Integrated Aquatic Vegetation Management Plan

Black Lake has been actively managed for nuisance aquatic plants for over a decade. The District is now updating its long-term management plan to reflect current conditions and guide future actions.

Why Aquatic Vegetation Matters

Aquatic plants are a natural and important part of a healthy lake. Native vegetation provides habitat for fish and wildlife, stabilizes sediments, and supports the food web. Healthy plant communities also help maintain water clarity and overall ecological balance.

Not all aquatic plants function the same way. Some non-native or invasive species grow quickly and form dense stands that crowd out native plants, reducing habitat diversity and altering how the lake functions. When growth becomes excessive, it can also interfere with boating, swimming, and other recreational uses.

The goal of management is not to eliminate aquatic plants, but to maintain a balanced plant community that supports both ecological health and lake use.

What is an IAVMP?

An Integrated Aquatic Vegetation Management Plan (IAVMP) is a long-term strategy for managing aquatic plants in a lake. It begins with identifying plant species in the lake and their location, and based on that information setting management goals and evaluating a range of tools to achieve them.

These tools may include manual removal, habitat manipulation, biological controls, and approved aquatic herbicides. Rather than relying on a single method, an IAVMP combines approaches and adjusts them over time based on monitoring results and changing lake conditions.

Public input is an important part of this process. Lake users and residents experience the lake in different ways, and their input helps shape management goals, priorities, and acceptable approaches. Incorporating community perspectives ensures the plan reflects both ecological needs and how people use and value the lake.

Aquatic Vegetation in Black Lake

Black Lake has been actively managed to control non-native aquatic plants for over a decade. A previous IAVMP, developed in 2012 by Thurston County with support from the Washington Department of Ecology, identified key problem species including Eurasian watermilfoil, fragrant waterlily, and yellow flag iris.

Management has made real progress. Eurasian watermilfoil, once a major concern, has not been observed in recent surveys. But other challenges remain. Fragrant waterlily is still present in parts of the lake, and curlyleaf pondweed, a non-native species, has appeared.

Why Update the Plan Now?

Conditions in Black Lake have changed since the original plan was completed. Some species have been managed successfully, others have emerged, and the District has gained years of management experience.

A comprehensive lake-wide survey, included in the IAVMP update, will provide a current list of plant species and their locations to inform updated management goals and strategies. Community input will be part of this process, helping shape priorities and approaches. The updated plan is expected to be completed by December 2026.