HomeMy WebLinkAboutDrainage Reports - 12/03/1999� I, - 4-1,., .I l, � ,;-- ,.,----`f� . ,,
"
1 ,.J�,tt',7 ." � , I . I 'y � �. , - .. 1. t . , � ,,,t-
. . I , , ,11 � - , . -
..,
I I ..fj. - ,1 -- - , -i., I � -,- I
- I I . I � , I
, I . I . " - - .1 I I � I I � .. - .
--,-,v,,'%1�
. - 11,
" ', 'it I I 1,)� I
1. e -,-. ... t.-, ,to
.-- .,,"* 'l,-i--,. ,i -,Yi,�i -4
�� -,- I "
I - ,. o�t -
.. '
.'.
I
. , l -, - �� I,
1 , " - , - t� .. .. .
- . :, -, .1. � I , , l � . I ,
* *
1,t-
1, - .
.I
I.; .. �.
.
,
.7
I.I-"It -,"
t 4,it , ,
'.- �,"�,-t- !�-,GI V4.;,I.�t.. t.O--- t,I. "i-t-P�.- '.1..,� � ,-�- ) ,I-- "t- � f i�.1. .- - 1
.1."4,
j! r,1,5 , f Iktj % : I .,
:1
, I -1,-,._.�. - ". , , , ":4�'. ? ,
� .,V,� V, - .1,-'' . .. .1.1. '. . . i.
- 1.1.11 , , 4, . ,
. - ll 11 , " - 1, - - -) ;
-x-, icy
� . . -�
"--�- - .
� ,
Jl.
., ".
. �. --- oi , k I "" .,*� I
- I 41, z ,- �,�.,,�:,e,, o � -."- l �'. , - -, ,-��,- *-. "
� I - � . I.'.' i'-.-.1 -,'-� -% FINAL DRAINAC
- �- t ,-- 1�, --, - - ... t'. 'I,..-
'. t , "� " �.-- ."I., - - ,,,� " It ". - . -.1" I t� -'.
.,'-----,- ..".. � - - -.1 11
-, I'... "., , ,
., --
1.".--,
..I;
"-,,,l-. ?,",.�.--%I, "-_
5
L
-1W', t -";
i 1- ,-,tr,,)I I ,
- IV I ( k ,.-
.-
�f>
,�-,iA o-
1
;-
',qt. -,.,." --I. -,,�...
"i,---,'--�-L--I .'1�--,V�. ,-,.,j1 I - 1�.-1-';-."-
.
-�,-I.y,-
.-�-"I,..-�, 'x
.
t�-1, ..,
'I�I
.
I"
,
-"4-
-,
,.
1�
�f
'��-�,1'-K.;.,,- p�4-o1-- �11M47]
- ',.Ill�-
Ulxtt�N�`i�,2,W,,,l5fO,.I "�t��
:�,r-,",t t-q-3 1ft-/t4-"
�,. . -IV 1 t,�',-a
� "r..,"t1
- j�--,,t,.�,-,,)
. - � ."�, 1-1 ,k'f I�,1,
.":1` �I
-- s;t
1I
1- ,t. 1. �
;�.' , ,. , , %:.. , �, .. ".. 1�
-...�..-, � -..,. �7.. , , -..�+
, -I-
.,-',
,-
-�'-, f
1O ; ,I.Y I , 1,"
1.. , I-," -
"..,
...�.<� . ... �.
I
1 s "-, ,
-11�1- '.� . j� . .- I", . .. . �-, , , �n,
,t%.-,,- 1-
�-,X I . �j :
l,
i .4Q, , t�$1",,f-,," ,-1 tI, ,i1-x,
,
�
, bit ; ,�It-,�,,.1, 9-. -
v" vI-,
I
I .I,
t.,�"- -!--- I. ,
.,1,
. ,, 1e ,-I,I ,I-
,1,�o
-- -
-,
"-
,I
} ., t
1 ' I- - .. . x I . J
I , I
"
, I, a :
,-
I
. � � �
�- - -, . , - -.,v . . . ".
� . . ,
It, �- - � " '; -� , ,- . , '. " A� - � � ; 7r,
. .- - I I ,- - , I 1, .. - I � r I - I .. � t, - . ,� � � tt � ,�
I ". ,
I
. I '. I -,. . .l , , -,,--
i t - - � . Z , k- I" � " I I
- :*t. ..- - � � , ,. . '�, , t. -,-� , - - .-. 1-�` ,.i- - � -
I
-
1, ? .,
.1
-1,
d�-,.-,iv-�,-S,-v- Vi-L�iti k.,_.;*,",-1----,.,--"�,j.I4�. ,"".%1I ",,��.-�- .1."..-7"tWC'--'-f�-t-�';.�,, -�-.,�T1-:�,C�,1---,- ,t,1-.-,- - -e t�.• i.v'.-,t-�i:-e-,I.,�Ay ..�t...,., VI ."-� .- -.,
11-"I,"
-� ,2
I1.v�,
-,1
,.
IZ.A
.
..,".l.f,1
,
.-.-�..
,I..........� - "
'
.�i
o ,,-,�v", , 1P, ,tv '',q'
yIF,,itI,,.I.9'i',,Vf"ItLW,, 11""1,, t ",l I h-I;,�;r
, lI, '1, -'.-Xt, C,� ,
'
- ZI,a. ..r4 �"-11,1"� t ;j�)."-�,r 11 ,..1
I,�t-x , $ f,N.11.`, 4w t ,(t I Ii
AND EROSION CONTROL - .",-',-, �`
\, , - Ti�
QWNHOMES..- ,
,..
".
-..
,i.
.,
T"F " t";,.
,
.'
jir!,,1�".T�,:,"v�-.eI "� z I"". . -
e,
ER CREEK, P.U.D,-'"T" r'1 . . .
V,-� , 4
,W,lV v%,L ,,- ,�,,tt.ttjv'"i1I� s
,-,"", i >,4 - , ", J. '?, V,x"rt-1,IN,1" j , � k A ,
1 ,�,iYJ,1Y"`, C';-,i" '"1 ,1t 11,lI , i �� , 1t t-
�.,i'vt"-"' ,} i V 1, ,,"r. �pI ,""
JA"JIvr j 1-tI y"?4I '," , , I
III
,-.".l1.-,-..--',5. ,'""-, �,� ,1,.1.1.," .:-'-,IzVl. it I-;-��
-�';-"
lI,
. -
..
,
,
-
,fi
-
--
,I.
-
I
,I
'I. ".A i't-. Vi,"",,i,A,'- t V,
- IIoIk-,. n-,3-, •,,, t
,. .14 �`"I ,
ry-Nz .. l-- 7
, .., - ,-d�,e t q, .�,% , , ,
� I,",VI i
I .,yS,?1117 A-� II,~ 1-
,--.-I""-l>,1-At.1 ,, 4. ,"',, ". w- 4t ,t,
y,-X ,t4"" W11 1tk-i1?rIS;V4-�111-k". I t 1" ",.1"e Ai F--,,,J-"-S ....., ,I, ,, ,�:"-�. -,-.v I
'y S-ry5"),, l,1,:�, ��1 ,b ,IV. I i-'1{1
*� ,p, t,-,.-,s,n #-��I -;,,"4.ve,1I ,i u ,,- "eiI
) t -�,I q L4 0i h` �� ,, I ,� I 74 1I�- t � -.I 1 ,1
v II I,, ;, 1,
�
I�, ', I "'," -t I I"--'O. f-`, �,', ", -- I-t- . 1-�.11� -;,--iI 1, -t .1, �'-. 14 ,. �4.l IL, "- - ".��.,-i"4�I6. 1"t1:- -tt�� "- ,".1 't . , . 1,
-. - , r�..1--4 ,
,,, ,.. I. II-, *" "" J, -I-i" k"I--I-"I,
-
�, -� . , 7 - , - I I - - -1 I � "' �,., ; . , - I I . I I � . " -., . � "'. . I I ,� . .,
t, , - , - - , fir
. . , . - . . . . 0
,. '. . , � ,,z .., - - , - - l I - , ;i. -
- - - I - I �
, - - ,11,t 6- � ,I- 11 - � 11 I . I . - , .
lk . . . � 1pl%- - * �1- , 1, I I . I , � - .,. ,- . . - .- I, .
- - I . -�-, 'i - I
I I -,!. " I �-, ,I1—��-�.
2
,
I-",
-1e.-Xl1 -t l %�rfI, I 4"..,
-,.,.-,",.
.I
..
,
� " " L ,1 kI, ,; ,
I'- 1, , . -, . t h, I t I I I i-, ,r ,r ,
4. ♦'iID-� I 1
- -:- - -1,- ,"- 1 � t .
-- I -L . t. �� -1- '"°,,,,,_.* ,-%,,t;r �", - Y. "t!II , l
.,
11
,-�-."'-7, - Z-�I-k - "
.4, 1�"-,Y "I -I'-
,.�.,,-'-.4,'t 10
.�,"%'tT.s,-1S-1
I" ; "-,t.-c,p-V,-
Ft,,, t,Z
,�.
1--,t 1
I1 �,
'
71
�...%,
"
1.
