity in/hr 100-year Intensity in/hr 31.00 1.27 2.16 4.42 32.00 1.24 2.12 4.33 33.00 1.22 2.08 4.24 34.00 1.19 2.04 4.16 35.00 1.17 2.00 4.08 36.00 1.15 1.96 4.01 37.00 1.13 1.93 3.93 38.00 1.11 1.89 3.87 39.00 1.09 1.86 3.80 40.00 1.07 1.83 3.74 41.00 1.05 .1.80 3.68 42.00 1.04 1.77 3.62 43.00 1.02 1.74 3.56 44.00 1.01 1.72 3.51 45.00 0.99 1.69 3.46 46.00 0.98 1.67 3.41 47.00 0.96 1.64 3.36 48.00 0.95 1.62 3.31 49.00 0.94 1..60 3.27 50.00 0.92 1.58 3.23 51.00 0.91 1.56 3.18 52.00 0.90 1.54 3.14 53.00 0.89 1.52 3.10 54.00 0.88 1.50 3.07 55.00 0.87 1.48 3.03 56.00 0.86 1.47 2.99 57.00 0.85 1.45 2.96 58.00 0.84 1.43 2.92 59.00 0.83 1.42 2.89 60.00 0.82 1.40 2.86 City of Fort Collins Design Storms for using SWMM Figure 3-1c Time (min) 2-year Intensity in/hr 5-year Intensity in/hr Intensitynsity in/hr/hr 10-yearWO.81.05 year 100-year Intensity in/hr0.29 0.40 0.4979 1.00 0.33 0.45 0.5690 1.14 0.38 0.53 0.65 1.33 /-v u.o4 u.tsy , 1.09 1.41 1.77 2.23 25 0.81 1.13 1.39 1.80 2.25 2.84 30 1.57 2.19 2.69 3.48 4.36 5.49 35 2.85 3.97 4.87 6.30 7.90 9.95 40 1.18 1.64 2.02 2.61 3.27 4.12 . 45 0.71 0.99 1.21 1.57 1.97 2.48 50 0.42 0.58 0.71 0.92 1.16 1.46 55 0.35 0.49 0.60 0.77 0.97 60 0.30 0.42 0.52 0.67 0.84 .1.22. 1.06 65 0.20 0.28 0.39 0.62 0.79 1.00 70 0.19 0.27 0.37 0.59 0.75 0.95 75 0.18 0.25 0.35 0.56 0.72 0.91 80 0.17 0. - - 0.34 0.54 0.69 0.87 85 0.17 0.23 0.32 0.52 0.66 0.84 90 0.16 0.22 0.31 0.50 0.64 0.81 95 0.15 0.21 0.30 0.48 0.62 0.78 100 0.15 0.20 0.29 0.47 0.60 0.75 105 0.14 0.19 0.28 0.45 0.58 0.73 110 0.14 0.19 0.27 0.44 0.56 0.71 115 0,13 0.18 0.26 0.42 0.54 0.69 120 0.13 0.18 0.25 0.41 0.53 0.67 SECTION 3. HYDROLOGY STANDARDS 3.1 General Design Storms All drainage systems have to take into consideration two separate and distinct drainage problems. The first is the initial storm which occurs at fairly regular intervals, usually based on the two to ten-year storm, depending on land use. The second is the major storm which is usually based on an infrequent storm, such as the 100-year storm. In some instances the major storm routing will not be the same as the initial storm. In this case, a complete set of drainage plans shall be submitted for each storm system. 3.1.1 Initial Storm Provisions ' As stated before, the initial storm shall be based on the two to ten-year storm. The objectives of such drainage system planning are to minimize inconvenience, to protect against recurring minor damage and to reduce maintenance costs in order to create an orderly drainage system at a reasonable cost for the urban resident. The initial storm drainage system may include such facilities as curb and gutter, storm sewer and open drainageways, and detention facilities. 3.1.2 Major Storm Provisions ' The major storm shall be considered the 100-year storm. The objectives of the major storm planning are to eliminate substantial property damage or loss of life. Major drainage systems may include storm sewers, open drainageways, and ' detention facilities. The correlation between the initial and major storm system shall be analyzed to insure a well coordinated drainage system. 3.1.3 Storm Frequency The initial and major storm design frequencies shall not be less than those found in the following table: ' Table 3-1 DESIGN STORM FREQUENCIES ' Land Use or Zonings Design Storm Return Period Initial Storm Major Storm Residential: ' (RE,RL,RLP,RP, ML,RM,RMP, RIM, MM,RR) .............................. 2-year 100-year Business: (BG,BL,BP,HB,C,IL,IP,IG)................. 10-year 100-year ' Public Building Areas ...................... 10 -year 100-year Parks, Greenbelts, etc ...................... 2-year 100-year Open Channels 6 Drainageways 100-year Detention Facilities -- 100-year ' HSee Table 3-2 for zoning definitions 3.1.4 Rainfall Intensities The rainfall intensities to be used in the computation of runoff shall be obtained from the Rainfall Intensity Duration Curves for the City of Fort Collins, included in these specifications as Figure 3.1. 3.1.5 Runoff Computations Storm Runoff computations for both the initial and major storm 'shall comply with the criteria set forth in Section 3.2 "Analysis Methodology.-' All runoff calculations made in the design of both initial and major drainage systems shall be included with the storm drainage plans in the form of a Drainage Report. Reports submitted for approval should have a typed narrative with computations and maps in a legible form. May 1984 Revised January 1997 Design Criteria 3-1 DRAINAGE CRITERIA MANUAL 31 2( z w U w a 1C Z w a O 5 w e 3 O U 2 ¢ w I- Q �j 1 RUNOFF .2 .3 .5 ' 1 1,'5 2 3 5 10 20 VELOCITY IN FEET PER SECOND Figure 3-3 ESTIMATE OF AVERAGE FLOW VELOCITY FOR USE WITH THE RATIONAL FORMULA. MOST FREQUENTLY OCCURRING -UNDEVELOPED' LAND SURFACES IN THE DENVER REGION. REFERENCE:: "Urban Hydrology For Small Watersheds' Technical Release No. 55, USDA. SCS Jan. 1975. 5-1-84 URBAN DRAINAGE & FLOOD CONTROL DISTRICT ' 3.1.6 Runoff Coefficients ' The runoff coefficients to be used with the Rational Method referred to in Section 3.2 "Analysis Methodology" can be determined based on zoning classifications if the character of the surface is unknown. However, the final drainage study must calculate a composite coefficient using Table 3-3. Table 3-2 ' lists the runoff coefficients for the various types of zoning along with the zoning definitions. Table 3-3 lists coefficients for the different kinds of surfaces. Since the Land Development Guidance System for Fort Collins allows land development to occur which may vary the zoningre a nd runoff coefficients different from those specified in Table 3 2, the produce ' coefficients should not be based solely on the zoning classifications. The runoff coefficient used for design should be based on the actual conditions of the proposed development. The Composite Runoff Coefficient shall be calculated using the following formula: n C = (CiAi) / At i=1 Where C = Composite Runoff Coefficient Ci= Runoff Coefficient for specific area Al A1= Areas of surface with runoff coefficient of C1 n = Number of different surfaces to be considered At= Total area over which C is applicable; the sum of all Al's is equal to A, Table 3-2 RATIONAL METHOD MINOR STORM RUNOFF COEFFICIENTS FOR ZONING CLASSIFICATIONS Description of Area or Zonina Coeff Business. BP,BL.................................... 0.85 Business: BG,HB,C ............................... 