The City of Snohomish is moving forward with a proposal to establish the Blackman Lake watershed as a phosphorous-sensitive zone, which would impose new requirements on local development projects. This initiative is crucial in addressing the escalating problem of cyanobacteria blooms, which are fueled by excess phosphorous and pose significant health risks to both humans and wildlife. Studies indicate that the lakebed is a major source of phosphorous, necessitating urgent intervention. To combat this issue, the city consultant has advised that all new developments must incorporate phosphorous treatment controls. Moreover, the city is considering immediate algae treatments while evaluating future non-chemical solutions like modern underwater oxygen pumps.

The City Council previously approved alum treatments, designed to lock phosphorous at the lake's bottom, as part of the broader strategy to manage toxic algae. The draft plan outlining these measures is available for public access on the Snohomish city website. Community engagement is encouraged as the city seeks to address this environmental challenge effectively.