LWA Creates Strategic Sediment Removal Plan (USA)

Lake Wildwood Association (LWA), located between Chicago and Peoria, Illinois has been dealing directly with the challenges associated with sedimentation in their lakes for over 20 years.

Sediment removal began almost from the time that the Lake was built in 1968. By 1972, the Association had purchased a Mudcat that sucked up the unwanted silt and deposited it in the middle of the lake. By the late 1990’s, it was apparent that this would not work as a long-term solution.

In 2002 The Board of Directors created a 30 year sediment removal and management plan (2002-2031).

They looked at 3 different options:

A) hiring a professional dredging company,

B) leasing dredging equipment, or

C) purchasing a new dredge.

Options B and C would require training Association staff as operators of the dredging equipment.

Consulting Firm was hired to provide Lake Wildwood Association with a 30-year cost analysis based upon the 3 options. The estimates ranged from $2,500,000 for contract dredging to $1.5 million for in-house dredging to $5,000,000 for projects to minimize the silt that was entering the Lake which left LWA in a difficult position of trying to make a long-term management decision based on wide ranging potential costs. Lake Wildwood Association decided to purchase their own dredging equipment and utilize existing staff and volunteers to operate the equipment.

After nearly a decade of in house dredging, the LWA Board of Directors was unable to quantify and verify results and costs escalated. When reviewing the budget requests from the lakes and dam committee, they realized they were spending a lot of resources without having clear information on how successful the sediment removal process had been over the years.

LWA decided they needed to quantify the sediment problem to create a sustainable sediment management plan. The President of the Association spearheaded an effort to get a hydrographic and sediment survey completed. The President and Lakes & Dams Committee contacted several hydrographic survey companies and chose The Mapping Network to provide this service based on experience in the industry and the Mapping Network’s clear understanding and attention to the needs of the LWA.

The primary objective of the hydrographic and sediment survey was to better understand the condition of the lake by charting the existing lake contours along with mapping the sediment thickness throughout the lake. Once the mapping process was completed the Association would be able to identify those areas that needed dredging and quantifying the amount of material to remove. This would allow for more precise budgeting and more cost effective and efficient dredging.

LWA was excited to have information based on real numbers (lake and sediment survey). The hydrographic survey results are an essential part of the decision making process with regards to the sediment removal planning. After 20 years of dredging and several studies performed by consultants the Association felt for the first time they finally understood the problem and how to manage it. The information provided by the Mapping Network survey gave the Association a clear overall picture of the lake, the areas of most concern and the scope of the silt problem. In addition, the information equipped Lake Wildwood with the means by which to develop short and long-term projects of greater sustainability and accountability.

Lake Wildwood Association goal is to complete the dredging in heavy silted areas identified through the Mapping Network survey, finalize several projects to minimize the amount of silt entering the lake and launch a continuing program to monitor the lake health, chart changing contours and finally to replace costly and inefficient blanket dredging with cleanout of specified problem areas identified during the hydrographic survey process.

Understanding the true extent of the lake sediment distribution in the lake is estimated to save the Association $200,000 to $300,000 in costs over the next 10 years through strategic dredging planning. LWA will be using the hydrographic survey information as a baseline for all future work and will adjust the map as dredging continues.

The primary problem was the lack of adequate information about the lake contours and the extent of sedimentation hindering the Association’s ability to make the best decisions regarding removal and reduction. Lake Wildwood Association now has the facts needed to create a comprehensive plan to cost effectively and efficiently maintain a healthy and vibrant lake ecosystem and recreational area.

[mappress]

Press Release, October 12, 2012