Keene Creek Dam

Overview

Keene Creek Dam is a 78-foot-high, 558-foot-long zoned earthfill embankment dam located 16 miles east of Ashland, Oregon, on Keene Creek. Behind the dam is the Keene Creek Reservoir with a total capacity of 390 acre-feet (active 260 acre-feet), which has sufficient water for the weekly cycle of powerplant operation for peaking power production of Green Springs Powerplant. The purpose of Keene Creek Dam is to reregulate releases from Howard Prairie and Hyatt Reservoirs to provide forebay pondage for Green Springs Powerplant.

Geology

The Keene Creek Dam and Reservoir are located in the Western Cascade geotectonic province of the Cascade Range on the West Side of that volcanic mountain belt.  The project is in the easternmost part of the Western Cascades, which is characterized lithologically by slightly deformed and partly altered andesitic and bastalic lava flows and pyroclastic rocks of mid Tertiary age and physiographically by a deeply-eroded mature.  Topography with deep canyons and fairly strong development of cuesta-type ridges expressive of the easterly dip of 10 to 20 degrees of the volcanic strata.  This volcanic sequence has a thickness of 3,000 to 5,000 feet.  Structurally it is complicated by intrusives and faulting and folding as well as the eastward tilting.  Within one mile west of the project High Cascade geotectonic province forms the highest part of the Cascade Range.  It is characterized by late Tertiary to Holocene volcanism, which is represented locally by the lower slopes of the Chinquapin Mountain.  This volcano of probable Pleistocene age has a peak elevation of 6106 feet, is 2.5 miles northwest of the dam and lies several miles west of the main chain of volcanoes.  Crater Lake which erupted about 6,000 years ago is 60 miles to the north.  The closest Holocene volcanism is believed to have been at Mount Macloughlin, about 22 miles to the north.  Pleistocene glaciation in the Cascade Range did not extend south of Mount Macloughlin, but the effects of wetter climate appears to be expressed in the deep weathering alteration of the volcanic bedrock, steep-sided valleys and landslides in the Western Cascades.


General
RegionFacilities in Pacific Northwest | Pacific Northwest Home Page
StateOregon
CountyJackson
ProjectRogue River Basin
Dam TypeZoned Earthfill
ReservoirKeene Creek
WatercourseKeene Creek
Location
Longitude-122.478911
Latitude42.129277
Original Construction1957-1959
Modified ConstructionOR00591
National ID Number
Hydrologic Unit Code

Dimensions
Structural Height78.0 ft
Hydraulic Height (Normal Operating Depth at Dam)67.0 ft
Top Parapet (Elevation)
Spillway Crest Elevation4407.0 ft
Crest Elevation4412.5 ft
Crest Length558.0 ft
Crest Width
Base Width
Volume of Dam Construction Materials
Streambed at Dam Axis
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)4403.5 ft
Top of Inactive Conservation Pool (Elevation)4378.0 ft
Top of Dead Storage Pool (Elevation)4371.5 ft

Hydraulics & Hydrology
Total Water Storage at Elevation 260 ac-ft
Maximum Water Surface Elevation
Normal Water Surface Elevation4403.5 ft
Spillway Type Ungated
Auxiliary SpillwayNo
Spillway Capacity at Elevation2,650 cfs at 4407.0 ft
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation190.0 cfs outlet to Green Springs Powerplant
Diversion Capacity at Elevation
Drainage Area
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report

Contact Information
Owner
TitleArea Office Manager
OrganizationColumbia-Cascades Area Office
Address1917 Marsh Road
CityYakima, WA 98901-2058
Phone (Fax)509 454-5611
Phone (Office)509 575-5848 x202
Operator
OrganizationTalent Irrigation District
AddressPO Box 467
CityTalent, OR 97540-0467
Phone (Office)541 535-1529


Last updated: Apr 30, 2009