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 dam has 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.
Explore more: Oldest dams in Washington · Tallest dams · High risk dams · Largest reservoirs
| Dam | Hazard | Condition | Height (ft) | Purpose | Year |
|---|---|---|---|---|---|
| Zintel Canyon Dam | High | Satisfactory | 125 | Flood Risk Reduction | 1992 |
| Sunnyside Mp 59.29 Reservoir | High | Fair | 44 | Irrigation | 2005 |
| Blair Reservoir Dam | High | Poor | 28 | Irrigation | 1937 |
| Kennewick Sewage Lagoon System | High | Satisfactory | 24 | Other | 1997 |
| Kennewick No 1 Aerated Wastewater Lagoon | High | Satisfactory | 24 | Other | 1975 |
| Kennewick No 2 Aerated Wastewater Lagoon | High | Fair | 24 | Other | 1975 |
| Paterson Ranch Reservoir | High | Fair | 23 | Irrigation | 2010 |
| Finley Ranch Reservoir | High | Satisfactory | 23 | Irrigation | 2013 |
| Gap Road Reservoir | High | Satisfactory | 17 | Irrigation | 2004 |
| Badger Mountain Irr Dist Reservoir Expan | High | Fair | 14 | Irrigation | 1977 |
| Baby Gap Ranch Reservoir | High | Satisfactory | 13 | Irrigation | 2015 |
| Lamb Weston Richland Lrad Lagoon | Significant | Satisfactory | 29 | Other | 2017 |
| Watts Bros Organic Dairy Lagoon 2 | Significant | Fair | 21 | Other | 2007 |
| Watts Bros Organic Dairy Lagoon 3 | Significant | Fair | 21 | Other | 2007 |
| Watts Bros Organic Dairy Lagoon 1 | Significant | Fair | 21 | Other | 2007 |
| Agreserves Plymouth Wastewater Storage Pond | Significant | Not assessed | 19 | Other | 2023 |
| Tree Top Prosser Lagoons 2 & 3 | Significant | Fair | 18 | Other | 1991 |
| Prosser Warehouse Treatment Lagoon | Significant | Satisfactory | 14 | Other | 2012 |
| Ste Michelle Canoe Ridge Evaporation Pond | Significant | Satisfactory | 14 | Other | 2012 |
| West Richland Sewage Lagoon North | Significant | Fair | 7 | Other | 1961 |
| Agrinw Spaw Pond | Significant | Not assessed | 0 | Irrigation | |
| Agrinw Feedlot Fresh Water Pond | Significant | Not assessed | 0 | Irrigation | |
| Coffin Sheep Dam No 3 | Low | Not assessed | 31 | Irrigation | 1938 |
| Roza Wasteway 6 Reregulation Reservoir | Low | Not assessed | 20 | Irrigation | 1988 |
| Ely Pump Storage Dam | Low | Not assessed | 15 | Irrigation | 1965 |
| K2h Farms Mcnary No 1 Reservoir | Low | Not assessed | 15 | Irrigation | 1980 |
| Sunheaven Farms Reservoir | Low | Not assessed | 13 | Irrigation | 1986 |
| Prosser Diversion Dam | Low | Not assessed | 9 | Irrigation | 1904 |