Guidebook for Controlling Harmful Algal Blooms in the Tualatin River Watershed

The Joint Water Commission’s (JWC) TREE Grant project, titled “Reducing Threats to Drinking Water from Surface Water Impoundments”, addresses water quality concerns in the upper-Tualatin River watershed by identifying surface water impoundments in the JWC’s drinking water source area (DWSA) (Figure 1) that have the potential to develop harmful algal blooms (HABs). HABs can affect human health, aquatic ecosystems, the local economy, and surface water quality. Surface water quality in the upper-Tualatin River watershed is important to protect as it affects drinking water quality. Impaired surface water quality could lead to increased costs associated with surface water treatment and monitoring. 

Additionally, if the cyanotoxin concentration in HABs are high enough it could lead to “Do Not Drink” advisories for at risk populations, such as children, the elderly, people who are pregnant, pets, and immunocompromised groups.