0.95 Industrial: IL,IP .............................. •... 0.85 Industrial: IG.. 0.5 Residential: RE,RLP.. .............................. 0.45 Residential: RL,ML,RP ............................... 0.50 Residential: RLM,RMP................................ 0.60 Residential: RM,MM..................... 0.65 RH..................................... 0.70 Residential: Parks, Cemeteries 0.25 Playgrounds 0.35 Railroad Yard Areas ........................... 0.40 35 Unimproved Areas .................................... 0.20 Zoning Definitions R-E Estate Residential District - a low density residential area primarily in outlying areas with a minimum lot area of 9,000 square feet. R-L Low Density Residential District - low density residential areas located throughout the City with a minimum lot area of 6,000 square feet. R-M Medium Density Residential District - both low and medium density residential areas with a minimum lot area of 6,000 square feet for one - family or two-family dwellings and 9,000 square feet for a multiple family dwelling. R-H High Density Residential District - high density residential areas with a minimum lot area of 6,000 square feet for one -family or two-family dwellings, 9,000 square feet for a multiple family dwelling, and 12,000 square feet for other specified uses. R-P Planned Residential District - (PUD) to provide a variation minimum lot area of 6,000 square May 1984 Revised January 1997 designation of areas planned as a unit in use and building placements with a feet. Design Criteria 3-3 R-L-P Low Density Planned Residential District - areas planned as a unit (PUD) ' to permit variations in use, density and building placements, with a minimum lot area of 6,000 square feet. R-M-P Medium Density Planned Residential District - designation for medium ' density areas planned as a unit (PUD) to provide a variation in use and building placements with a minimum lot area of 6,000 square feet. R-L-M Low Density Multiple Family District - areas containing low density multiple family units or any other use in the R-L District with a minimum lot area of 6,000 square feet for one -family or two-family dwellings and 9,000 square feet for multiple -family dwellings. ' M-L Low Density Mobile Home District - designation for areas of mobile home parks containing independent mobile homes not exceeding 6 units per acre. M-M Medium Density Mobile Home District - designation for areas of mobile ' home parks containing independent mobile homes not exceeding 12 units per acre. B-G General Business District - district designation for downtown business areas, including a variety of permitted uses, with minimum lot areas equal to 1/2 of the total floor area of the building. B-P Planned Business District - designates areas planned as unit developments ' to provide business services while protecting the surrounding residential areas with minimum lot areas the same as R-M. H-B Highway Business District - designates an area of automobile -orientated ' businesses with a minimum lot area equal to 112 of the total floor area of the building. B-L Limited Business District - designates areas for neighborhood convenience ' centers, including a variety of community uses with minimum lot areas equal to two times the total floor area of the building. C Commercial District - designates areas of commercial, service and storage areas. I-L Limited Industrial District - designates areas of light industrial uses with a minimum area of lot equal to two times the total floor area of the ' building not to be less than 20,000 square feet. I-P Industrial Park District - designates light industrial park areas containing controlled industrial uses with minimum lot areas equal to two times the total floor area of the building not to be less than 20,000 square feet. I-G General Industrial District - designates areas of major industrial development. T Transition District - designates areas which are in a transitional stage with regard to ultimate development. For current and more explicit definitions of land uses and zoning classifications, refer to the Code of the City of Fort Collins, Chapters 99 and 118. ' May Design Criteria Revisedsed January 1997 ' 3-4 Table 3-3 ' RATIONAL METHOD RUNOFF COEFFICIENTS FOR COMPOSITE ANALYSIS Character of Surface Runoff Coefficient Streets, Parking Lots, Drives: . Asphalt ...................................... 0.95 Concrete ..................................... 0.95 Gravel....................................... 0.50 Roofs.......................................... 0.95 Lawns, Sandy Soil: ' Flat<28................................... 0.10.1 Average 2 to 7$...5 5 Steep>7%.................................... 0.20 ' Lawns, Heavy Soil: Flat<2%..................................... 0.20 Average 2 to 7%........................... 0.25 Steep>7%..................................... 