The acquisition of land or interest in land (e.g., conservation easements or purchase of development rights) that provides protective buffers around reservoirs, priority stream segments, wetlands, and other critical areas within the source water protection area is a very effective method to protect source water quality.

Ownership of key land areas allows a community to prohibit or control activities that could impair drinking water quality. In addition to the pollution prevention and restoration values received from owning the land, it can also provide other benefits to the community, such as preserving wildlife habitat, providing recreational opportunities, and reducing flood damage.

Communities can target and acquire land parcels themselves, or they can work with other groups to protect land. Local and regional land trusts are independent nonprofit organizations formed to accomplish resource protection goals. Land trusts have successfully worked with local governments to protect drinking water sources by acquiring land within wellhead protection areas and in critical areas of water supply watersheds.

For a listing of land trusts in Pennsylvania, visit


Official Map

Proactive planning measures must be considered if municipalities are to ensure the preservation of important community resources such as public water supply areas. Community water systems must be considered in the context of an essential perpetual resource; yet planning is often non-existent from the perspective of what is needed to support the vital function of the public water supply over the long term.

The official map offers a powerful, but under-utilized planning tool for ensuring that water supply recharge lands, riparian buffers, and other water supply ecosystem areas will be protected from non-compatible land uses.  The official map is authorized by the Pennsylvania Municipalities Planning Code.

What is An Official Map?

The Official Map is a map and ordinance that identifies both existing and proposed public lands and facilities within the entire community or in a specific area or neighborhood. The map is a declaration by the municipality that it may eventually need the mapped areas for uses and facilities that will advance and safeguard the health, safety, and welfare of the residents. It identifies properties that the municipality reasonably expects for public purposes or improvements. Only those areas should be mapped which the municipality is able and willing to purchase outright or on which it can acquire easements. Contrary to a common misconception, the Official Map is not a zoning map that shows the districts related to ordinance text that regulates the uses of land in the community. Even if the official map begins on a limited scale with the source water protection area delineation for 5 year time of travel for example, it can later be amended to include additional features.

Benefits of an Official Map

  • The Official Map provides a legal means for reserving sites for public use. Development of the designated land may be delayed for up to one year. Adoption of the map does not in itself establish a street or imply that the municipality has taken the land; that requires a municipal purchase, mutual agreement, or condemnation of the land through eminent domain.
  • An Official Map can indefinitely restrict development of land for streets and watercourses. But where a landowner applies to subdivide or develop a parcel of land designated for public grounds or facilities, the municipality has one year to acquire the area designated for public improvement. Otherwise, the reservation becomes void.
  • The map allows for public and private cooperation by informing developers up front of the municipality’s long-range growth plans. Occasionally, developers opt to pay for the additional roadways and other improvements rather than wait a year for a decision by the municipality. This is a distinct savings to the taxpayers.

For more information, visit

Examples of Land Preservation for Water Supply Protection

Musser Gap – State College Borough Water Authority, Centre County PA

View Musser Gap Maps

The Magic of Musser Gap – Protecting an Extradordinary Drinking Water Resource

Musser Gap, a 423-acre mountain gap on Tussey Ridge between Shingletown Gap and Pine Grove Mills that was purchased by Clearwater Conservancy on August 8, 2006,  recharges the groundwater in the vicinity of the Harter and Thomas wellfields. These wells provide drinking water to 38,000 residents in the State College area.

The Harter and Thomas wells have been supplying the area with high-quality drinking water since the 1940s, but a proposed residential development in Musser Gap could have had a huge impact as new pollutants percolated into the groundwater system and migrated toward the wells.

State College Borough Water Authority ended up being a major funding partner in the purchase of Musser Gap. “As the acquisition project progressed, State College Borough Water Authority conducted dye-trace testing to find out how quickly potential pollutants would show up in the drinking water wells,” according to Katie Ombalski, Conservation Biologist and project manager for the Musser Gap purchase.

“Under low stream flow conditions, the dye showed up in the wells in about three weeks; in high flow conditions, it took only two days.” Mountain gaps serve as primary contributors to groundwater recharge in the Spring Creek Watershed. In addition, any contamination introduced through these mountain gaps can quickly reach the groundwater aquifers that they feed.

Musser Gap was the single largest purchase in Clearwater Conservancy’s history. The land was purchased from a private landowner who planned to develop the area into residential housing. Ferguson Township, the municipal home of Musser Gap and also a strong funding partner for the acquisiton project, was concerned about the development proposal but, due to zoning regulations, could not prevent it. The effort required detailed knowledge of the source water protection area that supports State College Borough Water customers, awareness of the ecological and recreational value of the property and above all, a commitment to partnership.  It shows what can be accomplished with collaborative efforts, community commitment to a sustainable future and the leadership of a dedicated land conservancy.

According to Clearwater Conservancy: “The property consists of a fragile 423-acre mountain gap environment that recharges groundwater, provides important wildlife habitat and now serves as a recreational gateway to Rothrock State Forest. In 2007, ClearWater Conservancy transferred the property to DCNR Bureau of Forestry, making it part of Rothrock State Forest. In partnership with DCNR, ClearWater Conservancy purchased an additional 281 acres on the north face of Tussey Mountain in 2014 and transferred it to Rothrock State Forest, further protecting this treasured resource.”

Bethlehem Authority’s Historic Conservation Deal

The Bethlehem Authority protected its 22,000 acre source watershed area in an historic conservation deal.   Read more>>

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