With little fanfare, legislation sailed through the General Assembly this year that could revolutionize Maryland's approach to reducing the rainwater runoff that is so poisonous to the Chesapeake Bay.
Developers throughout the state will be required to design and construct their projects in a way that retains as much as possible of the natural groundcover, allowing rainwater to soak into the soil instead of washing off hard surfaces, carrying sediment and pollutants into the nearest waterway.
The effectiveness of the new law will depend mightily, though, on how tightly state officials draw the regulations that put it into effect, and how faithfully county and municipal governments update their zoning ordinances to comply with those rules.
Gov. Martin O'Malley, whose administration strongly supported the measure, will have to take care that it doesn't get weakened through compromises made during the regulatory process.
The goal of the new law is to officially discredit old thinking on stormwater management. Initially, the water was swept away in pipes and culverts, eroding streams and speeding nitrogen and phosphorus into the bay, where it feeds algae that choke the water of oxygen. That approach was replaced in more recent years by the use of retention ponds, which proved ineffective at trapping sediment and required frequent maintenance.
Environmental planners now advocate that development tracts be kept as close as possible to their natural state. Clearing and grading should be minimized. Building sites should be confined to small footprints and located to preserve trees and other foliage. Driveways should be made of material water can soak through, and be short or even shared.
After the state Department of Environment writes the regulations requiring use of such techniques, local zoning laws will have to be changed to eliminate outdated requirements, such as for sidewalks and curbs, that run counter to the more natural approach by adding impervious surfaces.
If this sounds like a major departure from past practice, it is. Some advocates suspect resistance to the measure was muted during the General Assembly session because opponents calculate they can simply water down the rules.
That can't be allowed to happen. Maryland has an enormous backlog of eroded streams and ruined waterways that must be repaired if the bay is ever to be nursed back to health. New development, at least, should be designed to be as environmentally friendly as it can reasonably be made.