The Black Creek Hydroelectric Project is located on Black Creek, a tributary of the North Fork Snoqualmie River in the central portion of western Washington in King County. The project area lies near the foothills of the Cascade Mountains, approximately 30 miles east of Seattle and 5 miles northeast of the city of North Bend. Interstate 90 passes through North Bend south of the Project. County and private roads provide access to the project area.
|Project Name||Black Creek|
|LIHI Certificate Number||6|
|LIHI Effective and
|April 10, 2013
April 10, 2018
|Owner||Hydro Energy Development Corporation|
|Location||Located on Black Creek, a high gradient tributary of the South Fork of the Snoqualmie River in Washington.|
|Installed Capacity||3.7 MW|
|Average Annual Generation||10 GWH|
The topography in the vicinity of the Project is primarily mountainous. The forested area surrounding the Black Creek Project area is owed by Hancock Forest Management and is managed for timber harvesting. The area is in various stages of regeneration from clear cut logging activities.
Black Creek flows northwest into the North Fork of the Snoqualmie River from steeply rolling uplands. The estimated average annual flow in Black Creek is approximately 25 cfs. Flows are naturally very low during late summer and early fall. Black Creek drains a relatively flat upland basin at an elevation of approximately 2,400 feet. Then it drops about 1,600 feet in less than 0.75 miles before entering the North Fork Snoqualmie River. The north Fork Snoqualmie River heads near the crest of the Cascade Mountains and flows westerly to the junction of the Snoqualmie River near the town of Snoqualmie. Snoqualmie Falls, 0.5 miles downstream of the town, has a vertical drop of 268 feet and is a popular tourist attraction.
Black Creek Hydroelectric Project received a License from the Federal Energy Regulatory Commission in July 1988. Construction was completed and the Project was ready for commercial operation in May 1994. The Project consists of a diversion and intake structure, a 6310-foot-long pipeline/penstock, a powerhouse containing a single 3,700 kW generating unit, and a tailrace (see Attachment B). The Project is operated on a run-of-river basis, generating electrical energy from available stream flow. The Project operates only when flows in Black Creek exceed the minimum instream flow requirement of 5.4 cfs plus the minimum plant requirement of 4 cfs. The maximum turbine flow is 40 cfs. Normal operation of the Project is automatically controlled and includes emergency shutdown capability. The Project is generally in operation eight to nine months of the year with shutdown in late summer and early fall months due to low stream flow. Minimum flows are provided in the 0.97 mile bypass reach, downstream of the diversion site. The bypass reach is described as a very rugged and steep gradient natural stream. Several falls of 30 feet or more are located in this stretch.
The diversion and intake structure are located just upstream of Hancock Road No. 32852. The concrete diversion weir is eight-feet high and 46-feet in length with the crest elevation at 2300.94 feet, the elevation of the normal water surface. The diversion dam was designed to provide for the automatic release of minimum flows, and to pass the natural bedload material to maintain the existing channel structure downstream of the diversion dam. The intake is a concrete box intake with a slide gate and is located on the left bank of the creek. The diversion/intake site includes a trashrack, sluice gate, fish screens, a fish bypass slot, an automatic trashrack cleaning machine, and an intake control house. Hancock Road 32852 provides access to the diversion area. A new spur road, approximately 60 feet in length, off of Hancock Road 32852 was constructed to provide access to the diversion site.
The penstock includes 2440 feet of 36-inch-diameter and 3690 feet of 30-inch-diameter spirally welded steel pipe. The penstock is buried its entire length except for where it crosses Black Creek just downstream of the diversion site. At this location the penstock crosses Black Creek adjacent to the bridge on the downstream side, approximately 6 feet above the normal water level. A portion of the penstock is buried adjacent to Hancock Road 32852 and the penstock traverses under Hancock Roads 32852 and 32800 at several locations. Since construction of the Project, the penstock route has been successfully rehabilitated and re-vegetated (refer to item D of the questionnaire).
A 42 by 31 foot powerhouse is located on a terrace in the hillside, above the North Fork Snoqualmie River. The powerhouse contains a 3,700 – kW generator connected to a 5,190 – horsepower twin jet horizontal Pelton turbine located at centerline elevation 972.16. The powerhouse tailrace consists of a small 200 foot long open channel that empties into an unnamed creek. A switchyard is located near the powerhouse. The switchyard is equipped with an oil containing berm and oil collection facility; the yard is fenced and locked at all times. Access to the powerhouse area is via Hancock Roads 32800 and 32950; a new road, approximately 1,200 feet in length, was constructed off of Hancock Road 32950 to provide access to the powerhouse site.
A 34.5 kV transmission line runs underground along existing roads for 10.3 miles to where it is connected to a distribution system near the Salish Lodge at Snoqualmie Falls.
Numerous environmental plans were prepared, approved, and implemented as required under the FERC License for the project (Attachment C). Mr. Klinkenberg from the Portland office of the Federal Energy Regulatory Commission (FERC) conducted an Environmental and Public Use Inspection 1997 and concluded that the Licensee is in compliance with all license requirements pertaining to environmental matters. This report is included as Attachment D. Mr. Chin Lee from FERC Portland office had conducted on-site inspections of the site since 1998 (see agency contacts). His inspection reports show that the Licensee is in compliance with the requirements of the License. These reports are non-public, so they are not attached with this questionnaire. On September 17, 2012 Norman J. Weseloh, Jr and Ms. Elisabeth Matt from the FERC Division of Dam Safety and Inspections, Portland Regional Office inspected the project and stated the following, “the project structures were in good condition and very well maintained. No conditions were observed that would adversely affect the immediate safety and permanence of the structures. No problems, discrepancies or matters of noncompliance were observed.”
The clean energy benefit of the Black Creek facility is the generation of approximately 10 million kWh of electricity per year. Using current U.S. EPA data for typical household electricity demand, that annual generation is enough to supply electricity to 870 homes. In addition to those energy benefits, the Black Creek facility provides ecological benefits to local rivers by maintaining minimum flows to protect fish habitat downstream of its diversion points and screening out any resident fish that may move past the diversion dam. The applicable state and federal resource management agencies have confirmed during the recertification review that the Black Creek facility continues to be in compliance with all regulatory requirements.
August 21, 2014: Black Creek Project recertified for a third 5-year term, effective April 10, 2013 and expiring April 10, 2018.
May 9, 2013: Black Creek Hydro, Inc. submitted an application for re-certification of the Black Creek Project.
October 23, 2008: Black Creek Project re-certified for a second 5-year term, effective April 10, 2008 and expiring April 10, 2013.
July 21, 2003: Black Creek Project is certified as low impact for a 5-year term, effective April 10, 2003 and expiring April 20, 2008.
June 9, 2003: Public comment period on application closed.
April 10, 2003: Black Creek Project application posted to website; comment period opened.