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HomeMy WebLinkAboutRAMADA LIMITED SUITES PUD -- PRELIMINARY - 16-96A - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTC Runoff from the detention ponds will be to the existing storm drain manhole at Boardwalk Drive and South Mason Street. Emergency overtopping of Pond 1 will be north to Pond 2 in the parking area. Overtopping of Pond 2 will be North in the parking area to Pond 3. Overtopping of Pond 3 and 4 will be to South Mason Street. Phase 2: Lots 3 and 4: A 14,00 square foot commercial building is proposed on Lots 3 and 4 along with the parking, access drives and landscaping. The shared access road on the North of this site will be constructed with Phase 1. The shared access drive on the South side was constructed with the existing commercial building on Lots 5 and 6. South Mason Street is constructed along this site, except for the four foot walk to be constructed with this site. This phase is divided into four subbasins with detention ponds. All runoff from the ponds is directed in a piping system to the existing McClellands/Mail Creek storm drain system at Boardwalk Drive and South Mason Street. Emergency overflows from theses ponds will be in the parking areas and flow north to Phase 1. The City standard maximum depth for the 100-year high water line of detention ponds is 12 inches. A variance is requested for this projects ponds 2 through 8. The finished 100-year depth of these ponds are: Pond 2, 1.1 feet; Pond 3, 1.3 feet; Pond 4, 1.5 feet; Pond 5, 1.5 feet; Pond 6, 1.3 feet; Pond 7, 1.5 feet and Pond 8, 1.5 feet. EROSION CONTROL: The sequence of construction for this project will be in two phases. Phase 1, being Lots 1 and 2 will be overlot graded. Next the foundation and utilities will be constructed; then curbs, parking, and walks; then asphalt and finally the landscaping. The phase is scheduled to be completed early 1997. This site is in a moderate to high rainfall erodibility zone. A silt fence will be constructed prior to construction as shown on the plans. After the storm drain inlets have been constructed, straw bales will be place around the inlets and remain in place until the site is completed. This site is in a moderate wind erodibility zone. The buildings and curbs will be constructed as soon as possible after overlot grading and along with the said silt fence will help control wind erodibility. The erosion control cost estimate for Phase 1 is $1305. A beginning construction date for Phase 2 has not been scheduled at this time. Construction sequence for Prase 2 will be similar to Phase 1. A erosion control schedule will be required prior to beginning of Phase 2. Because of possible price changes the cost estimate for Phase 2 will not be included with this report but will be required prior to construction of Phase 2. (2) FINAL DRAINAGE AND EROSION CONTROL REPORT FOR LOT 1 AND 2, GARTH COMMERCIAL PLAZA EXISTING SITE The proposed site is Lots 1, 2, 3 and 4, Garth Commercial Plaza located in the Northeast''/a of Section 35, Township 7 North, Range 69 West of the Sixth P.M., Fort Collins, Larimer County, Colorado.. The gross site area including the West one-half of South Mason Street is 2.86 acres. This project is in the City of Fort Collins "McClellands/Mail Creek Drainage Basin". The site is bounded on the East by South Mason Street which is constructed; on the South by Lot 5 of this Subdivision (Lot 5 is developed); on the West by the Burlington/Northern Railroad; and on the North by an undeveloped site. The North site is a wetland area and will probably not be developed. It is not owned by this developer. There is no offsite runoff from the North or East or South onto this site. A part of the Railroad right-of-way flows to this site from the West. This sites runoff is Northeast at about 1% slope. There is and existing 30 inch storm drain system in Boardwalk Drive and South Mason Street North of this site. The outlet for this system is Mail Creek. The allowable discharge has been previously established at 0.5 c.