0.35 ' 3.1.7 Time of Concentration In order to use the Rainfall Intensity Duration Curve, the time of ' concentration must be known. The time of concentration, T„ represents the time for water to flow from the most remote part of the drainage basin under consideration to the design point under consideration. The time of concentration can be represented by the following equation. T, = t,v + tt Where: ' T, = Time of Concentration, minutes t„ = overland flow time, minutes tt= travel time in the gutter, swale, or storm sewer, minutes ' The overland flow time, t,,, ,can be determined either by the following equation or the "Overland Time of Flow Curves" from the Urban Storm Drainage Criteria Manual, included in this report (See Figure 3-2) ' L87(LI-�f)Dl/2 Tw S113 ' Where: T,,= Overland Flow Time of Concentration, minutes S = Slope, % C = Rational Method Runoff Coefficient D = Length of Overland Flow, feet (500, maximum) Ct = Frequency Adjustment Factor The travel time, tt, in the gutter, swale, or storm sewer can be estimated with the help of Figure 3-3. 3.1.9 Adjustment for Infrequent Storms ' The preceding variables are based on the initial storm, that is, the two to ten year storms. For storms with higher intensities an adjustment of the runoff coefficient is required because of the lessening amount of infiltration, depression retention, and other losses that have a proportionally smaller effect on storm runoff. These frequency adjustment factors are found in Table 3-4. ' May Design Criteria Revisedsed January 1997 ' 3-5 Table 3-4 RATIONAL METHOD FREQUENCY ADJUSTMENT FACTORS Storm Return Period Frequency Factor (years) C. 2 to 10 1.00 11 to 25 1.10 26 to 50 1.20 51 to 100 1.25 Note: The product of C times Cf shall not exceed 1.00 3.2 Analysis Methodology The methods presented in this section for use in the determination of runoff at specific design points in the drainage system are currently under review by the Stormwater Utility. Until detailed criteria for hydrologic modeling are developed, the accepted methods for hydrologic analysis are (1) the Rational Method and (2) UDSWM2- PC. The Stormwater Utility shall determine circumstances requiring computer modeling with UDSWM2-PC. Early contact with the Stormwater Utility is encouraged for the determination of the appropriate method. Where applicable, drainage systems proposed for construction should provide the minimum protection as determined by the methodology so mentioned above. 3.2.1 Rational Method The Rational Method is recommended only for sites less than 5 acres. The runoff may be calculated by the Rational Method, which is essentially the following equation: Q = ClCIA Where Q = Flow Quantity, cfs A = Total Area of Basin, acres Cf= Storm Frequency Adjustment Factor (See Section 3.1.8) C = Runoff Coefficient (See Section 3.1.6) I = Rainfall Intensity, inches per hour (See Section 3.1.4) 3.2.2 UDSWM2-Pc For circumstances requiring computer modeling, the design storm hydrographs shall be determined using UDSWM2-PC. Basin and conveyance element parameters shall be developed from the physical characteristics of the development. Refer to the UDSWM2-PC User's Manual' for modeling methodology and development. 'Urban Drainage and Flood Control District, March 1985 3.2.2.1 Surface Storage and Infiltration Table 3-5 gives those values for surface storage for pervious and impervious surfaces. Table 3-6 gives the infiltration rates to be used with UDSWM2-PC. Table 3-5 VALUES FOR SURFACE STORAGE (All Values in Inches) (For Use with UDSWM2-PC) Impervious Areas .................. .100 Pervious Areas .................... .300 May 1984 Revised January 1997 Design Criteria 3-6 o rn0%0oo o 44tntnln In WmmmW 0 mo mmooO000 o 4444tntnlnlnlntn qzr WWmmmWmmWm 0 mmmommmoommm000 . . . . . . . . . . . ... . . o ��vv�����a��rintntn M W W m m m W W W m W W m W W m o nmmmrno,o+mrnrno�o+o+a�o+o+a,o�rnrn . . . . . . . . . . . . . . . . . o vv�rcv�a�r�rv�rv�rvav�v�� N m m W W m m W W W W W m m m W m W m W W 0 oMvtn�c�o�olornnrrnnrnnnnmmWWWm . . . . . . . . . . . . . . . . . . . . . . . . O o vaeraerc��srvav�rsrvv����cr��a�� ri m W O0 00 m W W W W W W m W W W m m W m W W W W m W m p o cOc�Ir+�rintnln�alDto�o�olDrrrnnnnrnrWWW a a+ Ma�v���rsra��r����rasrvv�r���v�a U mmmmmmwmmmmmoommmmmmcommmoomm o �DONMvvtntnlntn�D�n�D/vm�o�oto�D�onnrrnr . . . . . . . . . . . . . . . . . . . . z W W W W W W W m W W m W W W W W W ODOD W W W W W W W aO er 01 ri N M M d' d' d' -W In In In to to to In In W W W 10 %a l0 W r U aDcoaoc0c0cDD0coaoWWWmWmmmWWWmWWmWW a O 0ww0T-Ir"INNMMMMd'V'srsrd'd'd'er W If'1111111t0�0 . . . . . . . . . • . . . . . . . . . . . . . . . O 1D M M M aT V er V d er d d er er er d V V er sM er sr er V er er 44 mW W WmmWCO CO ODmWWWmW WmmW WmmWmm 49 . o In Nlnnm0100 r1 r1 •-INNNNNMMM!"1M t! erd d d 1 O AP • . . . . . . . CD OD CD OD GO OD m OD OD W W W W W W W W W W W W W W W W W W to W ac 04InM.m000000 �i 34 NNMMt'1MMMMMMMMMMMMM M M M d'-Wo v'mry EHa to MWWWWmWWWW W WWWW Wm mW WmCID WmCID W o telnWor-I N(nV-etntnIn%0%D%0%0%0ntnrrWWW0%M [-4 . . . . . . . . . . . • co tr r4 N N M M M M M M M M M M M M M M M M M M M M M M M OD OD CD OD W W W W W W W W W W W W W W W W W W W W W W W W rl.-Ilnn WOOrINNMMMsrd WVd 00In0 00rl n M riNNNNP"IM MC•1 rr1MMMMMMMMMMMMMMMM m000DWmODODWWO000W0000WW WWmW W W W W Wm WO MNtpW 010 •-INNMMM V'd'tr d' V'd'In In In In \p 1p tp \p L>» M O.-iriri.-INNNNNNNNNNNNNNNNNNNNN wODmmmWODWODmWWmmmmWWmW WmWWmmW a to to In a+NM'rInVDrnnWWW0ON(IN (AM000000 a N alOO 4•-1r4.-1e4r-1r1rI•-1r4rirI•-Irar;.-{riNNNNNN w nWmmWWCID WWWWWWWWWCID WWWWWCID Wmm z O -0 In O MInW W CO 0% 000 r-I ri r4 r-I N N N N C9(n M M (nM N co mOOOOOOO.