Sullivan Lake Water Supply Project

View of Sullivan Lake (photo by:


  • Sullivan Dam and small dam downstream (Mill Pond Dam) constructed in 1911.

  • Small hydroelectric power plant (4MW) also constructed in 1911 and operated until 1956.

  • Pend Oreille PUD purchased the project in 1959, including water rights and water storage rights, and obtained a FERC License, but power was never generated by the District.

  • Project has been operated as directed in FERC License. FERC License is expiring and District plans to surrender the FERC License.


Current Sullivan Lake Operation

    click for larger image
  • Sullivan Lake fills and empties each year in accordance with Pacific Northwest Coordination Agreement and its existing FERC license.

  • The lake begins to fill each spring about April 1

  • To the extent possible, the lake maintains a constant full elevation of 2,588.6 for the months of June through September for summer recreation. The gates on the dam are opened October 1 to begin lowering the lake to provide room to catch spring run-off and provide downstream power benefits.

  • Lake is drained to elevation 2565.0 by about December 15 each year.

  • Minimum instream flow release of 10 cfs (of inflow, if lower) is maintained year-round. • US Forest Service has campgrounds and boat launches on Sullivan Lake. • Flows at the dams are monitored. Gates are adjusted and maintained. Five-year dam safety inspections are conducted as part of the FERC License.


Issues and Concerns

When Sullivan Dam FERC License was surrendered, therewas an opportunity to change project operations. Some of the issues of concern to agencies and the public include:

  1. Desire to improve fishery in Sullivan Creek. Sullivan Creek has been identified as potential bull trout recovery habitat;

  2. Desire to minimize water temperature increases during lake draining;

  3. Whitewater recreation enthusiasts desire flows in 200cfs range for optimum kayaking during lake draining;

  4. Desire to maintain lake full or near full in summer for recreation and for docks owned by local cabin owners;

  5. Desire to increase minimum instream flow releases;

  6. Desire to avoid rapid increases or decreases in dam discharge flows;

  7. Desire to control costs of new measures;

  8. Boundary Dam (downstream of Sullivan) is in FERC relicensing and Seattle City Light is interested in potential mitigation projects.

To address the issues, stakeholders participated in settlement discussions beginning in September 2009. Participants included:

 Pend Oreille PUD •  Seattle City Light
•  US Forest Service  Kalispel Tribe
•  Ecology •  WA Dept of Fish & Wildlife
 USFWS •  American Whitewater
•  The Lands Council •  Members of the public

Settlement was reached in February 2010 and was submitted to FERC and US Forest Service for environmental review and approval. WDOE 401 application


Operational Changes

  • Instream flow releases increased from 10 cfs to 60 cfs in June, to 30 cfs in July and August.

  • Lake draining started sooner (day after Labor Day instead of October 1).

  • Lake draining target elevation increase from 2565.0 to 2570.0 (5 feet less drawdown).

  • Water temperatures and flows monitored and releases adjusted to avoid downstream temperatures over 16C.

  • Cold water release pipe will be constructed to allow dam discharges to come from deep in the lake, with cooler water.

  • Mill Pond dam will be decommissioned and removed.

  • Flow rate changes will be controlled to meet agreed upon flow ramping rates.

As a result of revising the operations at Sullivan Lake, most of the identified issues are addressed. Additional flows are released from current situation as follows:

  • June-50 cfs average increase-3,000 ac-ft additional release in June

  • July and August-20 cfs average increase-1200 ac-ft additional release per month (2,400 total)

  • September-previously only 10 cfs released. Now expect average year releases to be 150 cfs all month –about 9,000 ac-ft

  • Total new releases June 1-Sept. 30 = 14,400 ac-ft