I.,11
t"1P,.,t,, M. "I'4 f -�ttI 1�-,1�j�4,� , /-w-�".vT ,-v t", r-� ,t.1$yr, 4r 1,,"".0 .Ir Ctjl��, �1 " -; fl ,
I ;-,y eI, " I, , -,1t;:) �'I -.4-1�jiC-3,,, 11I "
�
-I
,I
1
I.
,
1
.�
,
I �,.4+, 1, - , 5"1"" j ,-,�Y, t,j.;1:),t",,1,%IS ,I,r,�, �"."i > a �I , 'I
r -1,"1,, I-11"- ",�It �j"� e II ,1fY "'," ,t
II I1", k'Vt, E� I �-;k t�?�,�I-t1I %�1i,
e " ..f-, `,l."-,,,-I ,I" I,-, i�,,, ,","
i .IlV-74-"-I)N; ,j,,, 11C-1,.,�tC, �1- -4_� 1-k t,_--dI
I-{`,;7 ) , I* eA-,I4_";�,, �II, I 1", "tI N I"w.��,,r,.-I,41V , %.I ",t n,"I
I 1I;, t ( tI , 1 �-e,I J ,
r� iPI ?` - -"' ",4,-1," I It . ViI I
k-: i'�,-"`rt,�y *,) I"t,bt 1,,- t- -.I ,--, I -,",--,
l-�
,.;
-1.-
-.'
�I..
V• ,tr t-,,�"'.--It.�-M1, " , ,, ",�. 1.I
, 1
,.,',';j-'--, , I° �,"l11 ,t ;i�,-,114-�-,jr I"{i•
"ti�
} - 1_- I I -1 ,,,24 ,",,,-1"1, ,
/ I 'Si A11.IOe1',V. , z 4 " , ,-?r k , �,,Z
I �""�, aw �1.*-, yi,,,4�1 ,1i 1"I " r'P'
3,; ,,,-" is S",-,,.yL �.� t.,,'1l,,�.".. "-
-%x , ,,3,-V,,, ,Wp,,k�-i�Ps- &,,,;t1h ,V,P ,, " I
, ) � ,, 4 I, WII, t-" I1 F �, 1",I -�% Ni �"Ybpi -1'�!,',� Itt , I . .
-
,
1.
,IN" ,-�,VJ-�. >,;",,I�k�,I_.,.", -1�, 11,I^11" pf�t-A ji, " lj�*It"t"�q, ..
,i ."-"', ;i 19 ,N �tyo"4tvIt) ',,t",�",t,i,I f4-�: ,", "
Vg&�,VPCII 1�,1iF"�T" � :1 � - At
I. ,,,-, �41, 4 , �C1
,"1r} I,-,4I "1.i. I � ,-4h,,. , , II"y- �
N ,- I"- "rI - ,, I . ��,-I •", -I,i I ,-" �
l, ,",�-�-,V, " ��,t ", ,-�,, ,- , .
A 1 t � -. 1 -, it
i"'--f i1-,,�ItW �, I , I " ,:sl f_ fAttlN',-O- , ,, 4 QW, �l 4 i , 'N�, ,'�- 4,k-N-4 11" ,"'I' -
t.
-
,I
�,",,,"-I "q-, I -"v.,l�,. - ,1. Z� ,.,�..,c �I ,4 -, `1, �� - , I � ,4 ;I, 1 . ...
,A" , - �1)- I �
- `. i -.L" .lLI.t' 1',, . I�. -I, Il-l
V J.
," -
II
I
� Q,,
r F,t"- � , .-e
-
I
.
.'
-.
.,I ` " ""
t ,,,,,, I • - , - , - t'- - .I r, V ,� 4.I
I
,
ki.. i, .Z zi"t, - Y -_ � " I ' , . ,
FINAL DRAINAGE AND EROSION CONTROL STUDY
TOWNHOMES
AT
TIMBER CREEK, P.U.D.
Prepared for:
KEM COMPANY, LLC
3000 South College Avenue, Suite 103
PO Box 1845
Fort Collins, CO 80522
Prepared by:
North Star Design
1200 Carousel Drive, Suite 201
Windsor, Colorado 80550
(970)686-6939
November 23, 1999
Job Number I I 1 -0 1
North Star
�ftw�. design —
November 23, 1999
Basil Hamdan
City of Fort Collins Stormwater
700 Wood Street
Fort Collins, CO 80522-0580
a
RE: Final Drainage and Erosion Control Study for the Townhomes at Timber Creek
Dear Basil,
I am pleased to submit for your review and approval, this Final Drainage and Erosion Control
Study for the Townhomes at Timber Creek. This report for the final drainage design of the
Townhomes at Timber Creek was prepared in accordance with the criteria in the City of Fort
Collins Storm Drainage Manual.
I appreciate your time and consideration in reviewing this submittal. Please call if you have any
nn Psti nn -
ii
' 1200 Carousel Drive, Suite 201 Windsor, Colorado 80550
9 7 0 - 6 8 6 - 6 9 3 9
Phone & Fax
TABLE OF CONTENTS
ABLEOF CONTENTS ............................................................................................................... iii
GENERAL LOCATION AND DESCRIPTION
1.1 Location..............................................................................................................:....1
1.2 -Description of Property............................................................................................1
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description..........................................................................................1
2.2 Sub -Basin Description.............................................................................................I
3. DRAINAGE DESIGN CRITERIA
3.1 Regulations..............................................................................................................2
3.2 Development Criteria Reference and Constraints...................................................2
3.3 Hydrologic Criteria..................................................................................................2
3.4 Hydraulic Criteria....................................................................................................3
4. DRAINAGE FACILITY DESIGN
4.1 General Concept......................................................................................................3
4.2 Hydrologic Analysis of the Proposed Drainage. Conditions....................................3
4.3 Specific Flow Routing.............................................................................................4
4.4 Drainage Summary ..................................................................................................5
4.5 Water Quality...........................................................................................................6
5. EROSION CONTROL........................................................................................................6
5.1 General Concept.....................................................................................................6
5.2 Specific Details........................................................................................................6
6. CONCLUSIONS
6.1 Compliance with Standards....................................................................................7
6.2 Drainage Concept....................................................................................................7
7. REFERENCES....................................................................................................................8
APPENDICES
' A Vicinity Map
B Hydrologic Computations
C Erosion Control Calculations
' D Excerpts from Previous Reports
E Figures and Tables
iii
' 1. GENERAL LOCATION AND DESCRIPTION
' 1.1 Location
The Townhomes at Timber Creek is a proposed 5.1 acre multi -family residential
development. This project is located in the West half of Section 5, Township 6 North,
Range 68 West of the Sixth Principal Meridian, in the City of Fort Collins, Larimer
' County, Colorado.
' The project is a portion of the Timber Creek P.U.D and is located in the northeast corner
of the intersection of Timberline Road and Timber Creek Drive. The project is bounded
' on the south and east by the single-family portion of Timber Creek P.U.D., on the north
by property owned by Poudre Valley Hospital currently under development and on the
west by Timberline Road.
' 1.2 Description of Property
The entire project consists of approximately 5 acres of land. The land is currently
undeveloped and slopes to the south at, approximately No. A drainage swale has been
iconstructed along the north property line to divert off site flows to the east.
' The project will consist of 13 buildings containing 4 or 6 units each and detached
garages. A private road will provide access to the site and will have some off street
1 parking.
2. DRAINAGE BASINS AND SUB -BASINS
2.1 Major Basin Description
The proposed development lies within the McClellands Drainage Basin. Runoff from the
project area currently flows overland to Timber Creek Drive and is routed to the existing
' Detention Pond 373 in the southeast corner of Stetson Creek P.U.D.
' 2.2 Sub -basin Description
This site encompasses basins 202 and 203 and portions of basins 204 and 205 as
delineated in the Final Drainage and Erosion Control Study for Timber Creek P.U.D. by
t
1 "
' RBD Engineering (see Appendix). The site has been graded to conform as nearly as
possible to the basin delineation and runoff calculations previously completed with minor
' revisions due to existing fences impeding proposed flow paths along the south property
line. A table comparing the values estimated by the RBD report and the values proposed
with this development for area, C values, and runoff for the minor and major storms is
included in Appendix B. These basins are shown on the Final Drainage and Erosion
Control Plan in the back pocket of this report and a more detailed description of each
basin is located in section 4.3 of this report.
' 3. DRAINAGE DESIGN CRITERIA
' 3.1 Regulations
This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage
' Design Criteria Manual" specifications. Where applicable, the criteria established in the
"Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver
' Regional Council of Governments, has been used..
3.2 Development Criteria Reference and Constraints
' The runoff from this site has been routed to closely conform to previous calculations
' completed with the Final Drainage and Erosion Control Study for Timber Creek P. U.D.
First Filing by RBD Engineering Consultants dated July 1, 1994. Detention for this site
is provided in the Detention Pond 373 as noted in the above mentioned report. A
majority of the runoff from this site will be collected in an inlet in Timber Creek Drive
and conveyed to the detention pond via storm pipe.
