Water Quality Programs Improving Health of Delavan Lake


Lakefront property is only as valuable as the resource abutting it. If the lake water quality is poor, then the desire to utilize and enjoy the lake will be marginal. That's why there are communities that are becoming proactive about improving the water quality of their local cherished lakes. The Town of Delavan in southeastern Wisconsin is one of those communities that understand that a healthy lake means a healthy Town of Delavan and happy lake home residents who pay substantially higher taxes for their lakefront property.


The Town of Delavan’s Lake Committee maintains a water quality monitoring program for Delavan Lake and its entire watershed area.  The program is jointly financed by the Delavan Lake Sanitary District, the Town of Delavan, and the United States Geological Survey (USGS). It includes monthly sampling of lake water at various locations: Jackson Creek at Mound Road, manually collected data at Highway 50, and samplings from eight prime potential 'trouble spots' throughout the watershed.


The purpose of the comprehensive monitoring program is to systematically gather the information that the Lake Committee and its expert advisers need to guide its ongoing efforts to improve Delavan Lake water quality.


Samplings are conducted according to strict USGS protocols.  Water samples from each of the 8 sites are sent to fully-certified labs in Baraboo for analysis, www.ctlaboraties.com.  Five separate analyses are being conducted on each sample. They include total and dissolved phosphorus, nitrate, kjeldahl nitrogen, and suspended solids.


“The data is evaluated by the town,” said Town of Delavan Chairman Ryan Simons.  “Should one location indicate a particularly high concentration of nutrients or sediment, additional sampling is conducted upstream of the present sampling location to identify the source of the high concentrations. Once the source is identified, specific actions will be taken,” he said.



An essential part of the overall watershed monitoring program is the automated sampling site at Jackson Creek, maintained by the USGS.  Jackson Creek accounts for about 70 percent of all of the surface water entering Delavan and about half of the total phosphorus entering Delavan Lake from the watershed.  The station measures stream flow in real time.


The automated equipment at Mound Road also collects samples of the stream water during high flow periods.  These samples are being checked for total and dissolved phosphorus and suspended sediment concentrations.  The stream flow and concentration data will provide estimates of nutrient loading. The Mound Road Sedimentation Ponds, rebuilt in 2009, are a critical part of the Delavan Lake system, and the data resulting from both sets of sampling will provide information to describe how they are functioning. The Lake Committee intends to conduct a detailed study this spring of the rate at which sediment has been accumulating in the ponds.


“The information gathered at the station will complement sampling being conducted at the Highway 50 bridge,” said Simons. “The data collected at Mound Rd and Highway 50 will help determine the effectiveness of the recently completed Inlet dredging project,” he continued.


The In-Lake element of the program was restarted in 2012.  The first sampling of 2012 was conducted through the ice by USGS staff.  The second sampling took place after the ice left the lake.  The results, are published on the Town’s web site. Click on the Lake Information tab.  The Town is actively working with others to be able to reliably summarize the data.