Dams in Benton County, Washington

28Total Dams
11High Hazard
11Significant

Dam Safety in Benton County, Washington

Benton County has 28 dams tracked in the National Inventory of Dams. Of these, 11 are classified as high hazard — meaning failure would probably cause loss of human life. Another 11 carry a significant hazard classification. Currently, 1 dams have a condition assessment of poor or unsatisfactory.

The average dam in Benton County is 37 years old. The most common purpose is irrigation. The tallest dam is Zintel Canyon Dam at 125 ft.

DamHazardConditionHeight (ft)PurposeYear
Zintel Canyon DamHighSatisfactory125Flood Risk Reduction1992
Sunnyside Mp 59.29 ReservoirHighFair44Irrigation2005
Blair Reservoir DamHighPoor28Irrigation1937
Kennewick Sewage Lagoon SystemHighSatisfactory24Other1997
Kennewick No 1 Aerated Wastewater LagoonHighSatisfactory24Other1975
Kennewick No 2 Aerated Wastewater LagoonHighFair24Other1975
Paterson Ranch ReservoirHighFair23Irrigation2010
Finley Ranch ReservoirHighSatisfactory23Irrigation2013
Gap Road ReservoirHighSatisfactory17Irrigation2004
Badger Mountain Irr Dist Reservoir ExpanHighFair14Irrigation1977
Baby Gap Ranch ReservoirHighSatisfactory13Irrigation2015
Lamb Weston Richland Lrad LagoonSignificantSatisfactory29Other2017
Watts Bros Organic Dairy Lagoon 2SignificantFair21Other2007
Watts Bros Organic Dairy Lagoon 3SignificantFair21Other2007
Watts Bros Organic Dairy Lagoon 1SignificantFair21Other2007
Agreserves Plymouth Wastewater Storage PondSignificant19Other2023
Tree Top Prosser Lagoons 2 & 3SignificantFair18Other1991
Prosser Warehouse Treatment LagoonSignificantSatisfactory14Other2012
Ste Michelle Canoe Ridge Evaporation PondSignificantSatisfactory14Other2012
West Richland Sewage Lagoon NorthSignificantFair7Other1961
Agrinw Spaw PondSignificant0Irrigation
Agrinw Feedlot Fresh Water PondSignificant0Irrigation
Coffin Sheep Dam No 3Low31Irrigation1938
Roza Wasteway 6 Reregulation ReservoirLow20Irrigation1988
Ely Pump Storage DamLow15Irrigation1965
K2h Farms Mcnary No 1 ReservoirLow15Irrigation1980
Sunheaven Farms ReservoirLow13Irrigation1986
Prosser Diversion DamLowNot Available9Irrigation1904