-1r-I ri r-11-I 41; 1; r41; ri 4 ri 11 ri 41; nn0000ODCID OD00000DWmmmWWWmmWmWWmmm In co Nm ri it lnr nmmM00 r1 r4 r-I -I r4 NNNMMMMM 1; t0 W W 0:0;010; 0;0;0;0;000000000000000 rnrnnnnnnrrm000DODCID WmmW Wm Wm Wm O t0MOd'n0%0r-I NMMerd'InInInInW 010l0rr,%0W 0 r+ dlonnnncOcDDDcDWaDODCDmmmCID mWWWWWWW rrnnnrrnnnrnrrnrnrnnnrnnrr In 0)0VWr-ODW nrr%0%0WLn W rMMNNM%0-W -I0%%D O ONNNNNNNNNNNNNNNNNC4C44 41;1;00 rnnrnnnnnnnnrrnnnnrnnrnnnr x 3E4., 000000OO000000000000000000 O O P 00000000000000000000000000 0z14 HNMc 0 w N W 009-1NMd 0wt� m m 0 0 0 0 0 m 0 4414— rlrirlrlrlrleir-IrIrINNMMt! d to a MARCH 1991 8-4. DESIGN CRITERIA ' A.b = Sub -basin area (acres) 2. Evaluate final grade contours and calculate an average weighted slope using the following equation. ' Sb = (S., x Aie►/Ab Eqn. 8-4 Where Sb = Average slope (%) ' L6b = Sub -basin slope (%) A�b = Sub -basin area (acres) ' 3. Find Performance Standard by using Table A. 4. Determine the erodibility zone(s) from the maps at the end of this document. ' 8.1.2.4 Effectiveness The City of Fort Collins requires that all submittals demonstrate that methods proposed for erosion control shall be effective in reducing sediment. For ' rainfall erosion, effectiveness shall be calculated using the following equation and Standard Forth B (SF-B). EFF = [1- C x P) x 100 Eqn. 8-5 ' Where EFF = Effectiveness (%) C = C-Factor P = P-Factor ' Cover factor (C-Factor) values represent the ratio of soil loss from land under treated conditions (e.g., vegetation, mulch) to corresponding losses from bare ' ground conditions. C-Factor values are associated with vegetation, mulches, sealants and pavement as illustrated in Table 8-B and Figure 8-A. Practice factor (P-Factor) values represent the ratio of soil loss with a general ' surface condition (e.g., straw bales, sediment basins) to soil loss from disturbed bare ground conditions. P-Factor values are associated with structural erosion control methods as illustrated in Table 8-B. ' The following equation shall be used to calculate net effectiveness for each major drainage basin. EFFMI = (EFF X A,bVA.b Eqn. 8-6 THE NET EFFECTIVENESS OF SUBBASINS SHALL BE EQUAL TO OR GREATER THAN THE PERFORMANCE STANDARD. 8.1.3 Installation Sequence Once an erosion control plan has been developed, an installation sequence shall be completed using Standard Form C (SF-C). The erosion control installation schedule shall be coordinated with the construction schedule. 8.1.4 Elements of an Erosion Control Plan An erosion control plan shall address how movement of sediment due to both wind and rainfall will be mitigated. Fortunately, controlling rainfall erosion often results in Control- ling wind erosion. Consequently, an erosion control plan for rainfall erosion is usually completed first. MARCH 1991 8-5 DESIGN CRITERIA ' Table 8B C-Factors and P-Factors for Evaluating EFF Values. Treatment C-Factor P-Factor ' BARE SOIL Packedand smooth................................................................ 1.00 1.00 Freshlydisked........................................................................ 1.00 0.90 ' Rough irregular surface........................................................... 1.00 0.90 SEDIMENT BASIN/TRAP................................................................. 1.00 0.50111 ' STRAW BALE BARRIER, GRAVEL FILTER, SAND BAG ........................ 1.00 0.80 SILT FENCE BARRIER..................................................................... 1.00 0.50 ' ASPHALT/CONCRETE PAVEMENT ................................................... 0.01 1.00 ESTABLISHED DRY LAND (NATIVE) GRASS .......................... See Fig. 8-A 1.00 ' SOD GRASS................................................................................. 0.01 1.00 TEMPORARY VEGETATION/COVER CROPS .................................... 0.45121 1.00 ' HYDRAULIC MULCH @ 2 TONS/ACRE........................................... 0.1 om 1.00 SOILSEALANT....................................................................0.01-0.601•' 1.00 ' EROSION CONTROL MATS/BLANKETS............................................ 0.10 1.00 GRAVEL MULCH Mulch shall consist of gravel having a diameter of approximately 1 /4" to 1 1 /2" and applied at a rate of at least 135 tons/acre.............. 0.05 1.00 HAY OR STRAW DRY MULCH ' After olantina crass seed apply mulch at a rate of 2 tons/acre (minimum) and adequately anchor, tack or crimp material into the soil. Sloe % 1 to 05 .............................................................................. 0.06 6 to 10 1.00 ..................:.......................................................... 0.06 11 to 15 1.00 .............................................................................0.07 16 to 20 1.00 ............................................................................. 0.11 21 to 25 1.00 ............................................................................. 0.14 1 25 to 33 1.00 .............................................................................0.17 >33 1.00 .......................................................................... 0.20 1.00 ' NOTE: Use of other C-Factor or P-Factor values reported in this table must be substantiated by documentation. (1) Must be constructed as the first step in overlot grading. (2) Assumes planting by dates identified in Table 11-4, thus dry or hydraulic mulches are not required. (3) Hydraulic mulches shall be used only between March 15 and May 15 unless irrigated. t (4) Value used must be substantiated by documentation. ' MARCH 1991 8-6 DESIGN CRITERIA REFERENCES Y t' 3,PC.R t'. 