Willow Creek Dam
Encyclopedia
Willow Creek Dam is a dam
in Morrow County
of the U.S. state
of Oregon
, located just east of Heppner
's city limits. It is the first major dam constructed of roller-compacted concrete
.
The dam's drainage basin is 96 square miles (248.6 km²)
of arid rolling hills in the lower basin but with headwaters in the northern Umatilla National Forest
.
The dam's original purpose was primarily to store water for flood control, but also to serve recreation, fish and wildlife, and irrigation uses. The dam impounds Willow Creek
to create Willow Creek Lake.
The lake level can be a maximum of 2113.5 feet (644.2 m) elevation and a minimum of 2063 feet (628.8 m) for a total usable storage capacity of 9765 acre.ft.
from thunderstorms which killed approximately one quarter of the residents of Heppner.
A flood control study was completed in 1962 at a total cost of $219. In 1965, a flood control project was authorized by U.S. Congress.
In 1979, the purpose of a dam project was changed to defer irrigation development for the future and eliminate water supply and water quality control.
Construction feasibility tests in 1972 placed a few layers of roller-compacted concrete. A 1:36 model (one inch equals three feet) was built and studied to determine downstream flooding and pool siltation characteristics as affected by the dam's spillway.
The dam was constructed by the Army Corps of Engineers between November 1981 and February 1983.
Construction completed nearly on schedule, despite the workers initially being unfamiliar with the materials, processing, and techniques. It came in less than its budget of $50 million at $35 million.
The dam's construction validated economic and construction speed benefits where 330000 cubic metres (431,623.7 cu yd) of concrete were finished in less than 5 months at about $17 per cubic meter ($13/yd3), which includes additional efforts to correct defects.
However, as soon as the lake began filling, significant leakage was evident through the seams of the layers of concrete. The lake was drained and a $2 million remedial included injecting grout through bores drilled from top to bottom. The initial rate of leakage was 33 m3/s. After remediation, the leakage was less than 11 m3/s. Concern over the dam's safety has continued, especially as Heppner had already suffered a dam collapse and fatal flooding with about 250 deaths in 1903.
Within a few years of construction, problems were noted with stratification of the water and anoxic decomposition producing hydrogen sulfide
. Concerns were expressed that this could in turn give rise to sulfuric acid leading to concrete damage. Controversy continued for some years and the handling of the problem itself has been criticized. In 2004 an aeration plant was installed to address the root cause, as had been called for 18 years earlier. Subsequent controversy surrounded the politics of a small town being used as an experiment for new construction technology.
SolarBee devices to circulate the water were installed in 2009.
The dam won an American Society of Civil Engineers
(ASCE) award in 1985.
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
in Morrow County
Morrow County, Oregon
Morrow County is a county located in the U.S. state of Oregon, on the south side of the Columbia River. It is included in the 8 county definition of Eastern Oregon. The county is named for one of its first white settlers, Jackson L. Morrow, who was a member of the state legislature when the county...
of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, located just east of Heppner
Heppner, Oregon
The city of Heppner is the county seat of Morrow County, Oregon, United States. It was originally called Standsbury Flat for George W. Standsbury, one of the first white settlers in the area. It was later renamed to honor Henry Heppner, a Jewish pioneer who opened the first general store there in...
's city limits. It is the first major dam constructed of roller-compacted concrete
Roller-compacted concrete
Roller-compacted concrete or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. RCC is a mix of cement/fly ash, water, sand, aggregate...
.
The dam's drainage basin is 96 square miles (248.6 km²)
of arid rolling hills in the lower basin but with headwaters in the northern Umatilla National Forest
Umatilla National Forest
The Umatilla National Forest, in the Blue Mountains of northeast Oregon and southeast Washington, covers an area of 1.4 million acres . In descending order of land area the forest is located in parts of Umatilla, Grant, Columbia, Morrow, Wallowa, Union, Garfield, Asotin, Wheeler, and Walla Walla...
.
The dam's original purpose was primarily to store water for flood control, but also to serve recreation, fish and wildlife, and irrigation uses. The dam impounds Willow Creek
Willow Creek (Columbia River)
Willow Creek is a long tributary of the Columbia River, located in the U.S. state of Oregon. It drains of Morrow and Gilliam counties. Arising in the Blue Mountains, it flows generally northwest to its confluence with the Columbia River upstream of Arlington.-Course:Willow Creek's headwaters are...
to create Willow Creek Lake.
The lake level can be a maximum of 2113.5 feet (644.2 m) elevation and a minimum of 2063 feet (628.8 m) for a total usable storage capacity of 9765 acre.ft.
History
The peak discharge of the creek was 36000 cuft/s in 1903 as a result of a flash floodHeppner Flood of 1903
The Heppner Flood of 1903 was a major flash flood along Willow Creek responsible for destroying a large portion of Heppner, Oregon, United States, on June 14, 1903...
from thunderstorms which killed approximately one quarter of the residents of Heppner.
A flood control study was completed in 1962 at a total cost of $219. In 1965, a flood control project was authorized by U.S. Congress.
In 1979, the purpose of a dam project was changed to defer irrigation development for the future and eliminate water supply and water quality control.
Construction feasibility tests in 1972 placed a few layers of roller-compacted concrete. A 1:36 model (one inch equals three feet) was built and studied to determine downstream flooding and pool siltation characteristics as affected by the dam's spillway.
Construction completed nearly on schedule, despite the workers initially being unfamiliar with the materials, processing, and techniques. It came in less than its budget of $50 million at $35 million.
The dam's construction validated economic and construction speed benefits where 330000 cubic metres (431,623.7 cu yd) of concrete were finished in less than 5 months at about $17 per cubic meter ($13/yd3), which includes additional efforts to correct defects.
However, as soon as the lake began filling, significant leakage was evident through the seams of the layers of concrete. The lake was drained and a $2 million remedial included injecting grout through bores drilled from top to bottom. The initial rate of leakage was 33 m3/s. After remediation, the leakage was less than 11 m3/s. Concern over the dam's safety has continued, especially as Heppner had already suffered a dam collapse and fatal flooding with about 250 deaths in 1903.
Within a few years of construction, problems were noted with stratification of the water and anoxic decomposition producing hydrogen sulfide
Hydrogen sulfide
Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...
. Concerns were expressed that this could in turn give rise to sulfuric acid leading to concrete damage. Controversy continued for some years and the handling of the problem itself has been criticized. In 2004 an aeration plant was installed to address the root cause, as had been called for 18 years earlier. Subsequent controversy surrounded the politics of a small town being used as an experiment for new construction technology.
SolarBee devices to circulate the water were installed in 2009.
The dam won an American Society of Civil Engineers
American Society of Civil Engineers
The American Society of Civil Engineers is a professional body founded in 1852 to represent members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE's vision is to have engineers positioned as global leaders who strive toward...
(ASCE) award in 1985.
External links
- Photo gallery of Heppner flood US Army Corps of Engineers, 1903 and 1971