The streets and associated drainage systems surrounding the site are existing. The
' existing storm system was designed by RBD. Engineering and was sized to convey the
additional runoff resulting from the development of this site.
3.3 Hydrologic Criteria
' Runoff computations were prepared for the 2-year minor and 100-year major storm
frequency utilizing the rational method.
' All hydrologic calculations associated with the basins are included in Appendix B of this
2
' report. Time of concentration calculations for all sub -basins and a summary of the design
flows at all Design Points associated with this.site are included in Appendix B.
' Detention for this site is provided off site, therefore no discharge and storage calculations
were performed.
3.4 Hydraulic Criteria
' All hydraulic calculations within this report have been prepared in accordance with the
City of Fort Collins Drainage Criteria and are also included in the Appendix of this
report.
1 4. DRAINAGE FACILITY DESIGN
4.1 General Concept
The site was graded to maintain (as closely as possible) the drainage patterns dictated in
the Final Drainage Report for Timber Creek P.U.D. The majority of the runoff from the
site will now to the south and into an inlet in Timber Creek Drive. A portion of the site
' will drain east to Pole Pine Lane and be conveyed via gutter flow to a sidewalk culvert in
Smallwood Drive. The runoff is then conveyed in a grass swale to the detention pond.
4.2 Hydrologic Analysis of the Proposed Drainage Conditions
The Rational Method was used to determine both the 2-year and 100-year peak runoff
values for each subbasin. The Rational Method utilizes the equation:
Q=CIA (1)
Where Q is the flow in cubic feet per second (cfs), A is the total area of the basin in
acres, C is the runoff coefficient, and I is the rainfall intensity in inches per hour. "C"
values were determined using Table 3-3 of the "City of Fort Collins Storm Drainage
Criteria Manual" and I was determined from Figure 3-1. Although new rainfall criteria
was accepted by the City of Fort Collins on March 26, 1999, this project is utilizing the
rainfall intensity duration curve dated November, 1975. The original submittal date for
this project was prior to the implementation date of the new rainfall criteria and is
therefore, allowed to utilize the previous rainfall curves.
3
4.3 Specific Flow Routing
A summary of the drainage patterns within each basin is provided in the following
paragraphs.
Subbasin 201 contains the cast half of Timberline Road along the site fi-ontage and a
portion of the north half of Timber Creek Drive along the frontage. Runoff from
Subbasin 201 is conveyed via gutter flow to the main envy ol' the site and into Subbasin
204.
The runoff from this Basin was estimated with the RBD report to be 2.04 cfs in the 2 year
event and 7.87 cfs in the 100 year event. The actual runoff from Basin 201 with this
development will be reduced to 1.97 cfs in the 2 year storm and 7.35 cfs in the 100 year
storm.
Subbasin 202 contains the western portion of the site. Runoff from Subbasin .202 is
conveyed via overland flow and swales to the interior street. The flow is then routed
southwest in the street to the main entry where the runoff combines with runoff from
Subbasin 201 and enters Subbasin 204.
The runoff from this Basin was estimated with the RBD report to be 4.46 cfs in the 2 year
event and 18.34 cfs in the 100 year event. The actual runoff from Basin 201 %vith this
development will be increased slightly to 5.00 cfs in the.2 year storm and 19.56 cfs in the
100 year storm. This increase is due to a higher C value than was. estimated.
Subbasin 203 contains the eastern portion of the site. Runoff from Subbasin 203 is
conveyed via overland flow and swales to the interior street. The runoff is then routed
east in the street to a concrete channel that conveys the flow to Pine Pole Lane.
The runoff from this Basin was estimated with the RBD report to be 2.26 cfs in the 2 year.
event and 9.20 cfs in the 100 year event. The actual runoff from Basin 201 with this
development will be higher than was estimated and will be 2.54 cfs in the 2 year stone
and 9.92 cfs in the 100 year storm. This increase is due to an increase in area for this
Basin and a slight increase in the C value.
Subbasin 204A contains the southern portion of the site. Runoff from Subbasin 204A is
conveyed via a swale with a concrete pan to the Timber Creek Drive. The runoff is then
4
combined with runol'f from Subbasin 204 and routed to the existing inlet at design point
4.
Subbasin 204A' deviates from the original overall drainage report Ior Timber Creek
Subdivision. The area contained in 204A should be contained in Subbasins 204 and 205
but. due to existing fences impeding proposed flow paths, a portion of each Subbasin has
been rerouted. The total runoff from Subbasins 204A. 204 (as revised) and 205 (as
revised) does not exceed the total allowable runoff in the overall drainage report for 204
(original) and 205 (original). The total runoff estimated for Basins 204 and 205 was 5.01
cfs in the 2 year event and 19.54 cfs in the 100 year event. The total runoff I'or Basins
204A. 204 and 205 proposed with this development is 4.72 in the 2 year storm and 17.73
cfs in the 100 year storm.
Subbasin 204 contains 3 existing single-family lots. Runoff from Subbasin 204 is
conveyed to Timber -Creek Drive via existing side lot swales alone Lots I, 2 and 3. The
runoff then combines with flow fi•om Subbasins 201, 202 and 204A and into the existing
inlet at design point 4.
Subbasin 205 contains 12 existing single-family lots. Runoff from Subbasin 205 is
conveyed to Timber Creek Drive via existing side lot swales. The runoff then flows into
the existing inlet at design point 5.
4.4 Drainage Summary
There were not any drainage problems encountered on this site. Proposed drainage
patterns were delineated in order to minimize impact on existing housin(l. Basins were
modified slightly from the predicted basin layout in the RBD report but total runoff from
the site is within restrictions outlined in that report.
The storm conveyance system is primarily a surface system and has been designed for
minimum maintenance. The City of Fort Collins will be responsible for maintenance of
storm drainage facilities located within the right-of-way. The drainage facilities located
on this site will be maintained by the The Townhomes at Timber Creek Master
Association..
F
4.5 Water Quality
' This site is a portion of the overall Timber Creek Subdivision and shares detention
facilities with the overall subdivision. Water quality measures were not implemented in
' the remainder of the Timber Creek Subdivision and therefore are not being proposed with
this site. The effects of any water quality measures implemented on this site would not
be evident after runoff from this site is combined with the runoff from the remainder of
' the subdivision at the detention area.
5. EROSION CONTROL
5.1 General Concept
This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort
Collins Zone Maps. The potential exists for silt movement from the site and into the
existing storm system during construction.. Potential also exists for tracking of mud onto
existing streets which could then wash into existing storm systems.
' Per the City of Fort Collins Erosion Control Reference Manual for Construction Sites and
related calculations in Appendix D, the erosion control performance standard for the
subject site is 76.7%. The erosion control plan gives a performance standard of 77.01/o.
' The erosion control escrow amount is S4936.
5.2 Specific Details
To limit the amount of silt leaving the site several erosion control measures shall be
' implemented during construction. The west boundary shall have silt fence installed and
gravel filters shall be installed at the metal sidewalk culverts to reduce sediment leaving
' the site. All area to be sodded or seeded shall have a straw mulch applied and maintained
until a grass cover can be established. A vehicle tracking pad shall be installed- at the
entry onto Timber Creek Drive to control he mud being tracked onto the existing
pavement. Any mud tracked onto the public streets shall be cleaned on a daily basis.
During overlot grading, disturbed areas are to be kept in a roughened condition and
' watered to reduce wind erosion.
6
6. CONCLUSIONS
6.1 Compliance with Standards
All computations that have been completed within this report are in compliance with the
Storm Drainage Design Criteria Manual and the City of Fort Collins Erosion Control
Reference Manual for Construction Sites.
6.2 Drainage Concept
The proposed drainage concepts presented in this report and on the construction plans
adequately provide for the transmission of developed on -site runoff to Timber Creek
Drive or Pine Pole Lane where the runoff will be conveyed in existing facilities to the
existing downstream detention facility. The onsite street capacities and off site storm
drain system will provide for the 2- year and the 100- year developed flows to reach the
existing detention facility. The existing receiving detention facility has been sized to
accommodate developed runoff from this site.
If, at the time of construction, groundwater is encountered, a Colorado Department of
Health Construction Dewatering Permit would be required.
7
7. REFERENCES
I. City of Fort Collins, "Storm Drainage Criteria Manual", (SDCM), dated March,
1986.
2. Urban Drainage and Flood Control District, "Urban Storm Drainage Criteria
Manual", Volumes 1 and 2, dated March, 1969, and Volume 3 dated September,
1992,
3. Guo, James C.Y., PhD, P.E. "Street Hydraulics and Inlets Sizing using the
Computer Model UDINLET". University of Colorado at Denver, January 1995.
4. StormCAD v.1.5, Storm Sewer Design &Analysis Software by Haestad Method,
1997.
