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A municipality may express an interest in acquiring specific land (or easements thereon) for trails, streets, parks, open space networks and other public purposes by establishing an “official map” that “reserves” this land. If a landowner seeks to develop reserved land, the municipality has a year to pursue acquisition of the land from the owner before the owner may freely build or subdivide.


A municipality may more effectively provide for future trails, parks, networks of open space, road improvements, or other public uses by identifying the location of key public grounds and infrastructure in advance of the public’s need and reserving the necessary land on an official map. By reserving the land, the municipality expresses its intent to acquire that specific land at some future date. This expression of intent does not affect existing property ownership; landowners still own and control their land. However, the owners are constrained in building on, subdividing or otherwise developing the reserved land until (1) they receive a special encroachment permit or (2) they provide written notice of intent to develop and then allow the municipality up to a year to acquire the land from them.

The municipality and landowner may negotiate the sale of the reserved land or an easement, or they may agree to an alternative approach that will still meet the public need. If negotiations fail, the municipality may use its powers of condemnation, although municipalities rarely exercise these powers. If the municipality does not acquire the land within a year of the notice, the reservation lapses and the owner is free to build or subdivide following the normal regulatory process.

Adoption of an official map is appropriate for a county or local municipality that has enacted a comprehensive plan and has a clear sense of where future parks, trails, streets or other public infrastructure and areas will be needed. Sixty-four or more Pennsylvania municipalities and one county have adopted official maps as of early 2011. Most officials surveyed from these local governments indicated that they believe the planning tool is a worthwhile and effective means of securing lands for future needs.

Benefits of adopting an official map include the following:

  • The official map greatly increases the likelihood that key conservation resources will be protected by enabling the municipality to reserve land for future parks, trails, greenways and other recreational and conservation purposes without having to immediately commit to purchasing the land or easements.
  • In developing an official map, a municipality effectively prioritizes its acquisition needs, enabling it to focus its resources on properties that are most important to the community.
  • When integrated with Growing Greener: Conservation by Design and/or Transfer of Development Rights zoning, the overall conservation value delivered is greater than what these tools would deliver independently.

To implement an official map, you will need the following:

  • A comprehensive plan (and preferably solid zoning and subdivision ordinances that are consistent with the comprehensive plan).

  • Willing and committed municipal board and planning commission members as well as legal counsel.

  • Official maps are commonly backed by a funding mechanism whereby a municipality has the financial wherewithal to support its map designations when the time comes.

A potential obstacle to official map adoption is that landowners, developers and others may have strong concerns that the municipality will use condemnation powers to acquire land reserved on the official map. Note that, in reality, condemnation is hardly ever used.

What is an Official Map?

An official map shows the locations of planned future public lands and facilities such as streets, trails, parks and open space. The official map expresses a municipality’s interest in acquiring these lands for public purposes sometime in the future and notifies developers and property owners of this interest. Official maps may be used by townships, boroughs, cities, and counties. An official map is not a municipal base map, existing or future land use map, a zoning map, or any map in a comprehensive plan, though these can be used to help identify areas for the official map ordinance. Section 107(b) of the Municipalities Planning Code (MPC) defines an official map as a “land use ordinance” with the map as the primary component of an official map ordinance. If a landowner seeks to build on or subdivide land noted on the official map, the municipality has up to a year to acquire the land from the owner before the owner may freely build or subdivide.

What Are the Benefits?

  • The official map can help focus limited financial resources on projects that meet and advance community goals.
  • The official map helps municipalities make improvements such as connecting and improving the local street network, intersection improvements, protecting important natural areas, and providing more green space, recreation facilities, trails, and sidewalks.
  • The official map saves time and money by informing property owners and developers of municipal goals and intentions in advance of development plans being made.
  • The official map is an effective negotiation tool for municipalities, helping to ensure that development is compatible with and supportive of public goals.
  • The official map supports other land use management tools such as Growing Greener: Conservation by Design and Transfer of Development Rights.
  • The official map addresses public land and easement acquisition needs that generally can’t be dealt with solely through zoning and subdivision and land development ordinances. • The official map gives municipalities a competitive advantage in securing grants.

Use in Pennsylvania

Sixty-four or more Pennsylvania municipalities and one county have adopted official maps as of early 2011. These municipalities are located in 15 counties. The greatest concentration is found in eastern and southcentral Pennsylvania, but the official map is also used in Centre, Allegheny, Butler and Erie Counties. An inventory that describes the focus (transportation, trails, parks, etc.) of each map can be found in Appendix A of “The Official Map: A Handbook for Preserving and Providing Public Lands and Facilities.” Most local government officials interviewed for this guide found the official map to be a worthwhile and effective means of securing the areas and improvements included on the map.



(WeConservePA expects to publish additional content including coverage of the intersection of conservation, the municipal codes, eminent domain and official map reservations at a future date.)