You can copy from here when filling out the rest of the page.
The District Engineer, U.S. Army Engineer District, Omaha, Nebraska is evaluating a Department of the Army Section 404 Permit application from the Urban Drainage and Flood Control District (UDFCD), 2480 West 26th Avenue, Suite 156-B, Denver, Colorado 80211, c/o CORVUS Environmental Consulting, LLC, Attn: Mary Powell.
UDFCD is proposing flood control improvements along City Park Channel to the confluence of Big Dry Creek. The project, as proposed, will permanently impact 1.27 acres of wetlands and temporarily impact 0.13-acre of wetlands and 250 linear feet (0.09-acre) of Big Dry Creek.
PUBLIC NOTICE
US Army Corps
of Engineers
Omaha District
REPLY TO:
Denver Regulatory Office
9307 South Wadsworth Blvd
Littleton, CO 80128-6901
FAX (303) 979-0602
Application No:
Project:
Applicant:
Waterway:
Issue Date:
Expiration Date:
NWO-2017-00648-DEN
City Park Channel Phase 2
Urban Drainage and Flood Control District
City Park Channel
June 28, 2017
July 28, 2017
30 DAY NOTICE
PUBLIC NOTICE
FOR SECTION 404 PERMIT APPLICATION SUBMITTED TO
U.S. ARMY CORPS OF ENGINEERS
Notice
The District Engineer, U.S. Army Engineer District, Omaha, Nebraska is evaluating a Department of the
Army Section 404 Permit application from the Urban Drainage and Flood Control District
(UDFCD), 2480 West 26th Avenue, Suite 156-B, Denver, Colorado 80211, c/o CORVUS
Environmental Consulting, LLC, Attn: Mary Powell. Permits are issued under Section 404 of the
Clean Water Act (Section 404) which regulates the placement of dredged or fill material in the nation's
waters.
Summary
UDFCD is proposing flood control improvements along City Park Channel to the confluence of Big
Dry Creek. The project, as proposed, will permanently impact 1.27 acres of wetlands and temporarily
impact 0.13-acre of wetlands and 250 linear feet (0.09-acre) of Big Dry Creek.
Location
The project is located in Sections 5 and 6 within Township 2 South and Range 68 West in Broomfield
and Adams Counties, Colorado. The approximate project center latitude is 39.914075 and the
longitude is -105.034427.
Existing Conditions
The project area is within the northwest Denver Metropolitan Area in the Big Dry Creek watershed.
Development within this watershed has increased the amount of impervious surfaces, which has
Page 1 of 11
Corps of Engineers' Section 404 Public Notice: City Park Channel Improvements Phase 2
Corps File No: NWO-2017-00648-DEN
Waterway: City Park Channel, Broomfield and Adams Counties, Colorado
Applicant: Urban Drainage and Flood Control District
resulted in higher stormwater volumes. In 2009, the UDFCD constructed a portion of the stormwater
channel (Phase 1), which was proposed to convey the 100-year flood flows, but currently only
conveys water in large events. The Phase 1 section of channel flows through an existing box culvert
under 120th Avenue. Currently, during flood events, flows within the City Park Channel inundate
120th Avenue.
Description of Work
The proposed project has two main components: 1) to construct an extention to the Phase 1 section of
channel to converge with Big Dry Creek to the east (overflow channel); and 2) restrict the peak flows
from entering the northern channel so that only baseflows are allowed passage. The goal of the flood
control improvement project is to allow for sufficient flow to maintain the vegetation and riparian habitat
within Metzger Farm Open Space and the City Park Channel to the north of 120th Avenue; to provide
water quality benefits within the Metzger Pond by reducing sediment deposition during flood events;
flood flows toward the Metzger Pond dam would be significantly reduced and would reduce the risk of
overtopping the of dam; and the peak diversion flow to the north side of 120th Avenue would be
contained within the existing channel.
Project Purpose and Need
The basic project purpose is flood control. The overall project purpose is to address safety concerns
associated with flood conveyance and protect the existing infrastructure and private property, as well
as improving the aquatic ecosystem of the Metzger Farm Ponds.
Impacts and Mitigation
The proposed flood control project would require the unavoidable discharge of fill material into
waters of the U.S. and abutting wetlands associated with Big Dry Creek within the project area.
Following are the approximate amounts of fill that would be permanently placed within waters of the
U.S., including wetlands:
215 cubic yards of concrete
150 cubic yards of grouted boulders and bedding
530 cubic yards of void-filled soil riprap
The project would result in 895 cubic yards of fill material. Unavoidable permanent impacts to 1.27
acres of wetlands associated with flood control improvements is proposed. Temporary impacts
include 0.13-acre of wetlands and 250 linear feet (0.09-acre) of Big Dry Creek. Permanent impacts on
waters of the U.S. primarily consist of the construction of the overflow channel to converge with Big
Dry Creek. Unavoidable temporary and permanent impacts would occur to additional portions of the
project area as construction vehicles access the project area during construction to conduct the flood
control improvements.
