GEOLOGY:  The Chartiers Watershed is located in the Appalachian Plateau physiographic province. The plateau is noted for its narrow, steep-sided valleys. Cyclic sequences of sandstone, shale, claystone, limestone, dolomite, and coal are the exposed rock types.  The soils in the Chartiers Watershed are derived from very landslide prone rock. 

When soils and parent rock occur on steep slopes, landslides are the frequent by-product of development.

The prevalence of low permeable, clay soils in the watershed means that septic systems do not work effectively here, impairing water quality by groundwater contamination.  Combining the water runoff from land areas having low permeable soils and impervious urban surfaces in pipes with sanitary sewer overflows as combined sewer overflows (CSO's) creates additional sewage pollution to our waterways. 

Twenty coal seams are exposed in Allegheny County, and the Pittsburgh coal seam is of significant economic importance.  Mining has led to abandoned mine drainage, creating another water quality issue. 

Some of the soils located in valley bottoms have previously been altered by man through development and are located adjacent to and within the floodplains.   

Reducing the ability of soils to allow water to effectively drain an area enhances flooding.

LAND USE:  Traditionally, land use activities have been encouraged by older and outdated zoning codes.  Urban sprawl develops under these conditions.  Witness the  lower watershed east of the I-79 transportation corridor, which is dominated by this residential, commercial and industrial land use. 

Land use pie chart showing that the watershed is about evenly divided between residental/agricultural use and natural forest

Agricultural farmland, open space and forested land uses predominate in the upper watershed and the western portion of the lower watershed.  But, as transportation facilities have expanded, urbanization and development is taking place in areas of the watershed that have historically not observed these types of pressures.  Areas of the watershed that are near the Allegheny County line and the Southern Beltway need to be prepared with community planning and zoning to attempt to protect those communities from the impact of urban sprawl.  Recent amendments to the Municipalities Planning Code (Acts 67, 68, 127) encourage municipalities, including counties, to work together in planning and implementation.  Without safeguards in place, in terms of sound zoning, planning, and inter-community cooperation, to protect the area's resources, degradation of land and subsequent degradation of water quality will result.

Proper planning is needed in order to control negative impacts of sprawl

Urban Sprawl

Urban sprawl can be controlled by proper land use planning. Municipalities manage land use through zoning ordinances, sub-division and land development ordinances, a comprehensive plan and an official map.  An Inter-Municipal Framework is a process where municipal governments and local organizations work together to improve local conditions such as infrastructure, environment, and education. 

Urban sprawl is partially caused by the construction of new transportation facilities.


Industrial/commercial land use and abandoned industrial sites or brownfields are located primarily along or near major transportation corridors such as U.S. Interstates 79 and 279 and State Routes 19, 22, 50, 60, and 980. Construction of the proposed Southern Beltway will result in urban sprawl without proper land use ordinances and cooperation between affected municipalities.

An encompassing organization can promote conservation of greenspace for the entire watershed


Several local conservation groups exist throughout the watershed.  They are very effective in bringing implementation projects identified in the Rivers Conservation Plan to their respective areas of the watershed.  However, the watershed lacks a strong, encompassing organization with a paid, full-time watershed coordinator to coordinate projects, encourage wise land use and promote conservation for the entire watershed.