HomeMy WebLinkAboutRIVERSIDE JUNCTION PUD PRELIMINARY AND FINAL - 13 92 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTI
STORM DRAINAGE
AND
EROSION CONTROL REPORT
ADDITIONAL PARKING LOT
FOR
RIVERSIDE JUNCTION P.U.D.
PREPARED
FOR
POUDRE VALLEY HOSPITAL DISTRICT
PREPARED
BY
STEWART AND ASSOCIATES. INC.
MARCH 2. 1992
STORM DRAINAGE AND EROSION CONTROL'REPORT
RIVERSIDE JUNCTION P.U.D.
SITE LOCATION
The additional parking lot for Riverside Junction P.U.D. is a 1.55 acre
site located at the west end of Pennock Place in the Southeast I of the
Northeast I of Section 13, Township 7 North, Range 69 West.
EXISTING CONDITIONS
The north half of the site is a gravel school playground, and the south
half is a grassed pasture. The site slopes from southwest to northeast at
a 3.5 percent slope. The Emigh Lateral irrigation runs along the south (high)
side of the site. There is offsite flow onto the site from two—thirds of
an acre of gravel playground. The attached plan shows the area of offsite
flow contribution.
PROPOSED IMPROVEMENTS
A paved parking lot with concrete curbs and walks shall be constructed
on the southerly three —fourths of the site, and a detention pond shall be
constructed on the north one—fourth of the site. The detention pond will
be sized large enough to handle the runoff from the 1.55 acre site plus the
0.66 acre offsite flow, a total of 2.21 acres. The detention pond will be
seeded with low maintenance dryland grass, and the entire site will be
maintained by the owner.
The outfall from the detention pond will be into an existing overland
drainage path which drains north along the west side of the pavement and
curb behind Longs Drug Store. This drain path joins an existing drain Swale
from the west, and the combined flows are picked up by an existing storm
pipe which drains north along the west side of Longs Drug and Albertsons.
The plans indicate this pipe is 8—inch diameter where it begins at the south
end and increases to 18—inch diameter.
Calculations of the runoff, site release and detention volume required
and provided are shown on the attached computations sheets. These
calculations comply with the City of Fort Collins Storm Drainage Design
Criteria.
EROSION CONTROL
The detention pond shall be constructed, and the outlet pipe covered
with a gravel sediment filter during the site grading process. The parking
area will be paved, and the detention pond and bare ground areas will be
seeded with dryland grass and straw mulched. The site is in a moderate wind
erosion area, so the construction of the curbs and rainfall er4,sJon„control
measures will provide adequate wind'erosion controls. ���•��Q I.o�UB�ry'��,,�
s .
QZ�o �&\STEqq°o��.4i:
a o m
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Phillip Robinson, P.E. & L.S. =izo 4502 0"
e e. & 0000.0 e,.
4,4' ' j,ln'F' CO,`�P�.
AMPUTATIONS
Stewart& Associates, Inc. 214 N. Howes St. .,Ft. Collins, CO 80521 (303)482-9331
By: Date 3U Client: Foudre VC I Sheet No. 011e�e of
41,
Chkd By: Date- Project: pa rkl nc LQ- in ZVE !Z2 Sec. 173-7-6-7
Subject -5-hOLen Drainaa
7
0' 6 61 /4 C;i GI=10�3h I
TOTAL
e sire A REA
�0.
f2 C/V'� ro� 11 i ::-
f 2. Z) A
Pi's 6 0 �l 0Sde X Cl. -7 0'6 7 X- 0; + Ol-qd �T .' 6 7Y/
I 0- --
Pew 0 0.1 T
3
T<1 is� Fr!v,� r-
Z-
�zC_ + /�41LOw/'4 DLS rK E L E,�, 5 E)
�4 Is 75 S
= lZ r�ih T�/ba I> F 10 min i ..I
-V
0.77 6) 2�. z 13
OIL
ff
_7! 3 C4
VO L V M rZ.-, FOND
t_." 0 ume n 4- C' L/
445
ao it
3 1.4- 0
�9_ 7 6
C7"'er-
V TF L a a
p
0!