The proposed project has been designed to minimize impacts to Big Dry Creek, and its associated
wetlands to the greatest extent practicable. In addition to avoiding and minimizing direct impacts, the
project would include best management practices (BMPs) during construction to minimize indirect
impacts on adjacent areas. Standard BMPs, including sediment-control logs, construction fencing,
Page 2 of 11
Corps of Engineers' Section 404 Public Notice: City Park Channel Improvements Phase 2
Corps File No: NWO-2017-00648-DEN
Waterway: City Park Channel, Broomfield and Adams Counties, Colorado
Applicant: Urban Drainage and Flood Control District
vehicle-tracking control at the entrance, and temporary rock check dams would be used to reduce
impacts outside of the project area.
As proposed, temporary and permanent impacts on waters of the U.S. and adjacent wetlands would be
mitigated for on-site, in-kind, and at a 1:1 ratio using a combination of restoration, compensatory
mitigation, and improvements to the aquatic ecosystem.
*********************
The Colorado Department of Public Health and Environment, WQCD-GWPS-B2, 4300 Cherry Creek
Drive South, Denver, Colorado 80222-1530, will review the proposed project for state certification in
accordance with the provisions of Section 401 of the Clean Water Act. The certification, if issued, will
express the State's opinion that the operations undertaken by the applicant will not result in a violation of
applicable water quality standards. For further information, please contact the Colorado Water Quality
Control Division at (303) 692-3500.
In compliance with the Endangered Species Act, a preliminary determination has been made that the
described work will not affect species designated as threatened or endangered or adversely affect
critical habitat. In order to complete our evaluation of this activity, comments are solicited from the
U.S. Fish and Wildlife Service and other interested agencies and individuals.
The Corps of Engineers, Omaha District will comply with the National Historic Preservation Act of
1966, and amendments and the procedures set forth in 33 CFR 325, Appendix C. The Corps will
evaluate input by the State Historic preservation Office, Tribes, and the public in response to this
public notice, and we may conduct or require a survey of the permit area to check for unknown
historic properties, if warranted.
The decision whether to issue a permit will be based on an evaluation of the probable impacts including
cumulative impacts of the proposed activity on the public interest. That decision will reflect the national
concern for both protection and utilization of important resources. The benefits which reasonably may
be expected to accrue from the proposal must be balanced against the reasonably foreseeable detriments.
All factors which may be relevant to the proposal will be considered including the cumulative effects
thereof; among those are conservation, economics, aesthetics, wetlands, fish and wildlife values, flood
hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water
supply and conservation, energy needs, safety, food and fiber production, mineral needs, considerations
of property ownership and, in general, the needs and welfare of the people. In addition, the evaluation
of the impact of the work on the public interest will include application of the guidelines promulgated by
the Administrator, Environmental Protection Agency, under authority of Section 404(b) of the Clean
Water Act (40 C.F.R. Part 230).
The Corps of Engineers is soliciting written comments from the public; Federal, state and local agencies
and officials; Indian Tribes; and other interested parties in order to consider and evaluate the impacts of
this proposed activity. Any comments received will be considered by the Corps of Engineers to
determine whether to issue, modify, condition or deny a permit for this proposal. To make this decision,
comments are used to assess impacts on endangered species, historic properties, water quality, general
Page 3 of 11
Corps of Engineers' Section 404 Public Notice: City Park Channel Improvements Phase 2
Corps File No: NWO-2017-00648-DEN
Waterway: City Park Channel, Broomfield and Adams Counties, Colorado
Applicant: Urban Drainage and Flood Control District
environmental effects, and other public interest factors listed above. Comments are used in the
preparation of an Environmental Assessment and/or an Environmental Impact Statement pursuant to the
National Environmental Policy Act. Comments are also used to determine the need for a public hearing
and to determine the overall public interest of the proposed activity.
Comments, both favorable and unfavorable, will be accepted, made a part of the record and will receive
full consideration in subsequent actions on this application. Any agency or individual having an
objection to the work should identify it as an objection with clear and specific reasons. All replies to the
public notice should be sent to the U. S. Army Corps of Engineers, Denver Regulatory Office, 9307
South Wadsworth Blvd, Littleton, Colorado 80128-6901. For additional information please contact
Ms. Angelle Greer at (303) 979-4120 or visit the Denver Regulatory Office web site at:
http://www.nwo.usace.army.mil/Missions/RegulatoryProgram/Colorado/PublicNotices.aspx
The District Engineer will consider requests for holding a public hearing, for the purpose of gathering
additional information. Before the expiration date of this notice, anyone may request, in writing, that a
public hearing be held. Requests for a public hearing should state specifically the reasons for holding a
public hearing, and what additional information would be obtained. Should the District Engineer decide
that additional information is required and a public hearing should be held, interested parties will be
notified of the date, time and location.
