Sediment and Erosion

Green Lake is the deepest natural inland lake in Wisconsin. Through time its water quality has degraded, with relatively high phosphorus concentrations and zones of hypoxia. This project is quantifying the water quality of the lake and its tributaries, and it will provide information to help guide efforts to improve the lake.

Eutrophication of Delavan Lake accelerated from the 1940s to 1980s, resulting in a hypereutrophic lake with severe blue-green algae blooms. Extensive rehabilitation efforts were implemented to improve water quality. The USGS measured nutrients, suspended sediment, water quality, and plankton populations to quantify the effectiveness of rehabilitation efforts and guide future management decisions.

The USGS is evaluating the effectiveness of non-point pollution control measures in five watersheds in the Lower Fox River and Duck Creek watersheds and comparing daily phosphorus and suspended solids loads for each watershed.

The WinSLAMM model is used to identify sources of pollutants in urban stormwater runoff and to evaluate management alternatives for reducing pollutants. USGS studies provide stormwater flow and pollutant-concentration data for calibrating and verifying WinSLAMM for use in Wisconsin.

To better understand the quality of water flowing into the Great Lakes, the USGS is conducting water-quality analyses for nutrients, sediment, and toxic substances and estimating the amount (load) of these substances for tributaries to the Great Lakes. Information on the occurrence and distribution of contaminants is needed to provide baseline information, measure progress towards restoration...

SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Interactive, online SPARROW mapping tools allow for easy access to explore relations between human activities, natural processes, and...

This study identified major geomorphic processes and factors for Duluth-area streams, assessed their sensitivity to geomorphic change, summarized the effects of the 2012 flood. It also identified channel processes, sediment dynamics, and geomorphic setting can be used to assist managers in post-flood reconstruction activities and stream restoration.

The Kalamazoo River, a federal Superfund site, contains sediments contaminated with PCBs from historical paper mills. Dam control and erosion has exposed and mobilized the contaminated sediment, transporting and depositing it downstream. This study determined the historical geomorphic changes, measured bank stability, and evaluated the potential effects of future dam failure and removal scenarios.

Recently, elevated chlorophyll-a concentrations were found related to persistent algal blooms on Silver Lake in Oceana County, MI. Elevated chlorophyll-a concentrations, high phosphorus concentrations during summer months, as well as a decrease in water clarity indicated potential accelerated eutrophication processes during the last two years, and underscore a need to characterize water and...

The Winnebago Pool Lakes are shallow, productive drainage lakes that have accumulated nutrients from its mixed agricultural/forest watershed and from the Fox River. High phosphorus concentrations often result in severe blue-green algae blooms that can produce harmful toxins. The USGS is evaluating the water quality and phosphorus budget of each lake and modeling eutrophication responses.

North Fish Creek, Wisconsin, has accelerated erosion and sedimentation that negatively affects aquatic habitat. This project monitored three rehabilitation projects (including submerged flow-deflecting vanes) to determine their effect on bluff erosion rates and sediment volumes, and to describe the upland land cover and soils. This data will help guide runoff management and bluff restoration...

Riparian grazing allows cattle free access to streams, but may accelerate erosion by the removal or trampling of vegetation. This study measured stream bank erosion, channel morphology, and stream substrate through seven experimental intensive-rotational pastures. It also evaluated the use of photo-electronic erosion pins (PEEPs) for measuring bank erosion in this type of geomorphic setting.