Crystal Lake Nutrient TMDL Five Year Review

This report is a review of progress toward meeting the load reductions identified in the Crystal Lake Nutrient TMDL (Wenck 2008). It includes an assessment of actions that have been implemented and the water quality trends that have been observed. Finally, this report describes the actions planned for the next 5 years of the implementation plan and sets forth how progress toward the TMDL will be measured. Crystal Lake was formally designated an Impaired Water for excess nutrients in 2002. A TMDL and Implementation Plan were approved in 2008 and 2009, respectively. The TMDL determined that a phosphorus load reduction of 69% is necessary to ensure the lake meets water quality standards for nutrients. The TMDL requires a 90% reduction in load from internal sources, and a 59% reduction from the watershed. The Implementation Plan identified priority actions and strategies for the first five years of implementation. Some of these have been completed or are in planning. Other actions such as implementing load reduction and infiltration strategies as opportunities arise are ongoing. Annual monitoring of lake water quality on Crystal Lake has been conducted intermittently over the past 20 years, primarily through the Metropolitan Council's Citizen Assisted Monitoring Program (CAMP). In preparation for this Five Year Review, more intensive monitoring, sediment core sampling, and aquatic vegetation monitoring were completed.