The dam at the east end of Woodbury Pond in Litchfield could soon undergo a temporary fix to stop a leak while the town works with engineers on a more permanent structural solution. Joe Phelan/Kennebec Journal file

LITCHFIELD — Officials last week unanimously approved the second phase of the Woodbury Pond Dam’s repair, which includes permitting for sandbags, geotechnical exploration and conceptual engineering design. Altogether, costs for this phase are not to exceed $45,800.

Problems were discovered this spring when dam keeper Terry Averill found that the stone riprap next to the right side of the upstream training wall had began to settle, and that water was seeping around 7 feet and intensifying at 7 1/2 feet.

Wright-Pierce, a Topsham based engineering firm, surveyed the dam with geotechnical engineering consultants from Haley & Aldrich, and found that the riprap next the upstream wall was continuing to settle between two visits less than a month apart. They determined that the settlement was caused by a pause of materials within a 10-foot area of the embankment.

An item was then added to the town meeting warrant to include $55,000 in the municipal budget to help repair the dam, which residents approved.

At first, engineers suggested undergoing a short-term fix which would keep the area stable for up to two years, which would give the town ample time to raise money for one of three long-term fixes: installing a concrete core within the dam embankment, installing a steel sheet pile cutoff wall on the upstream face of the dam, or installing a concrete secant pile wall on the upstream face of the dam.

But town officials later decided to opt for a more brief short-term fix that would last seven months and then go straight to the installation of a steel sheet pile cutoff wall. Through this plan, the short-term fix would only include installing sandbags and would forego pressure grouting — a move that Town Manager Kelly Weissenfels said could save the town up to $150,000. The town will also install the sandbags themselves for additional savings.

The recently approved phase of the project will include obtaining permits through the Maine Department of Environmental Protection and the United States Army Corps of Engineers.

The Maine Department of Environmental Protection permit would be authorized under “maintenance repairs.” According to a description of the work submitted by Wright-Pierce, MaineDEP defines temporary projects as anything installed for less than seven months. Engineers said USACE will also require permitting under a maintenance general permit.

In addition to permitting, Wright-Pierce will also conduct a high intensity survey with an unmanned aerial system to obtain detailed topographic information, and to supplement this with a GPS survey of the existing embankment, focusing on the upstream right-side of the embankment area including the existing riprap.

Haley & Aldrich will also work with Wright-Pierce in solidifying design recommendations for a long-term fix, this includes developing a geotechnical field investigation work plan, conducting site visits and laying out borings, coordinating with a drilling subcontractor, and preparing a health and safety plan. After conducting a geological review and report of the conditions surrounding the affected area of the dam, both Wright-Pierce and Haley & Aldrich will work on preliminary designs, determine a preliminary cost estimate and present the recommended course of repair to the town.

The breakdown of costs for this phase are $3,000 for sandbag layout and permitting, $35,000 for geotechnical evaluation and recommendations, $5,800 for the survey of existing conditions, and $2,000 for the monitoring plan and quarterly survey review.

Looking ahead, the next phase will include the final design and construction documents, after which the town will be able to put the project out to bid.

Weissenfels said sandbag placement is tentatively scheduled between late September and early October.

He added that Averill and Woodbury Dam Committee Chairman Mark Evans visited State Department of Defense, Veterans and Emergency Management on Tuesday to help with funding efforts.

“An assistant dam inspector and a representative of the Maine Emergency Management Agency were happy to help them copy some of the technical and historical records,” said Weissenfels. “We hope to use those records as part of an application to Maine’s Dam Repair and Reconstruction Fund. The application to the state for a low interest loan is one funding option we may pursue, but that loan is limited and we don’t think it will be able to cover all our costs.”

Anyone interested in making donations toward dam repairs can do so at the Litchfield Town Office, or via the Preserve The Woodbury Pond Dam GoFundMe page, which was set up by the Woodbury Dam Committee.

As of Wednesday, Weissenfels said no further changes have been noted in the dam.

Related Headlines

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.