Agate Dam is a zoned earthfill embankment about 13 miles northeast of Medford, Oregon, on Dry Creek. The structure has a height of 86 feet and a crest length of 3,800 feet and contains 421,000 cubic yards of material. The reservoir behind the dam has a total capacity of 4,800 acre-feet (active 4,780 acre-feet).
Geology
Agate Dam is in a narrow valley with steep slide slopes. The left abutment juts out into the valley and at a height of 50 feet above the stream flattens off into a bench. Ice or glacial deposits, causing ice or glacial melt water to discharge, once blocked the stream channel over a bench a few hundred feet behind the left abutment. A channel developed which extends from this rock bench to a point in the present channel a few hundred feet downstream from the dam site. Bedrock at the lowest point of the old channel is about 15 feet above the reservoir flow line. Overburden at the flow line on the right abutment consisted of 28 feet of gravel with excess sand and silt. Boulders were hard, fresh andesite 2 to 3 feet in diameter. Much of the over burden between flow line and the valley flow was undoubtedly quite permeable.
General
Project
Rogue River Basin.
Dam Type
Zoned Earthfill
Location
11 miles NW of Medford
Longitude
-122.7723
Latitude
42.4155
Reservoir
Agate
National ID Number
OR00422
Watercourse
Dry Creek
Original Construction
1965-1966
Dimensions
Crest Elevation
1520.0 ft
Structural Height
86.0 ft
Hydraulic Height (Normal Operating Depth at Dam)
68.0 ft
Crest Length
3800.0 ft
Top of Active Conservation Pool (Elevation)
1510.0 ft
Top of Dead Storage Pool (Elevation)
1465.0 ft
Streambed at Dam Axis
1446.0 ft
Top of Inactive Conservation Pool (Elevation)
1467.0 ft
Spillway Crest Elevation
1514.0 ft
Hydraulics & Hydrology
Normal Water Surface Elevation
1467.0 ft
Spillway Type
Uncontrolled bathtub
Auxiliary Spillway
No
Total Water Storage at Elevation
4,780 ac-ft
Outlet Works Capacity at Elevation
78 cfs at 1514.0 ft
Drainage Area
13.0 sq mi
Hydrometeorological Report (HMR)
HMR 57
Spillway Capacity at Elevation
3500 cfs at 1514.0 ft
Contact
Owner
Title: Area Office Manager Organization: Columbia-Cascades Area Office Address: 1917 Marsh Road City: Yakima, WA 98901-2058 Fax: 509-454-5611 Phone: 509-575-5848-x202
Operator
Organization: Rogue River Valley Irrigation District Address: 3139 Merriman Road City: Medford, OR 97501-1277 Phone: 541-773-6127
More Information about the U.S. Bureau of Reclamation