Cyanobacteria bloom at Zylstra Lake in October 2018. San Juan County Land Bank, Contributed.
By Doug McCutchen, Preserve Steward, San Juan County Land Bank
This is the first in a series of articles describing the background of Zylstra Lake Preserve and the work that is going on to develop a long-term stewardship and management plan for the property. This article focuses on recreational access to the reservoir.
Zylstra Lake Preserve is easily the most complex project the San Juan County Land Bank has taken in its 30-year history.
The property is currently open to access, operating under an interim management plan.
Based on research, the Land Bank has elected to move slowly on the question of water access.
Sanctioning swimming access seems irresponsible and boating access is complicated by changes in water level and the potential of some simple contact-based health impacts.
In the short term, we are asking the community to refrain from water access and to be careful around the water.
Please keep your pets on a leash and do not allow them to swim or drink the water.
Fishermen are urged to be cautious when handling or consuming fish and are encouraged to wash their hands after fishing, especially when algal blooms are visually present.
Water Access
Water is the most important element for creating and sustaining life on the planet. Perhaps it is this innate dependence and deep biological connection with water that draws us to water for recreation. Whether scenic views, boating, or swimming, water is often at the center of where we seek our literal re-creation.
Water is also at the center of complexity at Zylstra Lake management as there is overlapping interest in recreational, agricultural and ecological use and connection to this valuable and scarce resource.
A small day-use area with swimming and boating access was part of the early vision for Zylstra. Although this level of use is a bit beyond the typical scope of the Land Bank’s “low-intensity recreation” mandate, there was consensus within the Land Bank Commission that the recreational need for this type of water access on the island is high.
The intention to move forward with this plan was elevated enough that the Land Bank began exploring a potential partnership with other agencies who might help manage this more intense use while we simultaneously began a series of environmental assessments of the property.
Algal Blooms
Our first inkling that there might be some management challenges came in the form of algal bloom reports, including the photograph taken by a local pilot and photographer Chris Teren.
Staff members began assembling research on algal blooms, especially cyanobacteria – a blue-green algae that matched observations. The following year, samples of the algae were sent for laboratory analysis when the blooms began in summer. The results confirmed the presence of potentially harmful types of cyanobacteria.
Around the same time, biologists working on an assessment of the property returned results of tests showing abnormally high levels of phosphorus, nitrogen, and related nutrient. Continue Reading