8
APPENDIX A
VICINITY MAP
HARMONY ROAD
Q
O
Qz
W
N,
O
I�
H0R5ETOO7H ROAD
PROJECT
S TE
CITY LIMITS
COUNTY ROAD 36
FOSSIL CREEK RESERVOI
VICINITY MAP
' APPROXIMATE SCALE: 1" = 2000'
APPENDIX B
HYDROLOGIC COMPUTATIONS
I
I
III
11
ME&Z
3 POLE-44NF,
14
r
3 7
-� � 1 I ®
I( 5
4
---------------
IWARE-Amil-
TIMBER CREEK DRIVE
01
'
North Star Design
1200 Carousel Drive, Suite 201, Windsor, CO 80550
'
RUNOFF COEFFICIENTS & % IMPERVIOUS
LOCATION:
The Townhomes at Timber Creek
PROJECT NO:
111-01
COMPUTATIONS BY: ,
ppk
DATE:
11/23/99
' Recommended Runoff Coefficients from Table 3-3 of City of Fort Collins Design Criteria
Recommended % Impervious from Urban Storm Drainage Criteria Manual
1
1
1
1
1
1
Streets, parking lots (asphalt)
Sidewalks (concrete)
Roofs
Lawns (flat <2%, sandy soil)
Runoff
%
coefficient
Impervious
C
0.95
100
0.95
96
0.95
90
0.25 1
0
SUBBASIN
DESIGNATION
TOTAL
AREA
(ac.)
TOTAL
AREA
(sq.ft)
ROOF
AREA
(sq.ft)
PAVED
AREA
(sq.ft)
SIDEWALK
AREA
(sq.ft)
LANDSCAPE
AREA
(sq.ft)
RUNOFF
COEFF.
(C)
%
Impervious
201
1.08
46,880
3,294
20,323
3,056
20,207
0.65
56
202
2.89
125,770
34,488
38,251
9,047
1 43,984
0.71
1 62
202C-C
0.36
15,489
1 5,832
4,618
867
4,172
0.76
69
2020-D
0.92
39,988
9,811
8,892
1,784
19,501
0.61
49
202E-E
1.95
84,774
20,223
25,806
5,512
33,233
0.68
58
203
1.51
65,819
16,205
19,066
4,398
26.150
0.67
58
203A-A
0.53
23,270
7,204
7,155
1,461
7,450
0.73
65
20313-B
0.32
13,914
3,635
5,936
615
3,728 -
0.76
70
204A
0.66
28,625
9.252
0
4,292
15,081.
0.58
43
204
0.90
39.254
3,600
9,871
1
25,783
0.49
33
205
2.81
122,349
11,400
25,966
84,983
0.46
212
3.00
130,705
13,800
30,702
86,198
0.49
NOTES:
1. Basin 201 area increased slightly from RBD report but C value is less than predicted in RBD report
2. Basin 202 was reduced by 0.09 acres and area was added to Basin 204. C value is slightly higher than RBD report predicted.
3. Basin 205 area remains same as RBD report. C value is less than predicted
4. Basin 212 was reduced by 0.12 acres and area was added to Basin 203. Area impervious remains the same as RBD report
5. For Basin comparisons with RBD report, see table at the end of Appendix B.
Equations
- Calculated C coefficients & % Impervious are area weighted
C=£(Ci Ai) /At
Ci = runoff coefficient for specific area, Ai
Ai = areas of surface with runoff coefficient of Ci
n = number of different surfaces to consider
At = total area over which C is applicable; the sum of all Ai's
' Flow.xls Cval
i'4
.11
z
O
N
N
z
� W
w z
p
�U
LL
=p
F Q
N WW
C_
F
N
Y
is
W
R'
�C
C)
O
Cl
C)
Q
O
Q
O
m
N
Q
LL
cC
N
m
Q
Q
N
a0
O
m
N
O
f
m
N^
N
N
N^^
t7
N
M
om 5 m
E
v
It
m
U
..
p
W
V
J
p
<O
N
M
O
Q
N
m
N
Q
N
lmC
U 7
IC
q
C)
m
C)
Q
N
Q
CO
N
N
Q
u r�
noc
n
n
oQ
vin
c
00
U �
D
N
n
O
N
0
m
UN
O
tOC
O
N
N
O
N
O
1.7
LL
J
W
Q
Q
N
O
N
O
Q
Q
Q
Q
N
tC
IC
W
2
N
^
-
N
N
-
Jq
U
^
LL'
'c
C
o
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
O
O
o
O
C
0
0
0
0
O
O
C)
O
O
O
C
O
N
N
0
0
0
0
N
iC
N
N
N
N
N
tC
O
N
O
O
N^
N^
0
0
0
0
0
N
O
e m
O
C
N
W
i
o
m
o
N
m
o
M
o
a
o
w
m
l
Q
H
J
L
O
tC
O
Q
S
N
'•
N
m
N
0
^
N1
O
N
O
m
O
N
N
N
m
m
O
N
C Z n
>
v
Q
J
^
N
W
C)
n^
CI
CI
O
n
N
N^^
N^
O
0
0
0
0
0
0
N
N
N
O
O
lV
N N
N
N
IC n
N
N
N N
N
N
N
p
o
o
v�
m
m
o
in
rn
o
0
Q
N^
n
n
N
�-•
N
N
CO
N
m
C � Q
>
p
N
n
m
w
nm
ro
eo
m(o
o,
w
U m
o
o
n
c
f0
o
Lp
0
0
0
n
0
n
0
N
0
IT
0
Q
0
Q
0
�
z�
_ F
O
m
m
m
rn
in
N
M
m
T
w
o
GN
Z
U
O
w
Q
m
N
N
N
N
ppyy
N
m
N
N
N
N
N
N
N
z
ca
z F
m H
N O
^
N
m
Q
Q
N
N
wa
N O
�
c .
r_
C
Cto
L
C
Ol
.y
d
N
C
O
U
O
U
O
M
of
7
_m
LL
O
N
U
C
°a
N
t
C)
N
N
t_
Z
3
U
LL
O
U Q
N
7
U O
Q
C N
y
In
.E
m
O
N
C
N j
m
-e c
e
E
E
�
w
C In
N
O
J
�' C
>
`o E
U
E
U
E
Zp
E
a
+
n
°o
It
II
s
(�
U
II
II
ca
W
a
w
U
0
O
O
r
z
O
N
N z
iZ
� W
w z
G
=O
F o
N WW
L
N
Y
f
W
C
r
0
lh
l7
N
fG
OD
to
N
In
r
Yi
N
n
N
fh
M
tO
q
N
N
V
n
O
m
r
lO
q
N
C fh
=
m
E
m
ii
WZ
_J
tD
N
N
M
O
lNO
n
th
ONl
O
fp
S m
_
Z N
U �
F
u �
II � •-•
�O
OC
Cl
N
IA
n
l")
O
Ih
(V
t7
Nl
U #
OWeemj
Om
o
In
IT
IT
In
In
Ic
z
y
N
N
N
NS
VC0
'
0
0
0
0
0
0
0
0
0
0
0
0
0
0
O
K
w
a
c
0
0
0
0
0
0
o
c
o
0
0
o
c
o
N
N
N
N-
N
N
N'R
y
0
0
O
O
O
T
O
O
W
o
In
om
0mmoov�fc
M0
p0
O
N
w
w
C Z A
m .
T
q
J
F �
m
Q
tO
N
O
C
NMOM
N
V-
0-
m
m
N
_ E
0
0
0
0
0
0
0
0
0
0
0
0
m
60
N
N
fV
O
Q
N
N
N
N
fV
N
N
�
N
O
N
N
N
N
L
n
n
N
N
M
w
N
�s!a
J
am
amn
a
a.rn
m
6ic�m
�
00co
0
0000000
�
U
ei�nlo
�
mnn
�ia
ee
��
0
0
0
0
0
0
0
=i
_ H
o
Ow
m
0
C�
Y1
1N
m
IR
OOi
Co
yvN
�NOO
�OGOONn'J
GN
Z
1Lu
1
Q
O
O
U
W
Q
m
y
g
o
N
N
N
N
ON
N
N
N
m
D
N
N
N
N
N
z
zr
w a
N O
Q
o_
U
LL
LL
O
Z
Y
Q
W
a
c
WN
C v
J
Q
Z
O
H
a
s
N
h
U
N
Q
m
N
N
N
J
U
m
U
U
N
c
O
a
Y
Cd'
<°
a
E
a
E
a
E
c
y
H
v
H
F
d
W
d
o
0
0
0
0
It
y
c
c
I
c
c
c
C
n
Q m
V
N
m
N
O
m
O
N
Oni.
Oco
(OO
w
N
r
O
Q
O
N
O
M
N
G
O
O
fV
M
F
O
F
v 4)
O u
W
O
c
>
E rn c
a
U
V m
n
Ol
ono
0
D7
t0
rn
O�
N
NNOOM
A
0)
A
O
Q U
C)
O
th
N
O
fV
C1
R
C
nW
7
A
M
N
COO.
0
N
N
N
fV
(h
N
N
N
M
M
fV
N
N
N
E
A
O
N
n
A
O
N
N
n
N
C7
N
U
�nnmm�nnu°Divvv
U
o
0
0
0
0
0
0
0
0
0
0
0
0)
nr�o
QCD
o
wctOrn
O
min
v�i
rncoo
'-
N
o
O
O
OO
OO
6
N
N
LL
LL
O
Z
>
m
>
O
O
W
O
¢
m
0
O
N
N
N
m
a
F
F
N
N
N
C
N
N
N
N
N
rn
Ncoo
N
N
N
w
s
c..