4 Final Drainage and Erosion Control Report For EastLyate P.D.P. Replat of Tract B, Replat of Tract A, Eastgate, First Filing Fort Collins, Colorado Prepared for: Premier Custom Builders,- 1420 G Blue Spruce Driv Fort Collins, Colorado 805. Prepared by: Shear Engineering Corporation Project No: 1466-50-03 Date: Febmary, 2004 //// I SHEAR ENGINEERING CORPORATION 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 Fax (970) 282-031 1 www.shearengineering.com uj I� I� UU LLJQ OCc Cc `- a c 0 0 N Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 TABLE OR CONTENTS TITLE PAGE VICINITY MAP TABLE OF CONTENTS I. INTRODUCTION II. GENERAL LOCATION AND DESCRIPTION A. PROJECT LOCATION B. DESCRIPTION OF PROPERTY III. DRAINAGE BASINS AND SUB -BASINS A. MAJOR BASIN DESCRIPTION B. SUB -BASIN DESCRIPTION IV. DRAINAGE DESIGN CRITERIA A. REGULATIONS B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS C. HYDROLOGAL CRITERIA D. HYDRAULIC CRITERIA V. DRAINAGE FACILITY DESIGN A. GENERAL CONCEPT B. SPECIFIC DETAILS - DETENTION POND C. SPECIFIC DETAILS - OPEN CHANNELS D. SPECIFIC DETAILS - FUTURE BOX OPTION VI. EROSION CONTROL AND WATER QUALITY A. GENERAL CONCEPT B. SPECIFIC DETAILS - WATER QUALITY POND C. SPECIFIC DETAILS - EROSION CONTROL MEASURES D. EROSION CONTROL SECURITY DEPOSIT VII. VARIANCE REQUEST A. DETENTION POND FREEBOARD VIII. CONCLUSIONS A. COMPLIANCE WITH STANDARDS B. DRAINAGE CONCEPT IX. REFERENCES 1 1 4 4 4 4 5 5 5 6 6 6 6 7 7 7 8 9 9 10 10 10 I1 11 12 12 12 12 12 13 2 ' Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 APPENDIX I - DRAINAGE CALCULATIONS APPENDIX II - CHARTS AND FIGURES ' APPENDIX III - EROSION CONTROL APPENDIX IV - STUFFER ENVELOPE 3 Final Drainage and Erosion Control Report for Eastgate P.D.P. ' Project No. 1466-50-03 I. INTRODUCTION ' 1. This report presents the pertinent data, methods, assumptions, references and calculations used in analyzing and preparing the final drainage and erosion control ' design for Eastgate P.D,P. ' II. GENERAL LOCATION AND DESCRIPTION A. LOCATION 1. Eastgate P.D.P. is located near the center of Section 18, Township 7 North, Range 68 West of the 6th P.M., Fort Collins, Colorado. ' 2. More specifically, it is located on the east side of Montgomery Street approximately 250 feet south of the intersection of Riverside Avenue and Montgomery Street. 3. Eastgate P.D.P. will be a Replat of Tract B, Replat of Tract A, Eastgate, First ' Filing. Tract B was designed primarily as a detention pond according to the design prepared by James H. Stewart & Associates in 1978. ' B. DESCRIPTION OF PROPERTY ' 1. Historically, this site exists in the Replat of Tract "A", Eastgate, First Filing. Within in this existing development, Eastgate P.D.P. is Tract `B." 2. The lots bordering Riverside Avenue have been zoned `Employment," according to the City of Fort Collins Land Use Code. The lots within the Replat of Tract "A" Eastgate, First Filing, not bordering Riverside Avenue are ' zoned low -density, mix -use neighborhood. 3. In the historic condition, a detention pond exists within this project site and services a portion of the property for the Replat of Tract "A" Eastgate, First Filing. ' a. Historically, approximately 1.82 acres contributes to this detention pond. b. No water quality is provided for the contributing area for the detention ' pond. c. This detention pond has a 12" RCP acting as the outlet. d. Eastgate P.D.P. has a net area of approximately 0.77 acres. 1 4 Final Drainage and Erosion Control Report for Eastgate P.D.P. ' Project No. 1466-50-03 4. In the new developed condition, a portion of Tract B will be regraded to ' provide space for a building pad for a four-plex townhome unit. a. There will be 2.63 acres contributing to this detention pond in the developed condition. b. Water quality will be provided in the developed detention pond. c. The release rate from the developed detention pond will match the release rate from the historic detention pond. III. DRAINAGE BASINS AND SUB -BASINS ' A. MAJOR BASIN DESCRIPTION 1. The site is located within the Spring Creek Basin as defined on the City of Fort Collins Master Stormwater Basin Map (See Appendix II). The City has completed updating the master plan for this basin. ' 2. Spring Creek is the major watercourse that flows from Spring Canyon Dam at Horsetooth Reservoir to its confluence with the Poudre River. ' 3. In accordance with the City of Fort Collins Conceptual Review Team notes on October 6, 2003, there is a possibility of master drainage improvements along ' the east side of Montgomery Street. This design will not inhibit the future possibility of these master drainage improvements. ' B. SUB -BASIN DESCRIPTION ' 1. A portion of the Eastgate development slopes towards the detention pond. a. The pond was initially designed in 1978 to meet City of Fort Collins storm ' drainage criteria current at that time. b. The pond will be redesigned and expanded to meet current City of Fort ' Collins storm drainage criteria and water quality requirements for the actual developed area currently contributing to the pond. ' c. Historically, there is 1.82 acres contributing to this detention pond. 2. Within the Replat of Tract "A" Eastgate, First Filing, Lots 2, 6, and 7 through ' 16 are developed. Lots 1, 3, 4, and 5 are not developed. These are commercial lots. 5 ' Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 ' a. The pond will be designed to accommodate a majority of Lots 1, 3 and 4 ' fully developed with a employment district (E-D) use. 3. Referring to the Historic Drainage Exhibit, there are 1.82 acres contributing to ' design point "h." Portions of Lots 12 through 17, which are zoned low - density, mix -use neighborhood, contribute to this design point. Also, a small portion of Lots 1 through 4 and a portion of Lot 5, which are zoned ' employment district (E-D), contribute to this design point 4. Referring to the Drainage and Erosion Control Plan, the same area contributes ' to the detention pond as delineated in the Historic Drainage Exhibit. However, sub -basin D2 was delineated to determine the amount of runoff in the swale along the south side of the proposed four-plex townhome unit. IV. DRAINAGE DESIGN CRITERIA A. REGULATIONS I. Design Criteria from the City of Fort Collins Storm Drainage Design Criteria Manual and options for storm drainage improvements discussed with the City of Fort Collins were considered. 2. Water quality control measures and erosion control criteria were considered ' from the Urban Storm Drainage Criteria Manual by the Urban Drainage and Flood Control District. ' B. DEVELOPMENT CRITERIA REFERENCE AND CONSTRAINTS t. The surrounding areas are completely developed, except for a few lots along ' Riverside Avenue. 