5.8.7 Parley Lake Internal Load Management Project

ProjectParley 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

A TMDL study including a phosphorus reduction plan is currently being developed for Parley Lake. Proposed reductions include control of external sources of phosphorus through various efforts in the watershed and internal load management. The TMDL identified a need to reduce internal loading by 1,129 pounds annually.

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. Management of invasive aquatic vegetation that contributes to lake water quality and usability issues would require annual treatment for three to five years.

OutcomeReduction in phosphorus load from internal sources; 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.

$17,200 Design, surveys

$214,400 Construction

$231,600 Total


2012 Fish, vegetation, and zooplankton surveys, development of management plans

2013 Implementation of strategies