N
N
9
U
O
v
d
LL
LL
O
Z
Y
WaLU
Q
}
W
J
Q
O
Y
H
qpi
`
U
E
F-
H
L
G
3 �
F o
N
u
U
�+
O
m
h
Z
O
P: U
Irt a
OCnt0¢
a a U A
d
�¢ao
c
U
O
W
W
Q
m
O
C
d
N
O
O
O
t
y
0
0
x
N
x
N
J
Y3
d
N
N
N
N
N
d
d
cC�
cC�
E
E
c
1
d
~_
O
D
C
U
.0
U
N
.0
C
.�
W
C
1N
C
Q
Q
Q=
p
Q
Q
O
c
O
c
O
c
p
O
m
r`�i
m
Q
O
O N
M
<0
N
O
N
(0
M
ON1
tM'),
A
W
00
N
O
f0
1�
O
M
t0
<
O
7
N
07
ri
•-
O
�
H
U
W
O
Y
E rn `E
z
o 'o
a
U
O N
M
O
N
�
Ci
n
00
pp
f0
N
0
f�
O)
m
tGCl
<
Oi
O
fV
M
f7
O
- t
M
7
O
w
M
W
N
CO
O
N
O
M
O)
M
O)
e0
01
T
0
M
5
w
m
mw
ai
n
wco
U C
O
V
GD
O
O
M
Cl
N
U
66000
rn
rn
n
ro
u
U
0
0
0
0
o 0
c
o
0
0
00
0
Q U
N
co
w
M�
m
N�
M�
N
O
O
�
N
00
0
0
0
O
fV
Ci
LL
O
7
m
N
U
D
W
M
Q
[f1
Q
V
N
N
W
K
O
0 a
N
M
V
a
N
N
2
U
LL
E
0
w
C U
rn.? .2;' @
L c
W
y U C y
Co
O
Y C_
N r
Iv C C
0. M
II II ` II
C7 U ° Q
N
3
O
LL
00
CC) W
w z
0
LL
� - -- - - �- - r,�i,
�... 1
���
�i =�' . �i C� �
.,
►. __
III- _ �`
I � _
�� 1 `� � I,' ,.
_. __
�,,. � ,.
E �. , -� •�
�♦ ��
.. \ _
_ ._
_�
. .
� -' _ �
,, � ,� � � ,
/ �.
/�/ �, � � R
� - � � ,,��
_�
,r
--
- -
A
Section A -A
' Cross Section for Irregular Channel
' Project Description
Project File f:\programs\haestad\fmw\tcreek.fm2
Worksheet parking lot flows A -A
Flow Element Irregular Channel
Method Manning's Formula
Solve For Water Elevation
' Section Data
' Wtd. Mannings Coefficient 0.014
Channel Slope 0.50 %
Water Surface Elevation 43.64 ft
' Discharge 4.33 cfs
44.
' 43.
' 43.
' 43.
c
0
m 43.E
lL
' 43.:
43.,
' 43.:
t 43.:
0.0
.1
11/22iss
�4:56:04 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.6 50.0
Station (ft)
-FlowMaster v5.15
Page 1 of 1
Basin 203 Section A -A
' Worksheet for Irregular Channel
Project Description
'
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows A -A
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
'
Input Data
'
Channel Slope 0.50 %
Elevation range: 43.27 ft to 44.02 ft.
Station (ft) Elevation (ft)
Start Station
0.00
43.79
0.00
'
3.00
43.43
5.00
4.00
43.27
5.00
43.43
'
49.00
44.02
Discharge
4.33 cfs
'
Results
Wtd. Mannings Coefficient
0.014
'
Water Surface Elevation
43.64
'ft
Flow Area
2.32
ft'
Wetted Perimeter
19.08
ft
Top Width
19.04
ft
'
Height
0.37
ft
Critical Depth
43.63
ft
Critical Slope
0.005640 ft/ft
'
Velocity
1.86
ft/s
Velocity Head
0.05 .
ft
Specific Energy
43.69
ft
'
Froude Number
0.94
Flow is subcritical.
1
End Station
5.00
49.00
Roughness
0.013
0.016
11/22/99 FlowMaster v5.15
t04:56:21 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
Section B-B
' Cross Section for Irregular Channel
Project Description
'
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows B-B
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Section Data
Wtd. Mannings Coefficient
0.013
Channel Slope
0.50 %
Water Surface Elevation
43.66 ft
Discharge
2.72 cfs
44.1
44.0
43.5
43.6
c
0
� 43.7
W
' 43.6
43.5
' 43.4
' 43.3
0.0
11/22/99
05:02:09 PM
5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0
Station (ft)
FlowMaster v5.15
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
'
Basin 203 Section B-B
'
Worksheet for Irregular Channel
Project Description
'
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows B-B
Flow Element
Irregular Channel
'
Method
Manning's Formula
Solve For
Water Elevation
'
Input Data
Channel Slope
0.50 %
'
Elevation range: 43.33
ft to 44.11 ft.
Station (ft)
Elevation (ft) Start Station End Station
0.00
43.74 0.00 5.00
'
3.00
43.50 5.00 49.06
4.00
43.33
5.00
43.50
'
49.00
44.11
Discharge
2.72 cfs
Results
Wtd. Mannings Coefficient
0.013
Water Surface Elevation
43.66
ft
Flow Area
1.59
ft'
Wetted Perimeter
15.68
ft
Top Width
15.65
ft
Height
0.33
ft
Depth
43.66
ft
_Critical
Critical Slope
0.005595 fUft
Velocity
1.71
ft/s
Velocity Head
0.05
ft
Specific Energy
43.71
ft
Froude Number .
0.94
Flow is subcritical.
Roughness
0.013
0.016
11/22/99 FlowMaster v5.15
' 05:02:22 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 _ Page 1 of 1
' Section C-C
' Cross Section for Irregular Channel
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows C-C
' Flow Element
Method
Irregular Channel
Manning's Formula
Solve For
Water Elevation
Section Data
.'
Wtd. Mannings Coefficient 0.013
Channel Slope
0.75 %
Water Surface Elevation 43.02 ft
Discharge
3.02 cfs
' 43.15
43.1
43
4
42
r-
C
0 4,
' to
0
W 42
11 /23/99
' 08:06:55 AM
4:
42.
4:
42.
.0
3.0
.95
2.9
85
?.8
75
>7
65
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0
Station (ft)
FlowMaster v5.15
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
'
Section C-C in Basin 202
'
Worksheet for Irregular Channel
Project Description
'
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows C-C
Flow Element
Irregular Channel
'
Method
Manning's Formula
Solve For
Water Elevation
Input Data
Channel Slope
0.75 %
'
Elevation range: 42.69
ft to 43.12 ft.
Station (ft)
Elevation (ft) Start Station End Station
0.00
43.05 0.00 5.00
'
3.00
42.86 5.00 18.00
4.00
42.69
5.00
42.86
'
18.00
43.12
Discharge
3.02 cfs
1
Results
Wtd. Mannings Coefficient 0.013
Water Surface Elevation 43.02 ft
Flow Area
1.38 ft2
Wetted Perimeter
12.79 ft
Top Width
12.75 ft
'
Height
0.33 ft
Critical Depth
43.04 ft
Critical Slope
0.005430 ft/ft
'
Velocity
2.19 fus
Velocity Head
0.07. ft
Specific Energy
43.10 ft
'
Froude Number
1.18
Flow is supercritical.
Roughness
0.013
0.016
. 11 /23/99
08:07:32 AM Hassled Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMaster v5.15
Page 1 of 1
Section D-D
Cross Section for Irregular Channel
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows D-D
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Section Data
Wtd. Mannings Coefficient
0.014
Channel Slope
1.00 %
Water Surface Elevation
43.59 ft
Discharge
6.20 cfs
44.
44.
43.
43
W 43.
43.
43.
43.
43._
0.0
11/23/99
' 08:07:45 AM
5.0 10.0 15.0 20.0 25.0. 30.0 35.0 40.0 45.0 50.0
Station (ft)
FlowMaster v5.15
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
Section D-D in Basin 202
Worksheet for Irregular Channel
Project Description
Project File f:\programs\haestad\fmw\tcreek.fm2
Worksheet parking lot flows D-D
' Flow Element Irregular Channel
Method Manning's Formula _
Solve For Water Elevation
Input Data
Channel Slope
_ 1.00 %
'
Elevation range: 43.20 ft to 44.17 ft.
Station (ft)
Elevation (ft)
0.00
43.59
'
3.00
43.37
4.00
43.20
5.00
43.37
'
49.00
44.17
Discharge
6.20 cfs
Start Station End Station
0.00 5.00
5.00 49.00
'
Results
Wtd. Mannings Coefficient
0.014
Water Surface Elevation
43.59
ft
'
Flow Area 1
2.23
ftZ
Wetted Perimeter
16.97
ft
Top Width
16.93
ft
'
Height
0.39
ft
Critical Depth
43.62
ft
Critical Slope
0.005305 ft/ft
'
Velocity
2.78
ft/s
Velocity Head
0.12
ft
Specific Energy
43.71
ft
'
Froude Number
1.35
Flow is supercritical.
