Rehabilitation of Laurel Creek dam is almost done

From staff reports

LEWISTOWN – A rehabilitation program at the Laurel Creek Dam is nearing completion in the Juniata Valley, and experts expect repairs to be complete in July.

The Municipal Authority of the Borough of Lewistown owns and operates the dam, which supplies the public with drinking water. MABL has been utilizing the services of Uni-Tec Consulting Engineers Inc. during the two-year project to fix the dam.

Patrick Ward, Uni-Tec’s president, wrote an article that was published recently in the Pennsylvania Municipal Authorities Association’s magazine, “The Authority,” about the dam and the details of the rehab program.

“The Laurel Creek Dam is a 135-foot high earthen structure. The dam has outlet works and a spillway constructed of steel and concrete. The normal storage capacity of the Laurel Creek Dam is 924 million gallons, capturing flow from a 13-square-mile drainage area. Construction of the dam was approved by the Commonwealth of Pennsylvania, Department of Forests and Waters, Water and Power Resources Board by permit issued in 1968. The dam was put into service after construction completion in 1971.”

The dam is located in Armagh Township, just off U.S. 322 in Seven Mountains.

Ward says the water in the reservoir has been lowered on purpose, to accommodate the construction.

“A first thought might be that a drought is underway, or worse yet that the dam is leaking. Fortunately, neither is true,” Ward writes.

Before beginning construction work, the necessary lowering of the water level in the Laurel Creek Reservoir, by some 600 million gallons of water, was accomplished by increasing the flow through the dam drain system.

For those worried about the water supply, Ward states in his article that MABL maintains three water supply wells in addition to the reservoir supply. In the event that water demands exceed available supplies from the reservoir, MABL has the alternate means of supplying the water from its wells through its water treatment plant.

The dam components were put through a number of extensive data-gathering tests and examinations such as underwater video inspections, soundings, ground penetrating radar exams, and core borings to obtain samples for laboratory testing. The data gathered from the in-depth examination formed the foundation of a rehabilitation plan devised to restore the dam spillway and outlet works to a “like new” condition, Ward writes.

According to the article, MABL opted to perform the mechanical aspects of the outlet works rehabilitation effort with in-house staff. Pricing received from public bidding and evaluation of staff and equipment capabilities showed MABL had the ability to complete the work with significant cost savings.