February 1, 2010 - Maryland Stormwater Management Update

Environmental Site Design (ESD) is defined as a storm water management approach that uses: 1) small-scale storm water management practices; 2) nonstructural techniques; and, 3) better site planning to mimic natural hydrological runoff characteristics and minimize the impact of land development on water resources.

Complying with the directive to put into practice ESD to the “maximum extent practicable” requires significant changes to the way storm water management for new development and redevelopment projects are conceptualized, designed, reviewed, and constructed in Maryland.

In the case of plans that have not been approved by May 4, 2010, or plans already approved but not diligently pursuing construction, there currently is no “grandfathering” provision under the new standards. All plans not approved by May 4th will be required to provide ESD. This compliance will have several impacts on plans, including but not limited to increased costs and/or decreased density.

VIKA analyzed the impact of the new regulations on seven (7) previously designed projects that were designed using Maryland’s 2000 Storm Water Management regulations. Our review included projects that ranged from low impervious coverage (below 50%) to dense urban projects (impervious coverage exceeding 75%).

In most cases, VIKA found that the cost of implementing ESD measures or ESD to the maximum extent practicable, or alternatively implementing structural measures for both new development and re-development, is significantly more and/or has resulted in loss of density from previous designs. This increase in cost ranged from several thousand dollars to millions of dollars. It is likely this cost increase will force developers to expand the overall footprint of the development, working at cross purposes for Smart Growth.

ESD tools include: restoring natural area remnants; pollution prevention practices; compost-amended soils; impervious cover removal; permeable pavers; green roofs and cisterns; foundation planters; expanded tree pits; street bio-retention; underground filters; reforestation/restoration of stream corridor; and, storm water retrofits.

To view a copy of our testimony before the State’s Task Force on Future Growth and Development in Maryland, which includes this comparative analysis, please click here (9.8MB download).