5.8.5 Other

This Plan identified the need to consider an internal load management project in Dutch Lake, but that project was not included in the 2007-2016 prioritized CIP. The Board may consider such a project during the time frame of this Plan if funds are available.

ProjectDutch Lake Internal Load Management Project
DescriptionDesign and implementation of strategies to reduce internal phosphorus loading, including: feasibility study; aquatic vegetation survey update and management plan; fishery survey update and management plan; biomanipulation strategies that may include aquatic vegetation management, zooplankton community and fishery manipulation, and chemical treatment
Need

The modeled watershed phosphorus wash-off load to Dutch Lake is not sufficient to explain the in-lake concentration of total phosphorus that exceeds the lake’s total phosphorus goal. An “unknown load” to Dutch Lake is attributed to internal loading, and is likely a combination of bottom sediments, aquatic vegetation, and model accuracy. A watershed and lake diagnostic / feasibility study will be required to confirm the internal and external phosphorous loading to Dutch Lake, as well as the necessary load reductions. In particular, the “unknown load” must be identified as either an external or internal load before specific strategies can be selected. A variety of strategies would be investigated in the diagnostic and treatment study proposed in this plan.

This project would identify and implement a suite of strategies to manage aquatic vegetation, the fishery, and zooplankton community to achieve water quality and clarity goals. The project includes an ongoing vegetation and fishery management plan.

OutcomeReduction in phosphorus load from internal sources estimated at 235 pounds annually; improved water clarity; more diverse aquatic vegetation community; improved aesthetics
Estimated Cost and Funding
Investigation, permitting, fish, vegetation, and
zooplankton surveys, and implementation of
strategies. Funding source is the District capital
levy.
$18,700 Design, surveys
$234,600 Construction
$253,300 Total
Schedule

One Year Prior to Implementation: Fish, vegetation, and zooplankton surveys, development of management plans

No Year Assigned: Implementation of strategies