Haystack Dam

Overview

Haystack Dam is a zoned earthfill offstream storage facility located about 10 miles south of Madras, Oregon. Most of the stored water in the reservoir is diverted from the North Unit Main Canal which receives its water from Wickiup Reservoir. Releases from Haystack Reservoir flow in a feeder canal back to the North Unit Main Canal for use in the service area. The feeder canal also acts as a spillway.

Because of the distance from Wickiup Reservoir to the lands of the North Unit, the regulatory storage provided by the 5,600 acre-foot Haystack Reservoir is required. The dam is an earthfill structure, 105 feet high at its crest with a width of 25 feet and length of 1,200 feet, containing 535,000 cubic yards of material.

Geology

Bedrock at the damsite was mapped as the John Day Formation.  This mapping indicates the dam is a member of the formation consisting of rhyolite, ash-flow sheets, bedded, welded and lapilli tuffs with interbedded tuffaceous sedimentary rock.  The implied source area for the volcanic material is Juniper Butte; a rhyolite dome with associated flows located two miles southwest of the dam.  Robinson infers a north 75-degree trending fault one half mile south of Haystack Dam.  The fault displaces John Day Formation and the underlying Clarno Formation but does not cut the younger Madras Formation surrounding the butte and overlapping the older formation.  Surficial deposits on the valley floor along the axis of the dam ranged from 0 to 24 feet in depth.  These deposits were alluviums, consisting of silty sand, coarse sand, clayey sand and gravel.  Toward the left abutment the overburden deposits were alluvium and talus and near the base of the slope about 30 feet thick.  Bedrock under the surficial deposits in the valley consisted of rhyolite and tuff and was exposed at the surface near the top of both abutments.


General
RegionFacilities in Pacific Northwest | Pacific Northwest Home Page
StateOregon
CountyCook, Deschutes, Jefferson
ProjectDeschutes
Dam TypeZoned Earthfill
ReservoirHaystack
WatercourseOff stream - unnamed internittent creek
Location
Longitude-121.15525
Latitude44.4991378
Original Construction1956-1957
Modified Construction
National ID NumberOR00287
Hydrologic Unit Code

Dimensions
Structural Height105 ft
Hydraulic Height (Normal Operating Depth at Dam)73.5 ft
Top Parapet (Elevation)
Spillway Crest Elevation2848.8 ft
Crest Elevation2853.0 ft
Crest Length1200.0 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)2842.0 ft
Top of Inactive Conservation Pool (Elevation)
Top of Dead Storage Pool (Elevation)

Hydraulics & Hydrology
Total Water Storage at Elevation 5,635 ac-ft
Maximum Water Surface Elevation
Normal Water Surface Elevation2842.0 ft
Spillway Type
Auxiliary SpillwayNo
Spillway Capacity at Elevation 800 cfs
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation 460 cfs
Diversion Capacity at Elevation
Drainage Area11.0 sq mi
Hydrometeorological Report (HMR)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
OrganizationNorth Unit Irrigation District
Address2024 NW Beach St
CityMadras, OR 97741-9484
Phone (Office)541 475-3625


Last updated: Feb 25, 2009