2. All grading along the north, south, east, and west property lines will match ' existing grades. 3. Water quality provisions are required for and within the limits of this site. 4. Additional detention will be provided in order to restrict release rates from the site to less than or equal to historic release rates and to account for the water ' quality control volume. C. HYDROLOGICAL CRITERIA 1. The Rainfall -Intensity -Duration curves for the City of Fort Collins were used (Figure 3-1, attached for reference in Appendix II), in conjunction with the 6 ' Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 "Rational Method" for determining peak flows at various concentration points. t The Rainfall Intensity -Duration -Frequency Table was used in conjunction with the Rainfall -Intensity -Duration curve, which provides the exact same data (see Appendix II). ' 2. The 2- and 100- year stones were analyzed in accordance with Table 3-1 of the City of Fort Collins Storm Drainage Design Criteria Manual for ' commercial sites. 3. After coordinating with the City of Fort Collins Stormwater Department, the ' nmoff coefficients for areas zoned employment district (E-D) or low -density, mix -use neighborhood will be 0.85 and 0.60 respectively. ' D. HYDRAULIC CRITERIA 1. Open channel capacities are based on the Manning's Equation. The ' Manning's coefficient is in accordance with the City of Fort Collins Storm Drainage Criteria Manual. Haestad Method Flowmaster v7 was used in the calculation of storm sewers and channel capacities. V. DRAINAGE FACILITY DESIGN ' A. GENERAL CONCEPT 1. The historic flow patterns will be maintained with the development of this site. In developed conditions, stormwater will be conveyed through the site via ' a combination of overland flow, swales, and gutters. 2. The existing detention pond will be improved to provide a building area along ' Montgomery Street. a. This detention pond was designed as part of Eastgate P.U.D. prepared by ' James H. Stewart & Associates in 1978. A drainage report was not available. ' b. This detention pond will be adequate to detain the 100-year storm for the contributing area. ' c. In addition to detaining the 100-year storm, water quality will be provided with this development. 7 ' Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 1 ' B. SPECIFIC DETAILS -DETENTION POND t. The detention pond is located in the central area and in the western portion of ' Eastgate P.D.P. 2. The release rate from the detention pond will match the 2-year historic runoff, which is 1.20 cfs. Historically in a 100-year event, the detention pond restricts the runoff to the capacity of the 12" RCP, which is obviously greater than 1.20 cfs. However, to conform to the City of Fort Collins Criteria, the proposed ' detention pond will release at the 2-year historic runoff. 3. The total volume provided historically is 0.45 ac-ft. The total volume provided in the developed condition will be 0.73 ac-ft. 4. The size of the detention pond will be built to the following specifications: ' a. The detention pond will have volume of 0.45 ac-ft (19436 c0. This volume incorporates the water quality control volume of 0.07 ac-ft (3066 ' CO. b. The detention pond has a 100-yr water surface elevation of 4840.15 ft. c. The top of the bank for the detention pond has an elevation of 4841.00 ft, ' which will provide 0.85 ft of freeboard. A variance is being requested for this freeboard. ' d. For additional specifics, please see Detention in Appendix I. 5. The release rate of the detention pond will be built to the following ' specifications: a. An outlet stricture will be located at the eastern corner of the detention pond to control release rates and ponding elevations. i. On the northwest side of the outlet structure, a metal plate will be ' placed to provide the proper release rates for water quality. Another metal plate will be placed inside the outlet structure to release the historic 2-year release rate. ' ii. The outlet pipe from this structure will be the existing 12" inch RCP pipe. ' b. The release rate from the pond is restricted to 1.64 cfs. P, ' Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 ' i. The release rate is controlled by a 6 '/4 inch diameter orifice (See ' orifice release in Appendix I). This orifice plate will be placed inside the box of the outlet structure. ' ii. The release rate is controlled by two (2) orifices for the water quality control pond. There will be one 3/4" orifice and one 5/8" orifice, which together will allow a 40-hour drain time release of 0.021 cfs. ' c. In emergency situations with the detention pond being occupied while a 100-year storm occurs, the top of the berm along the eastern side of the detention pond provides an emergency overflow weir. The overflow will be conveyed historically towards the east. ' i. The top of bemm has an irregular height ranging from 4841.04 to 4842.00 ft and has an approximate 49 ft width. ' ii. The water surface of 100-year storm passing over this berm is 4841.66 ft. This 100-year storm is 15.04 cfs flowing at a depth of 0.62 ft (See detention in Appendix I). t6. For further specifics, please see detention and water quality volume calculations in Appendix I. C. SPECIFIC DETAILS -OPEN CHANNELS ' 1. Along the south side of the proposed building, an open channel will divert runoff into the detention pond. ' 2. This open channel will have a depth of 0.49 ft, while conveying the 100-year runoff rate of 2.69 cfs at this design point d2. This channel meets the 1 ft of ' freeboard requirement. D. SPECIFIC DETAILS- FUTURE BOX CONDITION ' 1. Along the west side of Eastgate P.D.P., there is an existing 35' drainage easement. This easement is for a possible future master drainage infrastructure which would consist of a trapezoidal swale. This swale would have 4' bottom width, 4:1 side slopes, 35' top width, and a longitudinal slope of 1.4%. ' 2. Haestad's Flowmaster v7 was used to determine the capacity of this trapezoidal channel with one foot of required freeboard. The capacity of this channel under these defined conditions is 336.09 cfs. ' 3. In order to have the future option to convey this flow past Eastgate P.D.P., the equivalent box culvert was determined to be a 2'x10' reinforced concrete box 9 ' Final Drainage and Erosion Control Report for Eastgate P.D.P. ' Project No. 1466-50-03 culvert. It has been determined that this development will not prevent this box ' culvert from being implemented with a master drainage infrastructure design. 