Comments received after the close of business on the expiration date of this public notice will not
be considered.
Page 4 of 11
Corps of Engineers' Section 404 Public Notice: City Park Channel Improvements Phase 2
Corps File No: NWO-2017-00648-DEN
Waterway: City Park Channel, Broomfield and Adams Counties, Colorado
Applicant: Urban Drainage and Flood Control District
I
t..1...1t1 i·
\'i st.1
~ . R ·I.Jim
OWaler Tr !Ill
FaoU;
i
t
"
-.
·'·"
' I
I
,.\11 ,\"I :-.
_I,
Metzger, Farm
Open"sp'ace
fl .,,,
I eo 11 1 I
, ,~ (
' .
n.c1~
C 1 1 'Ti rnU 1 ~ t v
O flYHUll lll
,- ....
;·~
\'1
,,. '". t-.
,ti
l? i~.;
:1
VI 1111'1 r l
ti '
·'o:, uon.~'I
· 0111-.. 11
:'j.J/(Jll
~J.
'
'
ri)
~
l. e ('.·'l)'
f\~ '·
l~H I
l. 1.·t~·H)'
f\',' ij
'-1!"· /:
L
(\\' "" ' ol
lt1 g1·
re
~
\)
u
'f!
e
Q
Northwest
Open ..Space
j'I
\'i 1100,
"''
g'.I;,
·~
R.hl et:
,
\·1 1 lllh
I
I
..\
c 1.1ll
« /
:JO
·
Gol#' io
~
c,:· \
\, ,,.,(
'·"···I
I' I,,
f
Jo
Ano \
'
Ii! I ·I
\?,,_
CH2MHill
,_I_ _ __,I
0
City Park
Channel Improvements
Phase 2
CJ Study Area
0
=
City/Town
Interstate Highway
U.S. Highway
Regional Map
Figure I
State Route
1,000
feet
2,000
Coonl irm.eSyitem:
NAO 1981 Smef'llne Co!on.&I Celllral FIPS OS02 f ttt
ProjectJon:Umben:Confotm1ICooic
Ou um: North Ame riun 19!1
Hip Dne.:llln0 16
Re gional Map
\
\
120TH AVENUE
RIPRAP EXTENTS , TYP.
120TH AVE CULVERT~
l
~ ·-· - ·-·-·-·-·
......
-"-·
·-·~·-·
·--.....
. .~·
WW
-
-
-
'
\
7
~-~
-
\
-·-·-·-·-·\
!
\
UPSTREAM
PROJECT
LIMITS
-
I
-
PROPOSED
CITY PARK
DRAINAGEWAY
-·-·-
·\-.LI~~~
-.-·-·-·
CONSTRUCTION
'I
\
\
"
.
VICIN ~ MA~
LEGEND
~
Proposed Contours
~~~
UWl..'"-'-'l..JJ
L: J
"·
Impacted Wetlands
RipRap Extents
Existing Contours
Limits of Construction
1. ·~
0
30
60
111111 If 11 11
Feet
I
\)
Br;:idburn
"'
·'
.,
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 1
"I~
L!
120TH AVENUE
LIMITS
CONST~~CTION ' \ .
-
· -·- · -
-
~
I :"-a " ·
· ·- · __,:- · -
:-: -
:::
-
·
-~
i_RIPRAPEXTENTS , TYP.
-·-· ·-·--·-·-·-· ·-·--·-·-·-·
·.,
.
,-
..
~
~
[
~ · [!
1
- I.
\
"-..,. '
'Fl
I.
"
=. -.-.-.-.-·. --;-. .~~=s~:~o=~R-. .-·-.
'·
-
-:l:T~-;-.
PROPOSED
CITY PARK
DRAINAGEWAY
N
l.
I.
EDGING, TYP.
-·
I
EXISTING
VICIN~rv MA~
LEGEND
Proposed Contours
i .- .! Impacted Wetlands
RipRap Extents
Existing Contours
L: .J
0
30
Feet
60
''"'''l "!'ll 11 11 11 Ir 11 11
I
.,j
Limits of Construction
'
'
>
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 2
~
u
120TH AVENUE
I
I
LIMITS
CONSTRUCTION
OF
·-·-·-,.
