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Water: Best Management Practices

Conservation Easements

Minimum Measure: Post-Construction Stormwater Management in New Development and Redevelopment

Subcategory: Innovative BMPs for Site Plans

Conservation easements are voluntary agreements that allow individuals or groups to limit the type or amount of development on their property. A conservation easement can cover all or just a portion of a property, and it can either be permanent or temporary. Easements typically describe the resource they are designed to protect (e.g., agricultural, forest, historic, or open space easements), and they explain and mandate the restrictions on the uses of the particular property. Easements can relieve property owners of the burden of managing these areas.  They do so by shifting responsibility to a private organization (land trust) or government agency better equipped to handle maintenance and monitoring issues.  Furthermore, in some cases, tax benefits might be realized by property owners who place conservation easements on some or all of their property.

Conservation easements may indirectly contribute to water quality protection. Land set aside in a permanent conservation easement has a prescribed set of uses or activities that generally restrict future development.

The location of the land held in a conservation easement may be evaluated to determine its ability to provide water quality benefits. Property along stream corridors and shorelines can act as a vegetated buffer that filters-out pollutants from stormwater runoff. The ability of a conservation easement to function as a stream buffer depends on the width of the easement and in what vegetated state the easement is maintained (see Riparian/Forested Buffer fact sheet).


Conservation easements are typically aimed at preserving agricultural lands and natural areas threatened by development. For rapidly urbanizing areas, conservation easements may be a way to preserve open space before land prices make the purchase of land containing important cultural and natural features impractical for governmental agencies with limited budgets. Conservation easements are not often used in ultra-urban areas, due to both the lack of available open space for purchase and the high cost of undeveloped land. In addition, private land trusts may limit the size and type of the land that they are willing to manage as conservation easements.


Conservation easements are designed to assure that the land is preserved in its current state long after the original owners no longer control the property. By agreeing to give up or restrict the development rights for a parcel of land, landowners can guarantee that their property will remain in a prescribed state for perpetuity while receiving tax benefits. Often, state agencies and private land trusts have specific qualifications for a property before they will enter into an easement agreement with land owners. Table 1 contains examples of criteria used by private land trusts to determine if a property is worth managing in a conservation easement.

Table 1: Typical criteria that land trusts use to determine feasibility of entering into conservation easement agreement



Natural resource value

Does the property provide a critical habitat or important environmental aspects worth preserving?

Uniqueness of the property

Does the property have unique traits worth preserving?

Size of land

Is the land large enough to have a natural resource or conservation value?

Financial considerations

Are funds available to meet all financial obligations?


Is the conservation agreement a perpetual one?

Land trust's mission

Does the property align with the land trust's mission and the organization's specific criteria?

Conservation easements have been used in all parts of the country, and many private groups, both nationally and locally, exist to preserve natural lands and manage conservation easements. States also use conservation easements and land purchase programs to protect significant environmental features and tracts of open space. Maryland has been nationally recognized for its programs that provide funding for state and local parks and conservation areas. The state is one of the first to use real estate transfer taxes to pay for land conservation programs. Several programs are funded through this transfer tax of one-half of one percent ($5 per thousand) of the purchase price of a home or land, or other state funding programs.  Conservation programs include:

  • Program Open Space. This program is responsible for acquiring 150,000 acres of open space for state parks and natural resource areas, and more than 25,000 acres of local park land. Every county must create a Land Preservation and Recreation Plan that outlines acquisition and development goals in order to receive a portion of the 50 percent that is granted to local governments (MDNR, no date).
  • Maryland Environmental Trust. This trust is a state-funded agency that helps citizen groups form and operate local land trusts.  It offers the land trusts technical assistance, training, grants for land protection projects and administrative expenses, and participation in the Maryland Land Trust Alliance (MDNR, 2001a).
  • Rural Legacy Program. This program is a Smart Growth Initiative that redirects existing state funds into a focused and dedicated land preservation program specifically designed to limit the adverse effects of sprawl on agricultural lands and natural resources. The program purchases conservation easements for large contiguous tracts of agricultural, forest, and natural areas subject to development pressure, and purchases fee interests in open space where public access and use is needed (MDNR, 2001b).

Regardless of whether a conservation easement is held by a government agency or a private land trust, certain management responsibilities must be addressed by the easement holder. The following is a list of some of these management duties:

  • Ensure that the easement's language is clear and enforceable.
  • Develop maps, descriptions and baseline documentation of the property's characteristics.
  • Monitor the use of the land on a regular basis.
  • Provide information regarding the easement to new or prospective property owners.
  • Establish a review and approval process for land activities stipulated in the easement.
  • Enforce the easement's restrictions through the legal system, if necessary.
  • Maintain property/easement-related records.

A number of limitations exist for using conservation easements as a stormwater management tool.  For example, conservation easements are often not an option in more urbanized areas, where the size, quality, and cost of land restricts their use. Some easements might also not be held in perpetuity, which means that land could still face development pressure in the future. Easements also may not provide for the filtering of pollutants from concentrated flows. More information on the filtering potential of stream buffers can be found in the Riparian/Forested Buffer fact sheet.

Maintenance Considerations

The responsibility for maintenance of property in a conservation easement depends on the individual agreement with a land trust or agency. While many organizations assume the responsibility for managing and monitoring a property, some land trusts leave maintenance responsibilities to the landowner and act only to monitor that the terms of the easement are met.


A conservation area's pollutant removal efficiency depends on how much land is conserved, the techniques used to conserve it, and the specific nature of the easement. Conservation easements are assumed to contribute water quality benefits, but no national studies proving this have been released.

Cost Considerations

Table 2 summarizes the costs of maintaining green spaces with different types of uses.

Table 2: Annual maintenance costs of different types of green space uses (Adapted from CWP, 1998)

Land Use

Approximate Annual Maintenance Costs

Natural open space
Only minimum maintenance, trash/debris cleanup


Regular mowing

$270 to $240/acre/year

Passive recreation



Center for Watershed Protection (CWP).  1998.  Costs and Benefits of Stormwater BMPs: Final Report.  Center for Watershed Protection, Ellicott City, MD.

Maryland Department of Natural Resources (MDNR). No date. Maryland Environmental Trust.  [http://www.dnr.state.md.us/met/ Exit EPA Site].  Last updated August 26, 2005.  Accessed September 8, 2005. 

Maryland Department of Natural Resources (MDNR).  2005.  Rural Legacy Program.  [http://www.dnr.state.md.us/rurallegacy/index.html Exit EPA Site].  Last updated April 29, 2005.  Accessed September 8, 2005. 

Maryland Department of Natural Resources (MDNR).  No date.  Program Open Space.  [http://www.dnr.state.md.us/pos.html Exit EPA Site].  Last updated August 1, 2005.  Accessed September 8, 2005. 

Information Resources

Brown, W.E., D.S. Caraco, R.A. Claytor, P.M. Hinkle, H.Y. Kwon, and T.R. Schueler. 1998. Better Site Design: A Handbook for Changing Development Rules in Your Community. Center for Watershed Protection, Inc., Ellicott City, MD.

Daniels, T., and D. Bowers. 1997. Holding Our Ground: Protecting America's Farms and Farmland. Washington DC: Island Press.

Diehl, J., and T. Barnett, eds. 1988. The Conservation Easement Handbook. Land Trust Alliance and Trust For Public Land, Alexandria, VA.

Schear, P., and T. W. Blaine. 1998. Ohio State University Fact Sheet: Conservation Easements. CDFS-1261-98, Land Use Series, Columbus, OH.

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