4. For additional information, please see future box option in Appendix I. ' VI. EROSION CONTROL AND WATER QUALITY A. GENERAL CONCEPT ' 1. Erosion control measures are specified on the Drainage and Erosion Control Plan. ' 2. Maintenance of erosion control devices will remain the responsibility of the contractor and the owner until the project is complete. ' 3. A water quality pond will be constructed in the east corner of the site within the limits of the detention pond. ' B. SPECIFIC DETAILS- WATER QUALITY POND ' I. The water quality pond will be located in the base of the detention pond for this site. ' 2. The water quality pond will be built to the following specifications: a. The water quality pond will have a volume of 0.06 ac-ft (3066 cf). ' b. The water quality water surface elevation is 4838.80 ft. c. This is based on a resultant impervious in the property of greater than fifty percent (67.19%). ' 3. The release device for the water quality pond will allow a drain time of 40 hours and will be built to the following specifications: ' a. The release rate will be 0.0213 cfs. b. This release rate will be controlled by two (2) orifice holes placed ' strategically in the metal plate on the northwestern side of the 2'x4' box in the detention pond. i. There will be two rows of orifices which will be set four inches (4") apart. 10 Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 ii. The bottom row will consist of one'/4" hole set on -center. ' iii. The top row will consist of one 5/8" hole set on -center ' 4. A water quality outlet device is specified in the plan set, A detail is provided on the detail sheet. 5. A US Filter Stainless Steel well -screen will be provided in front of the water quality orifice plate. This screen will have the following specifications: i. Screen #93 VEE Wire Slot Opening 0.139. ii. Support Rod Type #156 VEE iii. Support Rod, On -Center, spacing = 1/4" iv. Total Screen Thickness = 0.31" v. Carbon Steel Frame Type = 3/8"xl.0" flat bar ' 6. For further specifics, please see water quality control in Appendix I. ' C. SPECIFIC DETAILS — EROSION CONTROL MEASURES ' I. The following temporary erosion control measures are specified on the Drainage and Erosion Control Plan: ' a. Wattles in the swales. b. Wattles used for orifice plate protection. ' 2. The following permanent erosion control measures are specified on the Drainage and Erosion Control Plan: ' a. Seeding of the open areas, including the detention pond. ' b. Water quality control pond in the base of the detention pond. I The erosion control deposit letter is attached in Appendix III. ' D. EROSION CONTROL SECURITY DEPOSIT ' t. An erosion control security deposit is required in accordance with City of Fort Collins policy. In no instance shall the amount of the security be less than $1000.00. 11 Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 2. See the Erosion Control Security Deposit Requirements document located in Appendix III. 3. The erosion control security deposit is reimbursable. 4. The erosion control security deposit is equal to $1000.00. VII. VARIANCE REQUEST A. DETENTION POND FREEBOARD I. According the City of Fort Collins Storm Drainage Design Criteria Section 9.2, one foot of freeboard is required for detention areas. This report is requesting a variance for the 0.85 feet of freeboard in the detention pond for Eastgate P.D.P. VIII. CONCLUSIONS A. COMPLIANCE WITH STANDARDS 1. All drainage analysis has been performed according to the requirements of the City of Fort Collins Storm Drainage Criteria Manual. 2. Proposed drainage improvements generally conform to the recommendations of the City of Fort Collins Master Drainage Plan. 3. Proposed erosion control measures conform to the recommendations of the City of Fort Collins standards. B. DRAINAGE CONCEPT 1. The proposed drainage design for Eastgate P.D.P. is effective for the control of storm runoff with a considerable reduction in potential downstream effects. 2. The proposed drainage design for Eastgate P.D.P. will have no affect on City of Fort Collins Master Drainage Plan recommendations. 3. The proposed drainage design will release up to a 100-yr storm runoff at the historic 2-yr storm runoff release. 