Windy Gap Firming Project Wildlife Impacts
Sherman Hebein
NW Region Senior Aquatic Biologist
Ken Kehmeier
NE Region Senior Aquatic Biologist
Purpose of Windy Gap Firming Project
• Complete the existing project
• Make yield of project more reliable – “Firm
yield”
• DEIS constrained to impacts of Firming Project
Phase
Timeframe
Scoping Meetings
Fall 2003
Draft EIS
August 2008
Public Hearings
Oct 2008
Final EIS/Permits
Late 2010/Mid 2011
Design of Facilities
2011 - 2012
Construction
2013 to 2016
Windy Gap Firming Project Participants
Participant
Broomfield
Central Weld CWD
Storage
Request
25,200
330
Erie
6,000
Evans
1,750
Fort Lupton
1,050
Greeley
7,000
Lafayette
1,800
Little Thompson WD
4,850
Longmont
13,000
Louisville
2,700
Loveland
7,000
PRPA
Superior
Middle Park WCD
Total
12,000
4,500
3,000
90,180
Participant Demand vs. Supply
Firm Yield w/ WGFP – 170,000 af
• All Participants currently have water conservation programs and have
reduced per capita consumption by 26% since 1988
• Firm Yield from WGFP needed even with significant conservation
Alternatives in Windy Gap FP DEIS
1. No Action (13,600 af Ralph Price enlargement)
2. Chimney Hollow Reservoir – 90,000 af
3. Chimney Hollow Reservoir – 70,000 af plus Jasper
East Reservoir - 20,000 af
4. Chimney Hollow Reservoir – 70,000 af plus
Rockwell/Mueller Creek Reservoir – 20,000 af
5. Dry Creek Reservoir – 60,000 af plus
Rockwell/Mueller Creek Reservoir – 30,000 af
Year
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
1955
1954
1953
1952
1951
1950
Annual Deliveries (acre-ft)
Deliveries to WGFP Participants without Chimney
Hollow Reservoir
40000
Deliveries to Windy Gap Firming Participants (ac-ft/year)
35000
Note: Spill Years Shown in Red
30000
25000
20000
15000
10000
5000
0
Deliveries to WGFP Participants with Chimney Hollow
Reservoir
Deliveries to Windy Gap Firming Participants (ac-ft/year)
Deliveries w/o WGFP
Additional Deliveries w/ WGFP
Total Deliveries w/ WGFP
40000
Note: Spill Years Shown in Red
30000
25000
20000
15000
10000
5000
Year
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
1984
1983
1982
1981
1980
1979
1978
1977
1976
1975
1974
1973
1972
1971
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
1955
1954
1953
1952
1951
0
1950
Annual Deliveries (acre-ft)
35000
Demands and Depletions for Various Conditions
Condition
Average Deliveries
Net Depletions
EIS Model Results:
Existing Condition
No Action
Proposed Action
11,372
21,936
29,010
17,750
30,194
39,033
17,861
21,340
24,594
33,432
Historical Data (Actual numbers):
10-year Average (2000 – 2009)
5-year Average (2005 – 2009)
Previous Mitigation for C-BT Project
• Green Mountain Reservoir
• replaces out-of-priority diversions
• 100,000 ac-ft of storage for Western Slope use
• Minimum Flows below Granby Reservoir:
•20 cfs – September through April
•40 cfs – August
•75 cfs – May through July
• Improved diversion structures on Colorado River
near Kremmling
• All C-BT Obligations have been met for over 50 years
Previous Mitigation for Windy Gap
• $10.2 Million for Wolford Mountain Reservoir
• CDOW Recommended Minimum Flows:
• 90 cfs – below Windy Gap
• 135 cfs – below Williams Fork
• 150 cfs – below Troublesome Creek
• 450 cfs for 50 hours once every three years
• Diversion Limits:
• 600 cfs diversion capacity
• 90,000 ac-ft per year – maximum
• 65,000 ac-ft per year – 10-yr avg.
All Limits Will Be Met with WGFP
Western Slope Impacts
Aquatic Resources
• Decrease in the amount and frequency of available
fish habitat in the Colorado River at three sites
(Windy Gap to Williams Fork)
• 32% – 34% RBT adult, average year, late summer
• Increase in stream temperature (<1°C - 4°C)
• Lower water levels in
Granby Reservoir would
slightly reduce available fish
habitat.
• The species and
distributions of
macroinvertebrates are not
expected to change
Recreation
• Reduction in flows for kayaking and rafting in
Byers Canyon, Big Gore and Pumphouse
• Access to Granby Reservoir boat ramps at
Arapaho Bay, Stillwater, and Sunset could
diminish in some months.
Recreation (2)
• Effects on recreational fishing in the Colorado
River downstream of the Windy Gap diversion
from habitat loss and temperature impacts
between Windy Gap and the Blue River
Socioeconomics
• Lost recreational boating value in the
Colorado River (some years)
Alternative
Byers Canyon
(Kayaking)
Big Gore
Canyon
(Rafting and
Kayaking
Pumphouse
No Action
-$416
-$2,423
-$66,399
-$71,990
Proposed
Action
-$416
-$3,392
-$72,340
-$66,399
Kayaking
Rafting
• Reduction in aesthetic value in Grand Lake if
algae concentrations increase
• Shadow Mountain Reservoir
Stream Morphology and Floodplains
• Small decrease in frequency of 2-year peak
discharge and in channel maintenance flows in
the Colorado River
• Small decrease in frequency of 2-year peak
discharge and in channel maintenance flows in
Willow Creek
• Potential for flooding along the Colorado River
and Willow Creek would decrease
Surface Water Hydrology
• Reduced spills into Colorado River below
Granby Reservoir as a result of fewer Windy
Gap spills.