v; SL� ��~ i
3
It- T
C 0 r- r_V -S vv 1;
e/
vk_� 0 V,
+ It. 31 2-5
4/(
3�V
3 v
151 i's C; S
151, is 0 P�'
S Or I C,
COMPUTATIONS
Stewart & Associates, Inc. /214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331
By: P1 %C Date 97 Client: F0'U� re V ck 11 e*7 /45L> cd Sheet No. of �
Chkd By: - Date Project: PQFLK ns L(4- ih NF_ 14 17 -7-
Subject _ _ S_IV r-rn bra i n a �, P
RAINFALL PERFORMANCE STANDARD EVALUATION
--------------------------------------------------------
PROJECT.: STANDARD FORM A
COMPLETED BY: P ) JZ DATE: 3 Z 9 2—
----------- ---------------- ---- ------------------------------------
DEVELOPED ERODIBILITYI Asb I Lsb I Ssb I Lb I Sb I PS
SUBBASIN I ZONE --- (ac) 1 (ft) 1 (%) 1(feet) I
a
To7N L I Mvdera�e 1 3 zo I I I e 2.5
51TE
0
1--------------------------------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
HDI/SF-A:1989
TADI[ie:RY 1991
8-18 DESIGN C,-TERL.
EFFECTIVENESS CALCULATIONS
--------------------------------------------------
PROJECT:
COMPLETED BY: pJJ
Erosion Control
C-Factor
P-Factor
Method
Value
Value
-re- -oil ---------------
13are S
-------------
17 --aG,
1-00
TrQr.
Pa vie. wc1<<r.
6/ r%Oc{ g SCCcti'S
/.00
0.01
0
0.�0
1.06
/.0C/
MAJOR
BASIN
ToTA�
517E
SUB
BASIN
AREA
(Ac)
;
----------------
STANDARD FORM B
DATE: 3 2 2
Comment
Ale r7e on silt
---------------------------------------------
CALCULATIONS
--------------------------------------------
Pv,-14- a r--ea = I.00/ Ae-
j3are 9rovk = (%
SCCC;ftj ¢Mv1ck U.SS A-C
-t 6?.0Ox.5s -
FFF =(1 - o. 02 7X 0. s6),�
---------------------------------- --------------
DI/SF-B:1989
loci 8-19 f SIC I CR1773iI
II CONSTRUCTION SEQUENCE
PROJECT: Pa LO�-�i0erslr/ TVhe_- I( h P- V 14o5l,-7il a ) STANDARD FORM C
SEQUENCE. FOR 19 ` Z ONLY COMPLETED BY: DATE: 3 2 Z
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
MONTH
----------------------------
OVERLOT GRADING
WIND EROSION CONTROL
Soil Roughing_...
Perimeter Barrier
Additional Barriers
Vegetative Methods
Soil Sealant
Other cvY� f pvr^4
RAINFALL EROSION CONTROL
STRUCTURAL:
Sediment Trap/Basin
Inlet Filters
Straw Barriers
Silt Fence Barriers
Sand Bags
Bare Soil Preparation
Contour Furrows
Terracing
Asphalt/Concrete Paving
Other
VEGETATIVE:
Permanent Seed Planting
Mulching/Sealant
Temporary Seed Planting
Sod Installation
Nettings/Mats/Blankets
Other
A I/V1 I s I s I A I s 1 0 1 1 I I I
-------------------------------------------------------
STRUCTURES: INSTALLED BY MAINTAINED BY
VEGETATION/MULCHING CONTRACTOR
DATE SUBMITTED
HDI/SF-C:1989
APPROVED BY CITY OF FORT COLLINS ON
JAN ARY 1991 8-20 DESIGN CRITERIA