Roughness
0.013
0.016
11 /23/99
' 08:08:09 AM
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
F_IowMaster v5.15
Page 1 of 1
' Section C-C and E-E
Cross Section for Irregular Channel
'
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows C-C and E-E
'
Flow Element
Method
Irregular Channel
Manning's Formula
Solve For
Water Elevation
Section Data
Wtd. Mannings Coefficient
0.014
'
Channel Slope
0.53 %
Water Surface Elevation
43.04 ft
Discharge
17.38 cfs
1
1
11 /23199
08:08:21 AM
43.1
43.05
43.0
42.95
42.9
42.85
C
0 42.8
CO
tv
lL 42.75
42.7
42.65
42.6
42.55
42.5
).0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0
Station (ft)
FlowMaster v5.15
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
'
Section E-E in Basin 202
Worksheet
for Irregular Channel
'
Project Description
'
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
parking lot flows C-C and E-E
Flow Element
Method
Irregular Channel
Manning's Formula
Solve For
Water Elevation
'
Input Data
Channel Slope
0.53 %
'
Elevation range: 42.55
ft to 43.06 ft.
Station (ft)
Elevation (ft)
Start Station End Station
1.00
43.06
1.00 7.00
'
5.00
42.75
7.00 33.00
6.00
42.58
33.00 38.00
7.00
42.75
'
20.00
43.01
33.00
42.72
34.00
42.55
35.00
42.72
38.00
43.05
Discharge
17.38 cfs
Results
Wtd. Mannings Coefficient 0.014
'
Water Surface Elevation 43.04
ft
Flow Area
6.91
ft2
Wetted Perimeter
36.77
ft
'
Top Width
36.68
ft
Height
0.49
ft
Critical Depth
43.04
ft
'
Critical Slope
0.005212 ft/ft
Velocity
2.49
fus
Velocity Head
0.10
ft
'
Specific Energy
43.14
ft
Froude Number
1.01
Flow is supercritical
Roughness
0.013
0.016
0.013
11 /23/99
08:08:48 AM
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMaster v5.15
Page 1 of 1
Section F-F
Cross Section for Irregular Channel
' Project Description
Project File
Worksheet
1 Flow Element
Method
Solve For
f:\programs\haestad\fniw\tcreek.fm2
Section F-F
Irregular Channel
Manning's Formula
Water Elevation
Section Data
Wtd. Mannings Coefficient
Channel Slope
0.013
0.50 %
Water Surface Elevation
40.85 ft
Discharge
3.81 cfs
43.
43. C
42.5
1 v 42.0
c
0
YT
,V
W 41.5
1 .
41.0
' 40.5
40.0 L
0.0
11 /23/99
t7:55:45 AM
5.0 10.0 15.0 20.0
Station (ft)
Hassled Methods, .Inc: 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
25.0
FlowMaster v5.15
Page 1 of 1
' Section F-F in Basin 204A
' Worksheet for Irregular Channel
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
Section F-F
Flow Element
Irregular Channel
Method
Manning's Formula
Solve For
Water Elevation
Input Data
Channel Slope
0.50 %
Elevation range: 40.38
ft to 43.23 ft.
Station (ft)
Elevation (ft)
Start Station
0.00
43.23
0.00
10.72
40.55
10.72
11.72
4.0.38
12.72
12.72
40.55
22.66
42.05
Discharge
3.81 cfs
Results
Wtd. Mannings Coefficient
0.013
Water Surface Elevation
40.85
ft
'
Flow Area
1.27
ft'
Wetted Perimeter
5.32
ft
Top Width
5.23
ft
'
Height
0.47
ft
Critical Depth
40.87
ft
Critical Slope
0.004385
ft/ft
Velocity
3.00
ft/s
Velocity Head
0.14
ft
Specific Energy
40.99
ft
'
Froude Number
1.07
Flow is supercritical.
1
1
End_ Station
10.72
12.72
22.66
Roughness
0.030
0.013
0.030
11 /23/99
�07:56:34 AM
FlowMaster v5.15
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1
Section G-G
Cross Section for Irregular Channel
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
Section G-G
Flow Element
Method
Irregular Channel
Manning's Formula
Solve For
Water Elevation
1
Section Data
Wtd. Mannings Coefficient
0.014
Channel Slope
1.00 %
Water Surface Elevation
42.23 ft
Discharge
9.92 cfs
42
42
V 42
c
0
lL 42
42.
41.
41._
0.0
5.0 10.0 15.0 20.0 25.0 30.0
Station (ft)
Kwel
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMaster v5.15
Page 1 of 1
I
U
Section G-G in Basin 203
Worksheet for Irregular Channel
Project Description
Project File
f:\programs\haestad\fmw\tcreek.fm2
Worksheet
Section G-G
'
Flow Element
Method
Irregular Channel
Manning's Formula
Solve For
Water Elevation
Input Data
Channel Slope
1.00 %
'
Elevation range: 41.83
ft to 42.50 ft.
Station (ft)
Elevation (ft)
Start Station
0.00
42.50
0.00
1
12.32
42.08
12.32
20.32
42.00
22.31
21.32
41.83
22.31
42.00
33.28
42.50
Discharge
9.92 cfs
Results
Wtd. Mannings Coefficient
0.014
Water Surface Elevation
42.23
ft
Flow Area
3.10
ft'
Wetted Perimeter
19.58
ft
Top Width
19.54
ft
Height
0.40
ft
Critical Depth
42.28
ft
Critical Slope
0.004955 ft/ft
Velocity
3.20
ft/s
Velocity Head
0.16
ft
Specific Energy
42.39
ft
Froude Number
1.42
Flow is supercritical.
End Station
12.32
22.31
33.28
Roughness
0.030
0.013
0.030 .
I
11 /23/99
' 08:05:46 AM
Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666
FlowMaster v5.15
Page 1 of 1
APPENDIX C
EROSION CONTROL CALCULATIONS
I
I
I
N
N
a
4
e
�
r
i
O
U.
p
K
¢
a
e
a
z
¢ F
vFi Q
r
h
•
�n
T
n
N
a
�
rn
rn
P
o
0
a
Ln
o
T
U)
Y
Y
V
U
a
u
U)LO
o
L
V
�
a
�
t7
vi
a
E"F
r
�
r
F
m
,
d
e�
m
Z
w
F 4
m
G
Lzi
y
Z
m
g
N
O
F
N
a U
� a
O C .>
� � C
,o
5 a
-0 N Y
L
p— a
�a
� C N
G y °
�s
U L
C cv
y O N
c O
N r-: —
E
OV
y
C +O+
O Q y
E
00
En
m
L ti
I0
W N O
0 0
°
co c >
0 0
Ca) to
cn��¢Q
:° 0 3
II II II
II II
� W
Q.av�.acn
a¢
y
X
c
0
0
w
North Star Design
1200 Carousel Drive, Suite 201
Windsor. CO 80550
EFFECTIVENESS CALCULATIONS
PROJECT:
Townhomes at Timber Creek
STANDARD FORM B
COMPLETED BY:
PPK
DATE: 12-Sep-99
EROSION CONTROL
C-FACTOR-
P-FACTOR
METHOD
VALUE
VALUE
COMMENT
BARE SOIL
1.00
1.00
SMOOTH CONDITION
ROUGHENED GROUND
1.00
0.90
ROADS/WALKS
0.01
1.00
GRAVEL FILTERS
1.00
0.80
PLACED AT INLETS
SILT FENCE
1.00
0.50
STRAW MULCH
0.06
1.00
ESTABLISHED GRASS
0.08
1.00
FROM FIGURE 8-A
STRAW BARRIERS
1.00
0.80
EFF = (I -C*P)* 100
MAJOR
SUB
BASIN AREA
EROSION CONTROL METHODS
BASIN
BASIN
(Ac)
203
1.51
ROADS/WALKS
0.54 Ac.
ROUGHENED GR.
0.00 Ac.
GRAVEL FILTER
0.27
STRAW/MULCH
0.70 Ac.
NET C-FACTOR
0.21
NET P-FACTOR
0.91
EFF = (1-C* P)* 100 =
80.9%
202, 204a
3.55
ROADSIWALKS
1.18 Ac.
ROUGHENED GR.
0.00 Ac.
STRAW/MULCH
1.56 Ac.
SILT FENCE
0.00
GRAVEL FILTER
0.81
NET C-FACTOR
0.26
NET P-FACTOR
0.95
EFF = (17C*P)* 100 =
75.4%
TOTAL AREA = 5.06 ac
TOTAL EFF = 77.0% _ (94.0%*29.77 ac. +.. +99.6%*0.40 ac)/I. 14 ac
REQUIRED PS = 76.7%
Since 77.0% > 76.7%, the proposed plan is o.k.
1.22
2.68
3.90
Erosion.xls . 1 of 1
North Star Design
1200 Carousel Drive, Suite 201
Windsor, CO 80550
CONSTRUCTION SEQUENCE
STANDARD FORM C
PROJECT: Townhomes at Timber Creek
SEQUENCE FOR 1999 ONLY COMPLETED BY: PPK DATE: 12-Sep-99
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.