12 Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 IX. REFERENCES o City of Fort Collins, Storm Drainage Design Criteria and Construction Standards; March 1997 o City of Fort Collins, Erosion Control Reference Manual; January 1991 o City of Fort Collins, Land Use Code; January 9, 1999 o Urban Drainage and Flood Control District, Urban Storm Drainage Criteria Manual Volume 1; March 1969 o Urban Drainage and Flood Control District, Urban Storm Drainage Criteria Manual Volume 2; March 1969 o Urban Drainage and Flood Control District, Urban Storm Drainage Criteria Manual Volume 3; September 1, 1999 13 Final Drainage and Erosion Control Report for Eastgate P.D.P. Project No. 1466-50-03 Appendix I Drainage Calculations Runoff Coefficients Runoff Discharges Detention Water Quality Control Open Channel Future Box Option Project No. 1466-50-03 Shear Engineering Corporation 02/13/2004 Designer: SWT Eastgate P.D.P. 08:31 AM Runoff Coefficients 4J P U 'H 4a v 0 U 41 44 0 P4 Eastgate-Drainage Cover dU rn c 0 `0 a 0 a UO ma c 0 v1° 0i ' n 0 o Q � m ch v 04 a co 0 0 L r1 ri w y N y C N m r n'o a y Q N tq O L 1 O C_ n .H G Q o� OQ N co 04 jzj 0 0 00 0 c N h C) (L O O O O N o 0 0 O O O N O (00 in 0) (D O O O O O "i oo� 0 O O 01 0 0 o a 0 0 0 0 O � n h O O N N O O (n N N 0 G .H N ro W d I M� O N O to i z d E 0 �� o w >O d y > E o z 'vC-i-i um pJ.;s V of L° d0— U' 7 co�U L° OvaEi o .,i �� U. Project No. 1466-50-03 Shear Engineering Corporation 02/13/2004 Designer: SWT Eastgate P.D.P. 08:34 AM Runoff Discharges v N ra U Q 44 4-1 0 04 Eastgate-Drainage Cover o cc _a ' m C7 O O d 76 Vl f4 ' O O a, O O O � W 1 ' C O N a N O Cl! N a M O N h (0 ro N N (0W N ri v1 O S-1 coN it �o U1 ' `on a U � ro� U d ro N o U � 0)a c � v Q, V! (9 C L11 W ' co a) N L Q U) ro A u •rf ' •.Ni W x (q 41 O H C u 0 ato W x a m •�j O C m 41 O a C 'O Q N Q ==tEXI /f DRIVE OVER CURB GU_TTE_R AND °$PDEWALK/: _ _ N o� I I + ll I No r f i t G SITE DESCRIPTION ACTIVITY 06f11FIOM MEIN IIBEWA MUT SHIMETAIRY 5JEWOi It(ECRC WEADMID wiL WISIMICIGX. pM Lors PROPpyD SEWOIfE 0 W!M LLTMI6 1 CIEWIp µD SIDCXPEND Df iDPSM. 3 CY®➢t CIYdM. 5 X61HILL YIIMAYrNMD MM4 Q WILDING µO PMIDXO LgOiNL'IIOX Tutu EmWTFS Tofu SIIE IIEYD.0 ACRE 1XICAL D61111WO 91E AlIAND.II W[ETCEMS NO 9p6 D6LIWIXIN � NON$ IOFETItlN14 IILIFII ro WRf M MGXIOE WTA TMUL EIMIMD SdL MTA, ME 0 SOL E EESJIRO WE ATGX MASS AND WTRT VE4TAml P6]wm scuices witHA I. WILOMC WIERIYS. N6)R VENCIES. CDXCRETE MA91-gR AMCOMMIT ME XD Ggll $WME M RECOVEMM 'RATE% OUIEAIL lYA1RW: SPMXO CIEM SUMMARY OF DRAINAGE DATA DEVELOPED CONDITION WINIJUSIN (AµI Ano CCIO Os c100 O: crs) aim (m) Al 0.14 0.87 1. A2 0.In 0." 0.0 PER 111 0.06 0.81 0.14 02 o.01 0.95 1.00 010 o Cl 0.10 0.78 0. O.i3 0. CZ o.w OVAL 0.541. 0.08 O. 1-u m 021 IX 1 0.27 OM 0 0 S`OM ON , En m_mdb THE HOURS Mwl(MOMENTUM allw:Tm AN WALL A,11 mm,m � D ,cnwT, w.me : AN WD, (3) ALL r� 6:m�nxa zmxnxc vcj TO My HAND D��G ANTRALLED AT LEE APPERI ME AM THE CONSTRUCTION SEQUENSE AS AT IN THE APPROPERE PRAYANAT SAMEDULE. PETROLEUM PUMPS WAY �NT ME DEVELOPED KEPT ALSO AT SOPHOMORE FOR MONFUNE AND wlxEE��wmw comma PAMPER SHOWN HELP IRED FOR NA Smxniw o RAm AMr s`�.(`nu. xm or CALL BEFORE (A' AIR RACTED (STRIPPINGDKURTINNORMAL YOUDIGWHOM SEGETALSONE ON OTHER PERMANENT BARRED SYMBOL MAKE ART EATORPER By "Ara.h"LY RwwmmuixiI(AR CALL UTLJIY NCTDCATON •A DATA noUPw cSEc. CEN1W OF COLORA00 AT nDA oL/mDREAFExo ATE X IMnAL1[D. Oars Ov u wO.m 1-800-922-1987 (�� "ImF wu iXL M („KW) ONS g (v) BE w4CCho .I. wONT IT EARTHEMry (x) x[RAn AFTER WARMHEARTED MIT EASTMAN' ON omia LEEmmxum bLAWPERFLA CE w ry ) W IIM I PART FARE 91 WE AS ALL THE SUMMARY M�� OWNERS RUPERT. en MST, ME SEE HAS SU�xm WA REMOVED CD AS ev HE mmaSBEEN OTEREM PAST MY SURSOMMI FOR Til TEAM UP AND REMOVAL OF ALL EMMlRES wrsrm:crcx (v.) M cmm.crzR .MALL wwnumY FEAR UP ourNAMEPLATE MANYWRIENTILY DEPTEDEM ON HANDED STREETS. ADEFINJUS. UP OTHER ONTO RATHER Of WAY, AND HATE PLAY NTRAI RED MUKABI ARE T THE FAR DP ow rwxc DAY w ER SHALL AT EMOSED AND [ASSETS AT IN A M�R ADD AMON BET AN I TO CAUSE HUR sA.nx wUT xU RD. EEwR SHALL "DATE AN (11) EAST IN w MAE E,T) HERAPPY DEALT MY PROPUTED OWN s�L SSMALL BE :ey AFTER THAA`T, of o1rs SILT AMYwxD. (I2) n AT MILL ME CALLEAMEET OPEN OF THRIFT AND eomL FEWERcWA NATIONWIDE OVER TO THE cUrv/cwn OR n on BEET) p1owc¢z OEURE SET ONSIONANCE AND EQUARAME) PERMIT XL( �) MY My PROUTMANT UP MANTANNATED MUTER LAW CM�� ARE, POLLI INCLUDE, BUT ARE NOT MANOR TO DWILSON "rtomv+cR � (WEREFF THEI WASHOUT C�� BE AND TEAS (w. WASTE ME DEVELOPER WALL AT ALL TAPE TAKE WHATIMER MEASURED ANY NECESSARY HE ASSURE ME BETTER CWHANNINt ART DMAKEW. STATE,SAWARY AND TmExuOPERATIONS W¢ RANT THE AREA PLANT BE CONSTRUCTED TRY BE M CONTAIN WASPAPPAT PARENT ARE LOOKED AT LEAST FULL EM FEET AWAY TRUMP My "WANT DJAFAI 'CONTEMPORARY HARRY 'TERRITORY, BE ACTIVITIES THE CONCRETE WAYLATUT PART MLL WE OFFSET AND MUTANT THEANKNO) OF w ME WAS vu¢AT NOT BYBAY F EWE (:5)TO ExNTAWARE DO Of ME FOLLOWED"TI CONma alasM HE ASTUALED 00 UAINTANE MET THE UPS AM RAW [ TRasw Tama mM[attt (wrtxwE FLY rs ux win �i Ou (.) ARCmT rfwwTuw"` (W) aXu Lv.W(5 X Ann). pna as .MMm WXMwTc.+�C"V M a../w „DEBATE GRAPHIC SCALE 220 AD "�.HID4°XCT°'UP x EEFT ) MY.wTm MY AID t III AN 20 2 1/ wRom MsMA. sgnu w.n RAMADA AM aY^w snvgY AM AWv:sti v AM xtliK4lw rto:mm A m. q fryti. MING LEGEND rw®ew WANT V /�� MITmu -_____ av®ua mxew. mx NAMErvamn. Al ." ""L e.....m.. mD� w,m ass un WASTEDP-1 (x,Mfl X �®'Pw: ® nxxwa: xmvq rnoom wx wamm WAR RANNAMPAWE PAR THAN't PAN - �JTHAN Hand SEMY NOW SON (SENTI EMERY. THAI �III VERGETATIVE PAR SAW MEMS; OFFY N Ci I Fm1 CgnDv. Culumeu MLm Pux APPROVAL PRo n: xn,.., vT y�.�w . CHI RY: .+.. w.w...I.. MRD o-x CHECKED RY: vvmvel.r wear hI. CHECKED EY: r.b a yUnem.. fam MECKED RY: CHECKED III ;•,,.:. M , r. - Ld \\ GENE¢AL NOTBS ��T 1 1 X'LfWLdML:.E[E✓ /NdCATEO TMWLY- 635- AEG N/N 6LEV T6 1bP t l l 3 A W.,ff er caVeYrrs' Pa/udriov xuLL 4502 a \\ L QPTEWr/ON ✓l [&MC' REM//<EO � 95/T3lF �APW/LYO. DJCNO - y .alaT6 O ... 9 7'1 !<S : c9re•0 9.0 .. .+,y4 rc„",'+' v 1 BM: NE(G A?CiJ Mour6 M�Yv a03alr ���� < !L? 5tcwIr Attu WEsr v5 fT AP4/ 00 HMALntr rEP �;F S rM "Aow jstwP AT mecwIa'/vx~ 3lGe! A/d/f I' �� ` [P✓SAUOdML IEUT ;F OF S Jrdm aO s /.{y. 4IIOWIbIM �\ pp V_y[.6* I ' \\`\� LIP4/A/I6E SWALE , 2 ow Al Ail: e tito It klL 419 I y '� ( �,nTF 4 ` • f., N I ( a �� "a� � ry�i. x'ARE4 -1.� v 0. {T. \!� •4/a- � �\ � � \ t . ski o r AMY N\1 \ .�5 \n il. III � / \\ ,llrsRi<!q I, 11 fl l \ -iMi.. II 1p1�"' /iirluri urges_ pl fy l�,i "y4'F 1 41&14I COW y(d Sale _1.._ I: w • ..�'{F PniCiN S Wr- ' ' 3