£s. per acre by the McClellands/Mail Creek Master Plan. DESIGN CRITERIA: The rational method will be used to determine the developed site initial and major storm runoff Detention for the site will be based on the 100-year storm less the allowed release rate of 0.5 c.£s. per acre. The mass diagram will be used to determine the required detention. All calculations and design consideration are in accordance with the City of Fort Collins Design Criteria Manual, except the historic 2-year storm will not be used for the release rate. DEVELOPED STTE: Phase 1: Lots 1 and 2: A Ramada Limited Suites is proposed on this site. It will be a 66 unit three story building with parking, access drives and landscaping. A shared driveway with Lot 3 on the South side of this site will also be constructed with this project. South Mason Street is constructed and flows north to an existing inlet about 200 feet North ofthis site. This phase is divided into six subbaMns. Four basins will have a detention area. Runoff along South Mason Street South of our project will be routed through this projects system in exchange for the runoff along South Mason Street East of our site that flows North and will be undetained. Also a small undetained portion of this site will flow to the North as it historically does. This is Subbasin No. 9. This basin is a part of the "wetlands" area and is to be left undisturbed. (1) r i i i VICiNi rY MAP SCALE-/"=/000' --gyred Ce It Monroe Ave E' $ _ c il. ¢ Ntj T LL a . IV¢ d Hs E 1 OTN vi 2oAD Ave.Star Dr LL do�nila Ave. 0 e� z�ONQ I a, Ada o Ave. ,lasrnuri a b . r ] Leeward CI r 51olie o J �U 7 I V i c n,, p Dellrll$pl �� > ``\ 86*1 1p Cl. A Pe ble n °urn �� �u; S TL g o �n0fn Winler '� C 1. u \ —(g9 \� cl. o AI ' , I C lb Ord l; ` or°r1\. �� r c (� rrCwt Ur. if o \L° / 4 best CI Dr. cF '•; , kObasll SI. � Boardwalk I ( c - Ili h"45 Ln. .f �d�.nrH vaG/. rural ' 5 uv d g - 4 a o I J��• forin 1. eesr W rs Greal Plains CI •rl� ` I ,� r (D,�9 u c .s r mlS ° V lroIL u n pkvr r`' u �' 0 e w n e ;aril emanl 1-a rn lma 0 r�r I iE ao 8 �. o� irautn an PhWy YI �+ ` 3 ►— i OU v n ear ree r t Thrasher c c ' 1 ; I Srvsl c 3 S1, c ` N-rARE6r- l CI. 'd D C1� I in Tbvilion Lm � o �V L� ,rpa° i l" o Owl Chu or j „ C1. Cl. !- .��d Kensln n c l Iu %Or. u 'vor towhee SI. 1` p I~ `.. f�yRRfilcZNjr,l F-OAV Table of Contents A Vicinity Map B & C Text of report la - 4a Erosion control calculations 1 - 51 Drainage calculations Pocket Lots 1 & 2 Grading, Drainage & Erosion Control Plan Lots 3 & 4 Grading, Drainage & Erosion Control Plan I I I I I I I ' I I STEWART&ASSOCIATES Consulting Engineers and Surveyors July 8, 1996 W. Basil Hamdan Storm Water Utility City of Fort Collins ' P.O. Box 580 Fort Collins, CO 80522 IDear Basil, Lots 1 through 4 of the Garth Commercial Plaza are to be constructed for a three story Ramada Limited Suites on Lots 1 and 2 and a commercial building on Lots 3 and 4 with parking, access roads and landscaping. This site is in the City's "McClellands/Mail Creek Drainage Basin". This project will be developed in two phases. The Ramada Limited Suites will be Phase One. All design and calculations within this report are in compliance with the City of Fort Collins Storm Drainage Design Criteria and Construction Standards. if you have any questions regarding the attached report and calculations, please let me know. Sincerely, James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522 970/482-9331 Fax 970/4824382 FINAL DRAINAGE AND EROSION CONTROL REPORT IFOR LOTS 1 THROUGH 49 GARTH COMMERCIAL PLAZA I LOCATED IN THE MCCLELLANDS/MAIL CREEK DRAINAGE BASINS PREPARED FOR GEORGE HOLTER July 891996 PREPARED BY STEWART & ASSOCIATES, INC. 103 SOUTH MELDRUM STREET FORT COLLINS, COLORADO 80521 970/482-9331