MONTH
1999
J1
F
M
A
M
J
J
A
S
0
N
D
Demolition
Grading
Wind Erosion Control:
Soil Roughing
Perimeter Barrier
Additional Barriers
Vegetative Methods
Soil Sealant
Other
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/Blan kets
Other
BUILDING CONSTRUCTION
STRUCTURES: INSTALLED BY: CONTRACTOR MAINTAINED BY: DEVELOPER
VEGETATION/MULCHING CONTRACTOR: TO BE DETERMINED BY BID
DATE SUBMITTED: APPROVED BY CITY OF FORT COLLINS ON:
Page 1
Cost Est
EROSION CONTROL COST ESTIMATE
Project: Townhomes at Timber Creek
Prepared by: PPK
ITEM
IQUANTITY
UNIT
COST/UNIT
ITOTAL COST
Silt Fence
380
LF
$3
$1,140
Straw Bale Barrier
EA
$150
$0
Gravel Inlet Filter
3
EA
$150
$450
Construction Entrance
1
EA
$550
$550
Subtotal
Contingency (50%)
Total
$2,140
$1,070
$3,210
CITY RESEEDING COST
Reseed/Mulch
5.06
ACRE
$650
$3,289
Subtotal
Contingency (50%)
Total
$3,289
$1,645
$4,934
EROSION CONTROL ESCROW AMOUNT $4,934
Page 1
APPENDIX D
EXCERPTS FROM PREVIOUS REPORTS
v
FINAL DRAINAGE AND
EROSION CONTROL. STUDY
FOR
TIMBER CREEK
P.U.D.
FIRST FILING
FORT COLLINS, COLORADO
July 1, 1994
Prepared for:
Everitt Companies
3000 South College Avenue
Fort Collins, Colorado 80525
Prepared by:
RBD, Inc. Engineering Consultants
209 S. Meldrum
Fort Collins, Colorado 80521
(303)482-5922
RBD Job No. 035-134
D. Hydraulic Criteria
All calculations within this study have been prepared in accordance with the City
of Fort Collins Storm Drainage Criteria.
E.. Variances from Criteria
Due to the way in which the SWMM model was originally used by RBD and then
revised per the City of Fort Collins Stormwater Utility's request, detention pond
number 373 is seeking a variance for the amount of water it is releasing into the
McClellands Basin Drainageway.
W. DRAINAGE FACILITY DESIGN
A. General Concept
Developed flows for most of Timber Creek P.U.D. will be routed by an open
channel to Detention Pond 373, located at the southeast corner of Stetson Creek
.P.U.D.. Detention volume has been provided in this pond for those areas of
Timber Creek. Approximately 14.5 acres along the easterly portion of the project
will be routed to pond 374, and detained in that pond.
B. Specific Details
Approximately 100 acres north of the proposed Timber Creek development
historically flows south across this project to the McClellands Drainageway. The
historic flows from this property will sheet flow to a temporary interception ditch
which parallels the northerly property line of Timber Creek. These historic flows
will be routed south along the easterly property line of Timber Creek and Stetson
Creek, and through Detention pond 373, and released into the McClellands
Drainageway. As development occurs on this property, on -site detention will need
to be developed. As this is a temporary interception swale only, no permanent
concrete trickle channel has been designed into this swale, although the
longitudinal slope is only 0.5%.
Approximately 2/3 of the westerly portion of this project will be routed to and
detained in Detention pond 373. Sub Basins 202 and 203 were considered as
future Multi -Family. Sub Basin 201 is a portion of Timberline Road adjacent
to this site, and will flow to Timber Creek Drive. A small portion of
Timberline Road (Sub Basin 520*) adjacent to this site will flow south along
Timberline Road to the entry to Stetson Creek, and then on to Detention
Pond 373.
4
' The final design of Timberline Road north of and adjacent to this site
(currently being designed by Northern Engineering Co. Inc.) will include curb
inlets just to the north of developed basin 201 and immediately west of the
' temporary drainage swale along the northerly property line. These curb inlets
will intercept all developed flows from Timberline Road north of this project,
and route them easterly in the temporary drainage swale north of the property,
' and then south to Detention Pond 373. The temporary drainage swale north
of Timber Creek will stay in use until Basin 101 is developed.
' Approximately the easterly 1/3 of the project will be routed to and detained
in pond 374. Detained flows will be released into an open channel along the
easterly property line of Timber Creek and Stetson Creek, routed through
Detention pond 373, and ultimately into the McClellands Drainageway.
' High groundwater might be encountered during construction, and an
underdrain will be constructed. In addition, a Colorado Department of Health
Construction Dewatering Permit will be required.
SWMM Modeline
In order to analyze the ultimate permanent detention ponds within the Stetson
Creek and Timber Creek developments, the Urban Drainage District's SWMM
routing computer model was required to be used by the City of Fort Collins
Stormwater Utility. As part of the McClellands Basin Master Plan, a SWMM
model was developed for this basin, but the original SWMM Model was not
available from the City of Fort Collins Stonnwater Utility for utilization with this
project. Because the original SWMM Model was not available from the City, the
upstream Oakridge development existing 10 and 100 year SWMM Models were
utilized and added onto for this developments analysis. A schematic of the
original Greenhorn and O'Mara and Oakridge development SWMM models are
included in the Appendix. Included in the back pocket of this report is a new
SWMM Model Exhibit drawing for the area directly east of the Oakridge
development to the east property line of the Stetson Creek and Timber Creek
developments.
The Oakridge development SWMM model was added onto for the property within
the basin between the Oakridge development and the eastern property line of the
Stetson Creek. and Timber Creek developments, including the new proposed
Harmony Crossing P.U.D. development. The Harmony Crossing P.U.D.
development Final Drainage and Erosion Control Report contains information on
basins and conveyance elements added onto the SWMM model between the
Oakridge development and Timberline Road.
5
�l
t/
Y
N
t�
cr-r
r
r
a
r
d
r
r
fo
V
q
w
Q 1
dL
zu
du
o
o
�w
qq
d
0
a�
11
0
N
�1
as
r]
��
*
n
11
UU
p
O
O
4L
6
6
0
O
O
�-
��'"�r�
Ui
Q
a
ll,
0=
o
I w
J o
U'
1f1
U /
�
�J
►-
N—
i
Q) ti
zLLJ
fn
N
Z�.
a
N
r
7t
W,
>�.
W
o ,
_
0
0
0
0
0
o
a
o
0
o
0
0
0
0
ow
N�
=
N
N
N
N
N
N
N
N
N
N
N
N
N
N
~~W��
z
00
��
nn
��
v
z
o
Q
O
O
Q
p
V)
a�
r
c
ei
r�
N
r
of
N
r�
T
nn
U.
r
Ll
M
—
—
r-
—
—
o
W
I
cn U
0
0
a
r.
L
mo
��
U OU
O
9
m
0
W
tLi a-
>�
LLJ
Q�
a0
co
cn
No
fl0
O
o
o
p
J
0
a^
t+l
d
to
9
O
cO
0
J
c0
0
QdUJ
(�
ov
oa
N
N
N
N
N
N
N
N
N
N
N
N
N
w
z
J��°8°°���n�°���
^
M
1
z
O
o
o
Q
QQ
m
a
9
N
d
H
w u—
m in
1.1
N
�J
N
N
to
U
z
c,
z
W
W
z
5
z
J
Y
CC
S4/
COMPOSITE "C" VALUES FOR TIMBER CREEK P.U.D.
Prepared by: Bud Curtiss Date: March 2, 1994
RBD, Inc.
IMPERV
IMPERV PERVIOUS
RUNOFF
BASIN
AREA
AREA (AC)
C.
"C"
COEF
204
1.31
0.33
0.95
0.25
0.43
205
3.00
0.86
0.95
0.25
0.45
206
1.65
0.57
0.95
0.25
0.49
207
0.70
208
2.76
1.09
0.95
0.25
0.53
209
2.19
0.75
0.95
0.25
0.49'
210
3.56
1.21
0.95
0.25
0.49
211
1.78
0.59
0.95
0.25
0.48
212
3.12
1.02
0.95
0.25
0.48
213
0.24
0.00
0.25
0.25
214
3.14
0.22
0.95
0.25
0.3004
215
2.92
0.87
0.95
0.25
0.46
216
2.94
0.98
0.95
0.25
0.48
217
0.53
0.23
0.95
0.25
0.55=:f
218
0.98
0.34
0.95
0.25
0.49
219
0.40
0.03
0.95
0.25
0.30
220
1.08
0.11
0.95
0.25
0.32
221
0.38
0.06
0.95
0.25
0.36
22.2
2.83
1.01
0.95
0.25
0.50
223
1.94
0.47
0.95
0.25
0.42
224
2.16
0.78
0.95
0.25
0.50
225
1.74
0.61
0.95
0.25
0.50
226
1.60
0.51
0.95
0.25
0.47
227
1.71
0.51
0.95
0.25
0.46
228
2.34
0.10
0.95
0.25
0.28
229
2.41
0.06
0.95
0.25
0.27
521
0.60
0.00
0.95
0.25
0.25•.a
`, II
,o
IVOLE___..C__
VA.LUEs.