I
...
.
-
I.
.
I
r
5
0
:i:
IP
m
r
r
~. - ·-\TIE INTO
DJ
<
c
EXISTING
I
'
LEGEND
VICINiTv MAf!
- - - Proposed Contours
I ·..I Impacted Wetlands
....................... RipRap Extents
Existing Contours
L: .J
Limits of Construction
0
30
60
,., l''l l ,,..,,II
11
II
11 Ir 11 11 I
Feet
I\
"'
Br.:tdburn
.··:
..
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 3
;~
0
120TH AVENUE
r
0
:E
m
"
r
r
OJ
~
c
VICIN jTv MA~
LEGEND
- - - Proposed Contours
I , .· · , I Impacted Wetlands
~~~
RipRap Extents
Existing Contours
L: .J
Limits of Construction
' ·
0
30
Feet
60
. "."l '"''l 11 11 11 Ir 11 1 I
Bradburn
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 4
I
....
120TH AVENUE
I
· ,..-
·-
I
a
·
\
\
LEGEND
VICIN rrv MAB
- - - Proposed Contours
Impacted Wetlands
LJU...ll....J..Jj..JJ
RipRap Extents
Existing Contours
L: J
Limits of Construction
0
30
60
. ",, l ,./1 1 II II II Ir 11 1 I
Feet
Br.:idbum
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 5
1 .·~
120TH AVENUE
PROPOSED DROP
STRUCTURE, TYP
I
PROPOSED
CITY PARK
DRAINAGEWAY
RIPRAP EXTENTS, TYP.
.
I
\
\
\
\
::T~·
7·-·-·-·-...... . . . ,
OF
CONSTRUCTION
PROPOSED TRAIL
VICINfTY MA~
LEGEND
- - - Proposed Contours
I> ·~ ~ I Impacted Wetlands
RipRap Extents
Existing Contours
L: J
Limits of Construction
0
30
60
. .ll'Oll' . '· '11111111ir1111 1
Feet
"
"
Br adburn
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 6
120TH AVENUE
.·-·-·--...... .... ..........
RIPRAP EXTENTS, TYP.
. --r·
..... 7
~
- ··- .- .- -·.- ,.. -:-
:··~>~)
-·-.
·~
.
~-
-<~- ~J ~--·
-.:= .;-
PROPOSED TRAIL
-·--·-·--·-·---·-·--·
.._
. .:__-.:.----7"'-------i
·- ·~
PROPOSED
CITY PARK
DRAINAGEWAY
.-- . ..........
-- .---- .
__..-._.......-·
--·-·-·
LIMITS
OF
CONSTRUCTION
VICIN lTY MA~
LEGEND
Proposed Contours
le:''~,_ I Impacted Wetlands
RipRap Extents
..,
L. _. Limits of Construction
Existing Contours
0
30
60
11 11 II ll 11 11
Feet
·,
Brodbum
·:
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 7
I
120TH AVENUE
I
-
1·-·-·-· ~·-·-·-· - ·-·1
'
', ,
I
(
',_
'",
'
I
I1
I
\
\
\
LIMITS
-
,
,
,
OF
.
i
1- - ~-;- ~~:~ . . ·. :-"-~~.~ .: ~ ~.. ~ · - · -
.I
-~
""'
\'ONSTRU,CTION, TYP - ·
·- ·-
\
·
~-~;.~<· ·.·!·:~;~";:: .:~,
·
-
·
-
~
·
·
-
·
-
· ·-
.
'
......... . ·.&-
· -~
·
-
·
-
·
I-~
4
·-j
......
~ ··
-
'I
-
·
-
lJ,11,
·
,,''.':''
, '/·
,
~ ·~
PROPOSED ~
CITY PARK .
DRAINAGEWAY
--- .
'
\:;
·
'
! (
I
·
\nf'I
)
.\- . - . . - .
-
\\\
i\
-
/
-
'/.
'·
'/
"
.\
! ~ -.-.:-.
'.··/
'\
. .· '
,.
,
~
''
I
)i) '
I ~
...
....
l
'
''
I
·-·--- ·-·-·-·---\
·--· ~
.....
I
·
.............. "
RIPRAP EXTENTS, TYP.
FEATURE BOULDERS , TYP.
I
\
'
'
LEGEND
.'
VICINITY MAP;
Proposed Contours Impacted
I'. ~~· : '. /
Wetlands and Other Waters
§
RipRap Extents
Existing Contours
i._ : :
Limits of Construction
0
30
60
Feet
Br adburn
FIGURE 4
Proposed Project Improvements
Impacts on Existing Wetlands
City Park Channel Phase 2
Page 8
8"'