Ocean Shores plan targets harmful algal blooms; stormwater rate study shows several funding paths

Consultants presented a freshwater harmful-algae (cyanobacteria) management plan for the City of Ocean Shores and a companion stormwater utility rate study that models how the city could pay for the plan.

Katie Rodriguez, a scientist with Herrera Environmental Consultants, said the plan divides the city’s canals and lakes into nine management units and recommends continuing monitoring, expanding communications, and a mix of in-water controls and watershed actions. "We think that this is coming in from ancient buried peatlands beneath the city of Ocean Shores," Rodriguez said, describing consultants' conclusion that groundwater phosphorus — naturally leaching from buried peatlands and connected to surface waters because of permeable soils — is the largest nutrient source driving blooms.

The plan’s nut graf: consultants recommended a combined program of regular bloom surveillance and water-quality monitoring; clearer public communications and reporting; targeted in-water treatments (mixing/circulation, oxygenation, phosphorus inactivation such as alum, and limited algaecide use); and continued watershed work (sewer and stormwater improvements, reduced fertilizer use, shoreline plantings). The plan presents three “levels of service” with different mixes of actions and costs, and an adaptive-management approach that allows pilot testing of technologies.

Major findings and policy goals

Consultants reported 2024 monitoring results showing the waterways are largely eutrophic to hyper‑eutrophic, with higher cyanobacteria and at least one exceedance of Washington State guidelines for microcystin. Rodriguez summarized systemwide objectives: reduce the number of years with blooms to fewer than two in each 10‑year period (based on…