Better Site Design (BSD), in the context of stormwater management, refers to a suite of planning, design, and development strategies that reduce the hydrologic and environmental impacts of land development by preserving natural site features, minimizing impervious cover, and integrating stormwater controls into the built environment. BSD is both a philosophy and a practical framework that seeks to maintain pre-development runoff characteristics as closely as possible, thereby reducing runoff volume, peak discharge rates, pollutant loads, and downstream channel erosion.
At its core, Better Site Design emphasizes working with the natural landscape rather than against it. Traditional development patterns often prioritize maximizing buildable area, which leads to extensive clearing, grading, and paving. In contrast, BSD promotes site layouts that conserve existing vegetation, natural drainage patterns, soils, and topography. By doing so, it preserves the site’s inherent capacity for infiltration, evapotranspiration, and pollutant filtering, all of which are critical to maintaining watershed health.
A key principle of Better Site Design is the reduction of impervious cover, such as roads, rooftops, and parking areas. Impervious surfaces prevent water from infiltrating into the ground, increasing both the volume and velocity of stormwater runoff. BSD techniques address this by narrowing street widths, reducing parking requirements, using permeable pavement where appropriate, and encouraging clustered or compact development patterns. These approaches not only reduce runoff but also decrease infrastructure costs and land disturbance.
Another major component of BSD is the conservation of natural areas, including forests, wetlands, floodplains, and riparian buffers. These features act as natural stormwater management systems by slowing runoff, promoting infiltration, and filtering pollutants. Preserving them within a development site helps maintain ecological functions and provides additional benefits such as habitat protection, temperature regulation of streams, and improved aesthetics.
Better Site Design also incorporates distributed stormwater management practices, often referred to as low-impact development (LID) or green infrastructure. Rather than relying solely on large, centralized facilities like detention basins, BSD encourages smaller, decentralized practices such as bioretention areas, vegetated swales, infiltration trenches, and rain gardens. These practices manage runoff closer to its source, improving water quality and mimicking natural hydrology.
From a regulatory and planning standpoint, BSD is frequently embedded in local ordinances, zoning codes, and design manuals. Many jurisdictions encourage or require BSD techniques as part of stormwater permits, particularly under programs related to municipal separate storm sewer systems (MS4s). It is also commonly associated with guidance from organizations such as the Center for Watershed Protection, which has been instrumental in developing BSD principles and promoting their adoption nationwide.
Better Site Design is a comprehensive approach to land development that integrates site planning, engineering, and environmental stewardship to minimize stormwater impacts. By reducing impervious surfaces, preserving natural features, and employing decentralized management practices, BSD helps protect water quality, reduce flooding and erosion, and create more sustainable and resilient built environments.