Lakes Grant
Large Scale Lake Planning
LPL170819
2019
Complete
The objectives of these investigations were to examine the development of summer algal blooms in Big Round Lake (Table 1) in relation to P loading from the Straight River watershed and from bottom sediment during temporary anoxia. The goals of this research were to develop an estimate of summer watershed and sediment-derived internal P loading for use in P budgetary analysis and future forecasting of the impacts of internal P loading management on water quality.
Letter approving the 2019-2023 Aquatic Plant Management Plan for Big Round Lake in Polk County.
Although a comprehensive lake plan is in effect from 2016 through 2025, this aquatic plant management plan (APMP) was initiated to focus on curly-leaf pondweed, phosphorus loading, and algae blooms. The Big Round Lake Protection & Rehabilitation District (“District”) was formed in 1967 and is the entity sponsoring this APMP. The District partnered with Aquatic Plant and Habitat Services LLC to create a 5-year management plan that is WDNR-approved and District-adopted. Public input was gathered in April 2019 (Section 10.0) and the management plan was released for public and WDNR review in June 2019.
Water chemistry data.
In shallow lakes there is intense interaction at the water sediment interface. Therefore, understanding sediment water interactions is crucial to understanding the nutrient dynamics of shallow lakes such as Big Lake (Scheffer, 1998). The sediments demand for oxygen is high as it is broken down by microbial communities. At the sediment surface, a difference of a few millimeters in oxygen penetration is the critical factor regulating exchange of nutrients and inorganic elements such as iron between the sediment and water. Under aerobic conditions, the exchange is largely from the water to the sediment. Under anaerobic conditions, however, phosphorus can move from depths up to 10 cm deep and be released into the water column (Wetzel, 2001). An analysis of the hypolimnetic nutrients of Big Lake has implications for best management actions in 2016 to 2018.
Grant Awarded
Grant LPL170819 awarded