Maintaining the structural integrity and functionality of a dam and its associated principal and emergency spillway components is a requirement for all state regulated facilities. For all other owner-operated and maintained impounding facilities, maintenance may not be required, but it still remains essential for protecting the dam, its owner and the general public.

Regardless of their size, impoundments are constructed for any number of purposes, including aesthetics, recreation, water supply, water quality, flood control, sediment control and even to generate energy. Whatever the reason, the initial construction of a dam requires a significant investment of time and resources. A good maintenance program helps protect that investment by prolonging the life of the dam and helping to protect the dam against deterioration and a potential failure.

For those impoundments that are state regulated, the Department of Conservation and Recreation (DCR) has recently announced that grant funding is now available for private dam owners and local governments, which may be used towards performing engineering analysis, repairs and developing a maintenance program. Unfortunately, non-state regulated facilities are not eligible for this funding. However, the cost of such a maintenance program is small compared to the potential expense associated with major repairs, litigation, loss of property and loss of life.

Generally, a good maintenance program involves developing an Operations and Maintenance (O&M) manual that presents a maintenance schedule and a maintenance checklist to use for routine inspections of the facility. Maintenance inspections generally involve frequent weekly or monthly visual inspections performed by the dam owner to ensure that general maintenance requirements are being met. In addition, annual or semi-annual inspections should be performed by a professional engineer that should involve operating any mechanical controls for water flow through the dam, inspecting all outlet components for deterioration, and inspecting the dam itself for signs of failure or potential triggers for failure, such as rodent holes or trees growing on the dam embankment.

Regular maintenance of the dam involves making sure that all of the facility components are protected and kept in good working condition. Metal components are generally maintained to prevent rust from prohibiting its proper operation. Cracking and spalling concrete components are maintained to prevent leaking and potential failure. In addition, the embankment itself should be carefully inspected and maintained to prevent seepage and potential failure.

The biggest threat to an earthen embankment is external and internal erosional processes. While external erosion can be easily spotted during a routine visual inspection and repaired before significant damage occurs, internal erosion called "piping" is underground and its extent is more difficult to determine. For that reason, piping is more likely to occur unnoticed until significant damage or complete failure of the dam occurs. For this reason, one of the most important maintenance items for protecting an earthen dam is to maintain grass covered embankments free of rodent holes and without any trees allowed to grow on the impoundment.

Trees observed to be growing on the embankment or within 25 feet of the embankment fill should be removed as soon as possible. The complete root system of the tree should be removed and the embankment backfilled with suitable material. Similarly, rodent holes should be tended to regularly. Dams should be mowed at least twice a year to allow a more thorough visual inspection of the embankment surface so that rodent holes and external erosion may be more easily noticed. Burrowing rodents should be removed and their burrows plugged with suitable material. It is recommended to seek the consultation of a professional engineer whenever making repairs to an earthen embankment.

If you have questions concerning dam inspections, maintenance, grant funding, or developing an Operation and Maintenance Manual, please contact Mike Marsala, Frank Graziano, or Mike Rolband.