HomeMy WebLinkAboutMELDRUM/MYRTLE 4-PLEX - PDP - 13-01 - SUBMITTAL DOCUMENTS - ROUND 2 - DRAINAGE REPORTC3)
On -site stormwater detention and extended detention for water quality will be provided for
Basin II in the East parking lot and the landscape area North and West of the proposed four-plex.
EROSION CONTROL:
A sediment trap will be placed in the detention pond until the water quality structure is
completed. A silt fence will be placed along the property line North of the four-plex.
The stormwater runoff calculations and the detention and extended calculations and the
erosion control calculations are a part of this report.
This drainage report and the design of the drainage system are in compliance with the City
of Fort Collins Storm Drainage Design and Criteria. If you have any questions regarding this report,
please call.
Sincerely,
62" .� a.
Richard A. Rutherford, P.E. & L.s.
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STEWART&ASSOCIATES
July 9, 2001 Consulting Engineers and Surveyors
Mr. Basil Harridan
Stormwater Utilities
City of Fort Collins
P.O. Box 580
Fort Collins, CO 80522-0580
Dear Basil,
The following is the final drainage report for Lot 8, Block 96, Harrison's Addition to the City
of Fort Collins, Colorado. The address of the site is 600 and 604 South Meldrum Street. The area
of the site is 19,000 square feet. The site is in the Old Town Master Drainage Basin. The site is
bounded on the North by West Myrtle Street, on the East by an existing 20 foot alley, on the South
by an existing residence and on the West by South Meldrum Street. The site has an existing frame
house on the West 100.00 feet of the North half of Lot 8 and an existing brick house on the West
100.00 feet of the South half of Lot 8. The site is not in a flood plain of the Old Town Basin.
The owner is proposing to construct a four unit residential building on the East 90.00 feet of
M Lot 8. There will be four garages and four parking spaces constructed for the proposed Four-Plex.
The garages and parking spaces are accessed from the existing asphalt alley.
The front yards of 600 and 604 South Meldrum Street slope West from the houses to the East
curb of South Meldrum Street. The existing rear yards of the two existing houses slope from the rear
of the house to the existing alley. The existing alley slopes from South to North to the South gutter
of West Myrtle Street. ,
There is an existing curb inlet on the East curb and gutter of Meldrum Street at the
intersection. The South curb and gutter of West Myrtle Street flows East from Meldrum Street to
an existing curb inlet at the Southwest corner of Myrtle Street and Howes Street. The curb inlets
discharge to the existing storm drain in the center of West Myrtle Street.
The site is divided into two basins for the historic runoff calculations and the developed runoff
calculations. Basin I is from the front yard of the two existing houses to the East curb of Meldrum
Street. Basin I flows to the curb inlet at the northwest corner of Block 96. The area of Basin I is
0.107 acres. The historic runoff and the developed runoff for Basin I are the same. The two year
runoff rate for Basin I is 0.09 c.f.s.. and the 100 year runoff rate for Basin I is 0.40 c.f.s...
Basin II is the balance of the site from the front of the existing two residences to the East side
of the alley and from the South property line of Lot 8 to the South curb of Myrtle Street. The area
of Basin II is 0.527 acres. The two year historic rate of runoff for Basin II is 0.31 c.f.s. and the 100
year historic rate of runoff for Basin II is 1.48 c.f.s. The two year developed rate of runoff for Basin
110.58 c.f.s. and the 100 year developed rate of runoff for Basin II is 2.88 c.f.s..
James H. Stewart and Associates, Inc.
103 S. Meldrum Street • P.O. Box 429 a Ft. Collins, CO 80522
970/482-9331 • Fax 970/482-9382
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TABLE OF CONTENTS
1 Vicinity map
2-3 Teat of Report
4-7 Runoff Calculations
8-9 Detention Mass Diagram and Volume Table
10-12 Extended Detention
12-16 Erosion Control Calculations
17 Restriction Plate
18 Spillway Design
Pocket . Grading, Drainage & Erosion Control Plan
d
FINAL DRAINAGE REPORT
FOR
LOT 8, BLOCK 96, HARRISON'S ADDITION
OLD TOWN MASTER DRAINAGE BASIN
PREPARED FOR
ROCKY MOUNTAIN CONSTRUCTION MANAGEMENT
DULY 99 2001
74mm�Z
PREPARED BY
STEWART & ASSOCIATES
103 SOUTH MELDRUM STREET
P.O. BOX 429
FORT COLLINS, CO 80522
TEL. 970-482-9331
FAX. 970-482-9382