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StormwaterPrint: Introduction

StormwaterPrint is a Geographic Information System (GIS) application developed by the Maryland Department of the Environment (MDE) in support of the MD iMap initiative (One State-One Map). It highlights the efforts being undertaken by the State and county and municipal stormwater management programs to control urban water pollution. The aim is to provide planners, government authorities, and the public with critical data and analyses that will help with decision-making and provide public outreach. In the first phase, StormwaterPrint will present the following:

  • Locations of various Best Management Practices (BMPs) scattered throughout Maryland, and
  • Delineated drainage area of BMPs, retrofits, and stream restoration projects required under Maryland’s NPDES Municipal Stormwater Permits. What is a Municipal Stormwater Permit?

Stormwater management is an integral component of Maryland’s environmental consciousness. The State is home to numerous streams and rivers that ultimately drain to Chesapeake Bay, the largest inland estuary in the United States. These streams and the Bay not only provide drinking water, food, economic opportunities, and water for irrigation, but also a home for a diverse ecosystem.

Hydrologic Cycle, before and after development However, growing population and land use changes associated with urbanization modify the hydrology of receiving surface waters and deteriorate stream health. Impervious area, such as building rooftops, paved streets, and parking lots added as a consequence of new and past development results in changes to how rainfall and subsequent runoff occurs. These include increases in peak flow and total volume of stormwater runoff and accelerated stream channel erosion. Excess sediments, nutrients, chemical contaminants, and other pollutants build stress on flora and fauna and contribute to decline in water quality. Additionally, accidental spills, illegal dumping, and sanitary sewer system leaks can also cause significant degradation. So, managing urban runoff has become increasingly important.

Stream RestorationTraditionally, stormwater management for new development and redevelopment in Maryland has been provided by use of Urban Best Management Practices or BMPs. BMPs are generally of two types – structural and nonstructural. Structural practices are physical devices designed and constructed to trap the pollutants from runoff. Nonstructural methods focus on preserving open space and incorporating existing landscape features into a site plan to manage stormwater at its source.Click here for a list of various BMPs. In areas of old development that did not have stormwater management (i.e. Pre-1985 construction), stormwater retrofits are done. Mitigation may also be provided by stream restoration projects.

Click here or on image below to view a slideshow on the Maryland Stormwater Program.