The Yelm Hydroelectric Project was commissioned in the 1920s by the City of Centralia at a cost of $995,000 and generated approximately 4 MW of power. Over the decades, the project was expanded and upgraded, now generating over 12 MW and providing 25-30% of the city's electricity, with additional power supplied by BPA. The project diverts water from the Nisqually River via a diversion dam and 9 mile canal to the powerhouse containing three turbine generators.

1. Centralia City Light
Yelm Hydroelectric Project
FERC # 10703

2. Who Are We

3. The City of Centralia commissioned the
construction of the Yelm Hydroelectric
Project in the mid 1920s at a cost of
approximately $995,000.00 through a city
backed bond. The bond was repaid within
10 years.
The project commenced commercial
operations in 1930 generating
approximately 4 Mw to the City of
Centralia.
History of the Yelm
Hydroelectric Project

4. The Orginal project consisted of:
Power house consisted of two 1.8 Mw
hydro turbine generators
9.1 miles of canal
26.2 miles of transmission line
Part of City of Centralia’s agreement with land
owners were to construct and maintain
bridges to allow land owners to access their
property on the other side of the canal.
History of the Yelm
Hydroelectric Project

5. To supplement the city’s electrical
resources, the city entered into a
purchase agreement with BPA in 1941.
Today the Yelm Hydroelectric Project
generates 12+ Mw and provides to the
City of Centralia 25–30 % of its electricity.
BPA still supplements the additional
power requirements for the city.
History of the Yelm
Hydroelectric Project

6. In 1955 the city extended the power
house to install a third hydro
generator unit rated at 5 Mw.
To support the additional generation,
the canal flow was increased from 350
cfs to todays 800cfs.
History of the Yelm
Hydroelectric Project

7. In 1975 the original 1.8 Mw
generators were rewound to 3.0 Mw
increase the Yelm Hydro generation
output to 11 Mw.
Today the Yelm Hydroelectric Project
generates 12+ Mw
History of the Yelm
Hydroelectric Project

8. In 1975, the original wooden box
flume was replaced with a concrete
box flume to handle a flow of 1100
cfs.
History of the Yelm
Hydroelectric Project

9. In 1997 the Yelm Hydroelectric Project
came under FERC jurisdiction and was
awarded the project number of
10703.
History of the Yelm
Hydroelectric Project

10. In 2010-2011 the transmission substation
located at the Yelm Hydroelectric Project
was modernized and is rated at 69 Kv.
The power generated is transmitted 26.2
miles along the city’s transmission line to
the city’s B-Street substation.
History of the Yelm
Hydroelectric Project

11. Diversion Dam Facility

12. Diversion Dam Facility
The diversion dam
is a 4 foot concrete
barrier used to
direct water into
the Centralia
Power Canal.

13. Fish Ladder

14. Fish Screen Structure
The fish screen
structure prevent
fish from entering
the power canal.
It diverts the fish
back to the river
through a fish
return tube.

17. Wild Life Habitat
As part of the FERC licensing requirements and after the
flood of 1996 the City of Centralia was requested to
establish a wild life habitat area.

18. Bridges
The City of Centralia is
responsible for the
construction and
maintenance of private
owned bridges.
Currently the City
maintains 9 brides that
cross our canal.

20. Centralia Power Canal
The power canal is 9.1 miles and conveys up to
800 cfs to the Yelm Hydro Power House

23. Canal Embankment

24. Yelm Hydroelectric Project

26. Forebay Valve House

27. Power House

28. Hydro Turbines and Generators

30. Nisqually Park
The city maintains
a path way from
our project to the
Nisqually River for
fishing, rafting,
and boating

31. McKenna Park

34. Notice to Rafters

35. Hazards

36. Concrete Flume

39. What Do We Have to Offer
• Boat Ramps
• Picnic Areas
• Park / Play Area for Children
• Dog Area
• Bird Watching
• Education - Tours
• Wild Life

40. Boat Ramps

41. Picnic Area

42. Park / Play Area

43. Dog Area

44. Bird Watching

45. Education - Tours

46. Wild Life

51. QUESTIONS