Watershed Plan

2016 Watershed Implementation Plan

  Delavan Lake Watershed Implementation Plan Final 2-2-16

 

The Delavan Lake Watershed Implementation Plan

In an effort to preserve and protect Delavan Lake and its water quality, the Town of Delavan, with assistance from Berrini & Associated, LLC and Northwater Consulting, is in the process of completing a Watershed Implementation Plan the encompasses the entire Delavan Lake Watershed during the upcoming year. The purpose of this planning effort is to identify opportunities for implementing Best Management Practices (BMPs) that can reduce soil erosion and nutrient loading to Delavan Lake. This planning effort will complement and expand upon previous and ongoing efforts by the Town of Delavan, The Delavan Lake Improvement Association, The Delavan Lake Sanitary District, the U.S. Geological Survey, the Natural Resources Conservation Service, Walworth County Dept. of Land Use and Resource Management (LURM), the Kettle Moraine Land Trust (KMLT) and the Southeastern Wisconsin Regional Planning Commission (SEWRPC).

Please join us in our efforts to preserve and protect Delavan Lake

2014 Map

 

Delavan Lake is a 2,072-acre public access drainage lake located within the limit of both the Town and City of Delavan. It is an economically valuable resource that provides numerous recreational opportunities for Delavan and surrounding communities such as boating, fishing, swimming and scenic enjoyment. The Delavan Lake Watershed consists of approximately 26,500 acres of land primarily drained by Jackson Creek and Brown's Channel along with direct surface runoff from adjacent areas surrounding the lake as shown by the blue watershed boundary lines in the map above.

Preserving a Valuable Resource: Delavan Lake

Completed Projects

The Town of Delavan, the Delavan Lake Improvement Association, The Delavan Lake Sanitary District and the Kettle Moraine Land Trust have collectively funded, coordinated and implemented various projects and management practices throughout Delavan Lake and its watershed to reduce soil erosion, nutrient runoff and non-point source pollutant loading.

Dredging the Delavan Lake North Inlet & Brown's Channel

The Town of Delavan completed projects at two critically impaired location at the primary inlets to the lake, the North Inlet and Brown's Channel.  In 2007, approximately 3,000 cubic yards of nutrient rich sediment were hydraulically dredged from Brown's Channel; and in 2011, approximately 45,000 cubic yards of sediment were hydraulically dredged form the North Inlet of the lake where runoff from Jackson Creek flows through.  Both locations had filled in with excessive amounts of sediment, which impacted navigation and reduced the ability of both areas to trap sediment and phosphorus loads entering the lake form watershed runoff.

Restoration of Mound Road Ponds 

The sediment and nutrient control ponds at Mound Road were constructed in 1992 to trap and retain suspended sediment and phosphorus being transport from the Jackson Creek sub-watershed. By 2004, the ponds had gradually filled in the sediment and had lost much of their original storage capacity and trapping efficiency. AWDMR Lake Protection Planning Grant provided partial assistance to complete engineering work to implement a restoration project for the Mound Road Wetland. From 2004 to 2009, the Town of Delavan obtained permits from WDNR and then contracted to dredge sediment form the East Pond and the North Pond in an effort to restore volume for trapping sediment and phosphorus, and to protect Delavan Lake water quality.

Ponds

Watershed Best Management Practices (BMPs)

As a result of a cooperative efforts and partnerships between NRCS, Walworth County LURM; Kettle Moraine Land Trust; Delavan Lake Improvement Association; the Town of Delavan; and cooperative landowners, best management practices have been installed and implemented in the Delavan Watershed to reduce soil erosion and nutrient runoff. These installed BMPs include grass waterways, vegetated buffers, cover crops, underground outlets, nutrient management plans, etc., and have been a great start towards protecting water quality and reducing nutrient loadings to downstream resources.

Underground

Construction Site Erosion Control & Storm Water Management

In 1990, Walworth County adopted a County-wide Construction Site Erosion Control Ordinance that requires construction sites to have a county-approved Land Disturbance, Erosion Control and Storm Water Management Plan and Permit to contain soil, intercept sediment, manage storm water discharges and establish vegetation on construction sites to protect downstream water resources and property during and after development.

Erosion

A Plan for the Future

The Delavan Lake Watershed Implementation Plan is being developed to improve and preserve the water quality of Delavan Lake and its tributaries by reducing soil erosion and controlling nonpoint source (NPS) pollutant loading, while providing long-term water quality protection to Delavan Lake. This long Term Plan will include identifying specific sources of sediment and nutrient loading and recommend specific BMPs for future implementation. It will be consistent with U.S. Environmental Protection Agency (USEPA) and Wisconsin Department of Natural Resou8res (WDNR) watershed based plan guidance to address the nine key elements of a Watershed Based Plan as listed below:

  1. An identification of the causes and sources of nutrient loadings that will need to be controlled to achieve the load reductions estimated in t his watershed-based plan.
  2. An estimate of the load reductions expected for the management measures described in the plan.
  3. A description of the NPS management measures that will need to be implemented to achieve the estimated load reductions and an identification (using a map or a description) of the critical areas where those measures will be needed.
  4. An Estimate of the amounts of technical and financial assistance needed, associated costs, and/or the sources and authorities that will be relied upon to implement this plan.
  5. An information/education component that will be used to enhance public understanding of the project and encourage their early and continued participation in detecting, designing, and implementing the NPS management measures that will be implemented.
  6. A schedule for implementing the NPS management measures identified in this plan that is reasonably expeditious.
  7. A description of interim, measurable milestones for determining whether NPS management measures or other control actins are being implemented.
  8. A set of criteria that can be used to determine whether loading reductions are being achieved over time and substantial progress is being made toward attaining established water quality standards and , if not, the criteria for determining whether this watershed-based plan needs to be revised.
  9. A monitoring component to evaluate the effectiveness of the implementation efforts overtime, measured against the criteria established in the Plan.

Updates will be posted periodically as the Plan develops in 2015, and advance notification of informational public meetings will be provided.  Please contact the Town of Delavan for more information.