DEP Home : Water : Special Protection Areas
Use the Special Protection Area watersheds map to locate them and learn about their waterbodies.
Use this map to locate and learn more about Special Protection Areas.
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Impervious surfaces are those which do not allow water to filter into the soil. They include paved roads, parking lots, sidewalks and buildings.
Rainwater and snowmelt that infiltrate (soak into) the soil can be taken up by plants. Or they can move deeper, recharging (adding to) the water held between soil particles. Water that is stored below the surface is called groundwater.
Rainfall, infiltration and groundwater recharge are just a few components of the hydrologic (water) cycle. Reducing the total area of impervious surfaces in a watershed helps to maintain this natural hydrology (the natural cycling of water) within the watershed.
A Special Protection Area (SPA) is a part of the County that has high-quality or unusually sensitive water resources or other environmental features. Examples of such resources are high-quality streams, sensitive wetlands, and soils prone to erosion. Special measures—especially around construction sites—and land-use controls are implemented to protect these resources and features.
The SPA Program was established in 1994 by Montgomery County Code Chapter 19, Article V (PDF, 15 pp, 41K).
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The Maryland Department of the Environment (MDE) provides guidelines for which best practices should be used during urban development and on construction sites to minimize stormwater pollution and to protect water resources. In Montgomery County, local authorities such as the Montgomery County Department of Permitting Services and Department of Environmental Protection administer these state-mandated design guidelines.
State regulations for stormwater management are included in the Maryland Department of the Environment Stormwater Design Manual, which requires the use of three basic management techniques to control stormwater from new development and construction activities:
The requirements of the SPA Program (as specified in the Montgomery County Code) are more restrictive than the regulations established in the MDE Stormwater Design Manual and apply only to areas within Montgomery County designated as SPAs.
The following are examples of best practices and stormwater management techniques mandated in the SPA requirements to minimize impacts on water resources. They are designed to limit disturbance of the earth and to promote rapid stabilization of disturbed areas.
Within SPAs, plans for new construction must include techniques to minimize large cut-and-fill activities that modify the natural slopes and grade of the land.
A silt fence marks a stream corridor, where trees and topography are left intact, at the edge of a new development site.
Additional information on stormwater management structures can be found in the Maryland Department of the Environment Stormwater Design Manual.
See examples of stormwater management techniques that can be used in SPAs.
For all construction sites in the County, the Department of Permitting Services requires a Stormwater Management Concept Review. In the review the contractors specify, at the preliminary design stage, how they will prevent damage and pollution to local streams and waterways. For new construction sites within SPAs, a Water Quality Inventory and/or a Water Quality Plan is required instead of a stormwater concept review.
The County Council has designated four areas within Montgomery County as
SPAs. New SPAs are officially designated by the County Council, but anyone may propose an area for designation.
Each SPA falls within one of the Master Plan Development Areas. Montgomery County has developed master plans for these areas, which provide a comprehensive view of land-use trends and future development opportunities.
Use the Special Protection Area watersheds map below to locate them and learn about their waterbodies. Click within the red boundaries area of the map or type in a street address below to see:
Clarksburg SPA is the northernmost SPA. It generally encompasses the Little Seneca and Great Seneca watersheds east and west of I-270, north of Old Baltimore Road, and south of Comus Road. In 1994 the Clarksburg Master Plan established the first SPA, the Clarksburg SPA.
Currently, a 15% impervious limit is recommended for specific sites on the west side of I-270.
Piney Branch SPA was established in 1995, and it falls within the Potomac Master Plan Area near Shady Grove and Travilah Roads.
There is currently no impervious limit in Piney Branch SPA; it is nearly at maximum build-out.
The SPA regulations are not intended to be applied to properties with existing single-family residences or to other legally existing land uses if such uses are not changing or expanding. There are very few limits on what private homeowners may do on their land. If you own or purchase a single-family home in an SPA and maintain it as a residential property, SPA regulations do not affect the use of your property. Expansions and additions by the homeowner are allowed, consistent with zoning regulations and any lot-specific restrictions on the record plat, such as conservation easements. You may install a pool, deck, shed, gazebo or tennis court on your property if it is consistent with zoning laws and any lot-specific restrictions and if the use is accessory to an existing single-family residential dwelling.
The SPA regulations and guidelines are intended to incorporate stringent water resource protection measures into new and expanded land development projects. If land-disturbing activities are proposed on existing property, they might be subject to the provisions of the SPA regulations. Activities triggering the regulations include a new or amended development plan, diagrammatic plan, schematic development plan, project plan, special exception, preliminary plan, or site plan.
Read a Special Protection Areas (SPA) overview