USED iLL
6E
O.So
UQL,.-Ss
oT�FEtZ`vis� SHowr.l
RINC
CLIENT ?Tr ( •ram
JOB NO.
/1
PROJECT _. 11 M e�E--V,- (I PCB
✓_ �T '
- CALCULATIONS FOR ` f ^.^.^.?
Engineering Consultants
MADE BY -DATE CHECKED
By- DATE SHEET -OF
i
.e7dSl �15; z01, 2nz� Zo3 ; 5i+ow1V oil
c
TIM._ aF.Corx�Nr�.�T1c7+.1.
i SljMc
:. 7
:
I
L------------
sr
-7d� L..or I M PE
S. ZV IOL�S
'S 1 o E�a!•vUc �
I
i
!
1
i
Zc� :
I-7 I-74-Z
l ,� 4 F.2uN�sj Z gods
i
54-3 . ;
9 � 1 ` r- �o,�► r
Zlo :
Z3,89q
I
i' - l-7
Zz
-7
Z13
�.-U, 't'�22vious
i
IZfsis-,
.
Zip
Z'9 1
z 6 1
I
I
j
ZZ I
I
�
,
ZZZ
ZS, IGG
Z23
io%o
Zz4
20714
S4-
--Z2
STORM DRAINAGE SYSTEM PRELIMINARY DESIGN DATA
Flow Time
Location Street: pipe Sireet Pipe
E,
Cf..
z Z,
Design Point u 0'.
0 0 E
r
W - 0 0
72 D-- 0 E CL A
�3 E u :3 M = -j E. 0 0. 0 CL
amu Oct V) a: Cl) a a 0 CL
a < Q V) cn C
< ci
5 6 7 >
3
8 9 10 11 12 13 14 15 16 17 18 19
20 2,1 22
F51.9 0.2e) 2.92 99,0 72.3 7Z.3
201 5.5 0,S-7 8.1 I.D4- -7.a-7 -7.51 Z. 0 732
ZoZ 7. 6-7 2,9
202- z 8.9 0,51 7.6 -Z,9p�
0, B-Z -7.6 4.oz
2G,.CG O.S9 5 4�9
-7, Bs o. e�s s4-,-�
Z04- 5.0 0-71 -7.9 1-31 -7,32S -7.35
g55 4
11-1 O.So 6.9 -5,3-3 29-47- 29.4z C) SS ?4.C>
205
29.4Z
13.-6
zo 19 55 54-19
4:
4-l" JE)/Z D.74 fb, to 26). 60 Z06 1 � * 0. e7s 34-14)
0-62 5 6,4S 1,6�5 6.65 C). ss e4-9
-S,7� 9.9s 7-,5.ss �74 '25.61 0.5e, 34.9
ZD6 7.--
Z; 73 5,7& 1
Oman
RM
M�
mmmmm
EM
OMMUM1=1
0�m
M311=1
Emm
I=
on
mmm
M
1WA
1=1�ml
M
-0
�11�11=11=11ml
mmm
MIMM
mmm
mom
` -
. _.:
�����
���
Zvi
i�ii
i
i����si�°
mom
IBM
NE"..
im
MOM
10=11M
may._ g. �z�-,ss ----�_ ice,.,-� Iz • z�
STORM DRAINAGE
SYSTEM PRELIMINARY DESIGN DATA��
Location
0 i
Point
y
C
`
�.
d
v
E
Flow Time
o
C
00
C
C7
in
_
o
m VI
:
L y
uE
y
o ,..
E o
C
Street
Pipe
Street
Pipe
Remarks~
i_
G
ov
06
0.
oa
G y
O
no�i
N
oDesign
.
C
'
40
ym
i
Dnu
I
2
3
1 4
5
6
7
8
1 9
10
11
12.
13
14
15
16
17
18
19 1
20
21
22
23
Zc�1
7.
0.7o
2,3o
1.04
Z,04-
Z.o4-
Z.co
14-.7
Z.c*
Z.9-
ZoZ
11.4
o.65
2.3o
2,98
4.41.
4.46
O.SS
7.0Z
4.46
I
Zo2-.
2A1,
Z
II ,4
CM 6
Z.30
4.oZ
6.10
6.10
0•sS
7.OZ
6.10
204
10.1
O.SI
2.50
1.31
1.5?
I.57
0,-E75
7.0Z
(.87
I.(-
-ea,ueL-T,MaTo Op. zx>6-- Z.Z�n��l.
�4
201,20
,2p¢ .
2.2
13.6
D.64
Z. to
e%S3
-7. 1(.:,
"1. Ito
O,SS
7.oZ
-7, IL�
1.6
ZoS
15•B
D.SI
Z.OS
3,co
3.(4-
3.14
O.SS
7.0Z
3.14
1.6
TIE-&uGJ-rlenevZ) Dpz_06- 4.1 r11Q.
205
20I ZO
,Zn4 zde>
4.1
-3
1-7-7
O.5r-i
I .95
6.33
9.
5-(.Z
0.5
%.OZ
5.6Z
1.6
CDMP Q : 6.33X0.64��i3•oo�(D.51 g33
cis iorEzc6-,rED IN S' %%jusT
ZDb
14.9
O.SO
2.10
I •c-e
1.75
1.73
D.53
-7.0Z
1.7B
1.6
DP 20(=- 4,4-µ,J
2Ob
Zo1.20
.20a.
d.4
---+
ZZ.I
D,5B
105
9.90>
II).13
57i9
4.34
0-SS
-7.oZ
4.b4-
t.�
�pry1pC= 5.33 0.� + 1•es 0,�
5.98
2D6
To l-,Ow Fbirsr -4 .Surma IQ Lr--T
�Zo
57�
&.e
0,7o
Z.BS
p,48
0.96
0.96
1.0
10,ez
1.28
Z.o
T� SrG�ov l vt c✓ P. u. o.
Zt 3
0,53
2.00
Z 710
2.93
2.9 3
0.55
7. OZ
2 A3
1. (v
I
209
19,1
O.ex.)
1,90
2.19
2,05
2-OS
0,45
3.Zb
Z.O!E,
1. is
ZOI=�
Zoe. .
19.1
O . S2
1.90
4 9S
4, ER
4.99
0, 55
-7. DZ
4. 89
1 - 6
210
20.4
0. ao
1.60
3.56
3. Zo
3 • Z.o
0,215
S.o9
210
203.zC9,
ZIO
2o,4
0. E51
I.Bo
sl
7.51
7:s1
C-SEd
7,02
7.81
1 _C.
4. cz�5 1&ezc.epT�,-o 1Q id luteT-
15.
O. S0
Z • .10
1.-7LS
1.20
1.87
0. 55
7.OZ
1 .67
1. 6-
i
7P-Au'1_ L. TI MS "To OP 2-1 l - 49 M A.
ZII
?C(3
2�,21
4.9
Z5,3
0,51
1.7o
i0.Z9
8.9Z
4.16.4.76
0.55
7.dZ
4:-76
1.0
To some tQL.ET
SZ►
I .6
D.Z5
2.45
aa60
0,37
0,37
I
PLOIuo to e&siv SZl.s7aTbo�tcezey-
Z03
Zo3
10. 3
0.&5
2,45
1.4Z
Z.2b
Z6
2.Zt=
-rime •ro DP ZIZ - S.Z
Z I Z
IS-4-
0- 50
2.10
B . 1 Z
3.28
5-76
0. 60
37
1 • �
�
21z
Zo3,?1
S.Z
1=o.s
0.55
2.10
4.54
5,24
5.24
0.60
5.37
5.'71'r
I
I.az o.bs + a.Iz
TO SloSwAnl r cuurEzr
O,IDD
Z,90
0.38
O.S5
O. Sr
'644E , aCui TO STa7�C>Q C-e.P-rx
Z14-.
16•o
0.39
2.oS
3.14
2.Sf
Z:S1
_
Te-44 L'TImE'to Do 2l -7-2- m.J
214
Z03,217,Z14
ZZ
ZZ,7
O,rr3
I.7o
-1.68
(o27
(O.Z7
CC>Cjp0_° L4.54 0,ss + 3, 14-X 0.39
-
="
7.L$
41
Pa
I'M
Frir.
nrl
z' X
1w
WON
r-
7
i.
ME3r�c
- It
ME3r�c
- It
APPENDIX E
FIGURES AND TABLES
E
No Text
DRAINAGE CRITERIA MANUAL RUNOFF
5
30
I- 20
Z
W
U
cc
W
CL 10
Z
W_
a
O 5
U)
W
'
3
O
V
2
W
F
3
'
1
5I
�MEn���n�����
�M0111111I�//�I,I,IIIII/
soil
�irrii►',�
.�■
Its■�_
_�tt■tt�
tlttM■�
/tl/.■N►I
tt
I�MMMM■►I
■
MMMEME■�
.1 .2 .3 .5 1 2 3 5 10 20
' VELOCITY IN FEET PER SECOND
F►GURE 3-.1 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 6 FLOOD CONTROL DISTRICT