WSP12360

• File Number: 8040.960
• Description: Section D General Studies - Dams
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 4/11/2003
• Author: Denver Water
• Title: Williams Fork Hydroelectric Project - FERC Number 2204 - Scoping Document 1 - For the Relicensing of the Williams Fork Reservoir Hydroelectric Project
• Water Supply Pro - Doc Type: Report/Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

001909

Scoping Document I
Williams Fork Hydroelectric Project
FERC Project No. 2204

eXisting Project that would increase generation capacity at the Project. An
increase in generation capacity would allow Denver Water to seek an exemption
for the Project. The total combined capacity of the Project with the addition of
the smaller unit would meet the "5 MW or less" criteria for a small hydroelectric
power project exemption.

The proposed small unit will have a nominal generation capacity between 500
KW (0.5 MW) and 1.8 MW. The unit will be designed to capture lower flows
(under 70 cfs) and excess higher flows (greater than 220 cfs at rated head of 192
ft. and greater than 260 cfs at 160 ft. of head) released from the dam that are
currently not captured by the existing 3. I 5 MW unit. Once the hydrologic data is
furnished to a hydro turbine manufacturer, the exact turbine and generator size
will be defined. Flow and head for the small unit would be derived from the
existing 66-inch diameter penstock. A connection to the penstock would be made
on a section of piping after it exits the downstream face of the dam and before the
existing turbine inlet. This unit would be located adjacent to the existing
powerhouse where the river outlet works currently resides and would discharge
into the same tailrace as the existing hydroelectric turbine.

The addition of the new small unit is expected to have minimal, if any, impact on
the existing Project.

Williams Fork Reservoir would continue to be used as a municipal water supply
reservoir. Water supply operations at the reservoir would not be changed to
accoJlllllodate power production.

4.1.4 Environmental Measures

Past environmental measures in the FERC Project area have primarily focused on
recreation enhancements. Denver Water has established two fonnal campgrounds
with 47 automobile accessible campsites, two boat-launch sites, several picnic
areas, fishing access, parking, vault toilets, fire rings, and trash receptacles at the
reservoir. Dispersed primitive style camping also occurs around the reservoir that
is not either managed or controlled.

As part of the application. Denver Water proposes to address the following issues
as environmental enhancements and environmental measures.

. Study ramping flows to improve conditions for the downstream fishery.

. Collect and study recreational use data to detennine if changes to the existing
recreation management plan are necessary.

· Reconfigure the camping area at the inlet campground due to erosion and
provide stream bank protection to insure that the area is protected from further
erosion in the future.

]4