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StormwaterPrint: Measuring Success

Stormwater Management by Era

Table 1.  Urban areas developed in different eras in Maryland

Era Area (acres)
Total Urban 1,371,020 100%
Pre-1985 979,922 69%
Between 1985-2002 243,513 15%
Between 2002-2010 147,585 11%
Retrofits 65,212 5%

Stormwater management program in Maryland can be divided into four significant eras as follows (also shown in Table 1):

Pre-1985: Development until 1985 had no significant stormwater management. Detrimental effects of this urbanization on the waters of the State led to the passing of Maryland’s original stormwater management act in 1982 by the General Assembly. State regulations were adopted in 1983 and local ordinances were completed by 1985.

1985 to 2002: Local programs, criteria, and associated BMPs to address the 1982 law were implemented in this period. The statewide stormwater management program focused primarily on flood control but established an ‘order of preferences’ for selecting water quality BMPs such as infiltration, attenuation, retention, and extended detention.

2002 to 2010: The State’s stormwater management program was modified in 2000 with the implementation of the 2000 Maryland Stormwater Design Manual. The Manual required that a ‘unified sizing criteria’ be used to address groundwater recharge, water quality, and channel protection. Local governments implemented the Manual by 2002.

Stormwater Management Eras Post-2010: The Stormwater Management Act of 2007 was passed in April of that year and it requires the use of environmental site design (ESD) to the maximum extent practicable (MEP). Counties and municipalities started adopting the new law in 2010.

Maryland's NPDES municipal stormwater permits require larger localities to retrofit the urban areas with little or no stormwater management. So far 65,212 acres have been restored across the State through stormwater management implementation, accounting for 5% of the total acres developed.Click here for more information...

Two-year Nutrient Reduction Milestones

The Chesapeake Bay Program set an overall ‘general’ pollution reduction goal for restoring the Bay by 2025. However, despite successes, it was not clear if the results were sufficient to meet these long-term goals of the future. To increase accountability and accelerate and measure progress, former Maryland Governor Martin O’Malley announced “Two-year Milestones” to put Maryland on track to meet nutrient reduction goals by 2020. BayStat process was used to develop milestones and the first set of the two-year milestones will be completed in December 2011, followed by next milestone for 2013 and so on.

Read the 2011 Milestones document.
Read more about BayStat...

Watershed Implementation Plans

Another major program has been the introduction of Maryland’s Draft Phase I Watershed Implementation Plan (WIP) for the Chesapeake Bay Total Maximum Daily Load (TMDL) in December 2010. The WIP is the cornerstone of the accountability framework for restoring the Bay. It will serve as a roadmap for how and when the State plans to meet its pollutant allocations under the TMDL to meet Bay water quality standards. Maryland’s WIP provides a series of proposed strategies that will collectively exceed the 2017 target (70% of the total reductions needed to meet Maryland’s accelerated deadline of 2020). Click here for more information...



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