HomeMy WebLinkAboutZ-6596-A Map 920 10 0 20 40
SCALE
STORM WATER DETENTION CALCULATIONS
1. Area of improvment: 0.46 acres
2. Assume minimum time of concentration
of 5.0 minutes due to size size and length
of improvement.
3. Intensity: 8.5 in./hr. (25 year event)
4. Pre -developed run-off coefficient (C value): 0.53
Post -developed run-off coeffiecient (C value): 0.72
5
I*
7.
8.
9.
10.
Pre -developed flows (Q):
Q(25): (0.53)(8.5)(0.46) = 2.1 c.f.s.
Post -developed flows (Q):
Q(25): (0.72)(8.5)(0.46) = 2.8 c.f.s.
Total allowable flow (pre -developed, Q25)
Undetained Discharge = 0.83 CFS
2.1 c.f.s.
Allowable discharge from pond = 2.1 - 0.83
Actual volume of discharge from detention =
= 1.27 cfs.
1.25 cfs
MAXIMUM CROSS -SLOPE
ALONG APRON BETWEEN
RAMPS IS 2%
11. A 13" wide opening in the curb will restrict the
post developed flow for the 25 year design storm as required
to pre -developed flow conditions. The 50 and 100 year
events will overtop the curb and flow behind the building
into the existing stream channel.
LOT 1 REPLAT
SOUTHALL SUBDIVISION FIRE HYDRANT
HEADWALL
LOT 476
PLEASANTREE
FIRST ADDITION
T 1 RE_PLAT
ALL SUBDIVISION
CRETE
WALL
!K FENCE
1.91
5. 423.61
WATER METER
GENERAL NOTES
1. THE LOCATION OF THE EXISTING WATER AND GAS UTILITIES ARE
BASED ON RECORDS FROM SAID UTILITY COMPANIES AND ARE
HORIZONTALLY FIELD LOCATED ONLY. THE CONTRACTORS SHALL
BE RESPONSIBLE FOR DETERMINING ACTUAL LOCATION.
2. CONTRACTOR TO UNCOVER AND MARK UTILITY LINES BEFORE CONSTRUCTION.
3. CONTRACTOR SHALL BEAR ALL RESPONSIBILITY AND COST OF REPAIR
OR REPLACEMENT OF EXISTING UTILITIES, DAMAGED OR INTERRUPTED
AS A RESULT OF THIS CONSTRUCTION PROJECT.
4. CONTRACTOR SHALL NOTIFY THE PROJECT ENGINEER AND THE
OWNER OF ANY DAMAGED OR INTERRUPTED UTILITIES IMMEDIATELY.
5. CONTRACTOR SHALL NOTIFY PROJECT ENGINEER PRIOR TO BEGINNING WORK.
6. ALL AREAS WITHIN THE PARKING LOT ARE TO RECEIVE A GRAVEL
BASE TO PROVIDE EROSION CONTROL IF WORK IS NOT PROGRESSING
IN AN ORDERLY MANNER. A RATE OF 135 TONS/ACRE IS TO BE
APPLIED WITHIN TWO WEEKS OF FINAL GRADING.
7. ALL AREAS NOT WITHIN THE PARKING LOT ARE TO RECEIVE LOOSE STRAW
TO PROVIDE EROSION CONTROL IF WORK IS NOT PROGRESSING
IN AN ORDERLY MANNER. A RATE OF 1.5 TONS/ACRE IS TO BE
APPLIED WITHIN TWO WEEKS OF FINAL GRADING,
8. CONTRACTOR WILL CONTROL AND PREVENT OFF-SITE TRACKING
0 WATER VALVE OF CONSTRUCTION RUNOFF AND SEDIMENT TO ADJACENT PROPERTY
AND PUBLIC ROADS.
v MANHOLE
9. CONTRACTOR IS TO PROTECT EXISTING STORM DRAINAGE SYSTEM
�Y UTILITY POLE I ACCORDING TO PROTECTION ILLUSTRATIONS PROVIDED.
0 LIGHT POLE
~C GAS METER
�- WOOD FENCE
---X-- CHAIN LINK FENCE
--3'=--w- EXISTING UTILITY LINE
OHE = OVERHEAD
ELECTRIC
SS = SANT. SEWER
PROPERTY DESCRIPTION
TRACT C-1, RAINWOOD FOREST, LITTLE ROCK,
ARKANSAS AS RECORDED IN PLAT BOOK 36,
PAGE 92, IN THE OFFICE OF THE CIRCUIT
CLERK OF PULASKI COUNTY, ARKANSAS.