Stormwater management is the planning and control of runoff from rainfall or snowmelt at a site or across a drainage area.
Definition
Stormwater management addresses how runoff is collected, conveyed, stored, infiltrated, treated, or otherwise controlled. A project may combine grading, pipes, channels, detention, retention, green infrastructure, and operating or maintenance requirements. What is included depends on site conditions, the client's goals, permits, and local criteria. Firms may focus on peak flow, drainage, water quality, erosion, or several objectives, and the scope should identify which are covered. Calculations and designs use project data and assumptions; requirements and accepted practices vary among jurisdictions. Stormwater management is an overall planning and design effort, not one specific facility or a guarantee that flooding or water quality impacts will never occur. Long-term operation can also depend on ownership, maintenance, and performance of installed features. EPA stormwater resources offer context on stormwater permits and controls.
How owners use it
- Coordinate drainage, runoff control, water quality, and site layout decisions.
- A site generates 9 acre-feet of modeled runoff and a proposed measure stores 3, leaving 9 - 3 = 6 acre-feet for other routing or controls.
- Identify which stormwater objectives and criteria are included in a project's scope.
- Clarify who is responsible for maintaining stormwater facilities after construction.