• Reduced flows in Colorado River below Windy
Gap diversion during runoff period when
pumping
• Lower water levels in Granby Reservoir as a
result of prepositioning
Surface Water Quality
• Colorado River temperature between Windy
Gap and Williams Fork may exceed 18.2 °C
chronic MWAT state standard as a result of
lower flows.
• Additional WGFP pumping would increase
nutrient loading in Granby, Shadow Mountain
and Grand Lake resulting in increased
chlorophyll a and Mn concentrations and
decreased DO levels.
Surface Water Quality (2)
• Decrease in Colorado River DO below Windy
Gap dam (0.1 ppm to 0.6 ppm)
• Higher concentration of nutrients in the
Colorado River as a result of Windy Gap
Firming Project pumping that reduces dilution
flows.
• Slight increase in nutrient and metal
concentrations in Willow Creek
T & E Species
• Depletion charges for Colorado River T&E fish
already paid to Recovery Program.
• State listed species are present in Colorado
River (RTC, FMS, BHS)
Ongoing Studies
• The following slides depict impacts to fish and
macroinvertebrates documented by CDOW
researchers and biologists.
• Information not contained in DEIS
Ongoing Studies
Ongoing Studies
Pteronarcys californica – The Giant Stonefly
Ongoing Studies
Pteronarcys californica population changes from 1980 to 2010
(individuals per square meter)
Site and distance downstream from Windy Gap dam (in miles)
Sample
1
2
3
4
5
6
7
date
(0.1)
(2.0)
(10.4)
(18.5)
(21.7)
(22.7)
(28.9)
Fall 1980
30
300
108
111
308
NA
122
Fall 1981
52
199
61
0
96
0
0
Fall 2009
0
4
359
3
NA
NA
NA
Spring
9
42
0
10
2
0
4
1981
Spring
0
0
5
2
41
<1
<1
2010
Ongoing Studies
Mayflies and Other Stoneflies Below Windy Gap
1983 to 2010 (number of taxa)
1983
2010
Mayfly Species
17
5
Stonefly Species
10
4
• Three other stonefly species appear to be missing from study area
• 70% of mayfly species previously reported in first two miles absent from spring 2010
samples
• Ephemerella sp. mayflies dominant at 3 of 7 sites in 2010
• Chironomidae and Simuliidae are now dominant groups at some sites.
Ongoing Studies
Sculpins (Cottus sp.)
• Important food item
• Need rocky, cobble
riffles
• Fertilized eggs guarded
by males until yolk sac
is absorbed
• Share habitat with
Pteronarcys
Ongoing Studies
Sculpins (Cottus sp.)
• 18 stations in September 2010
• One sculpin taken in reach between Windy Gap Dam and
confluence with Blue River
• Not found in Colorado River below Byers Canyon Bridge, yet
abundant in Beaver Creek
• Not found below Williams Fork Reservoir.
• Abundant and dominate numerically in two Fraser River sites
above Windy Gap
• Two stations in Willow Creek upstream of Willow Creek
Reservoir
• Colorado River below Shadow Mountain Dam.
Ongoing Studies
• Riffle areas immediately downstream of Windy Gap have
been altered
• Flow regime
• Water depletions
• Sedimentation
• Flushing flows
• Armored
• Conceptually, the river needs to be returned to a more
functional system in line with current hydrology.
Eastern Slope Impacts
Wildlife
• Loss of 810 acres of elk winter range, mule
deer winter range and concentration area, and
black bear foraging area
• General loss of habitat for other terrestrial
species, birds, amphibians
and reptiles
• Loss of 7 acres of bald
eagle winter range
Aquatic Resources
• Potential flatwater fishery at Chimney Hollow
Reservoir.
• Lower water levels in Carter Lake and
Horsetooth Reservoir would slightly reduce
available fish habitat.
Socioeconomics
• Property acquisition:
• Most eastern slope property already purchased
Stream Morphology and Floodplains
• Increased flows in Eastern Slope streams
below wastewater treatment plants could have
slight effect on channel morphology
• Flows in Eastern Slope streams would increase
slightly
Surface Water Hydrology
• Lower water levels in Carter Lake
• Flows in eastern slope streams would increase
slightly
• Lower water levels in Horsetooth (6” on
average)
Surface Water Quality
• Increased ammonia concentrations in St. Vrain
Creek, Big Dry Creek, Coal Creek as a result of
increased discharges from participant
wastewater treatment plants
• Nutrient increases (total phosphorus, nitrogen)
resulting in higher chlorophyll a concentrations
and decreased DO in Carter Lake and
Horsetooth
Vegetation
• Temporary impact to 123 acres of vegetation
during construction of dam and pipeline ROW
• Permanent loss of 788 acres
of vegetation to
Chimney Hollow inundation
NEPA Process
– Public Input from all stakeholders
• Includes State of Colorado
– DOW required to collaborate with NCWCD on Draft
Mitigation Plan (C.R.S. 37-60-122.2)
• Public Input Opportunity
– Wildlife Commission
– Public Meetings – Oct. 13 and Oct. 21
– Final Mitigation Plan = State’s Input to NEPA Process
• If Approved by:
– Colorado Wildlife Commission
– Colorado Water Conservation Board