Stormwater Runoff Explained
Learn what stormwater runoff is, why hard surfaces increase runoff, and how drainage systems move rainwater away from streets and buildings.
Stormwater articles
Browse plain-English guides to stormwater runoff, drainage infrastructure, flood control, water quality, green infrastructure, maintenance, and planning.
Impervious Surfaces and Runoff Explained
Understand how roofs, pavement, compacted ground, and other impervious surfaces change the way rainwater moves through a site or watershed.
Storm Sewers Explained
A plain-English guide to storm sewers, catch basins, pipes, outfalls, and why stormwater systems are separate from sanitary sewers in many places.
Catch Basins and Stormwater Inlets Explained
Learn how catch basins, curb inlets, grates, sump areas, and inlet maintenance affect street drainage and stormwater system performance.
Culverts and Drainage Crossings Explained
Understand what culverts do, where they are used, and how capacity, blockage, erosion, and road washouts relate to drainage crossings.
Roadside Ditches Explained
Learn why roadside ditches matter for drainage, road stability, snowmelt, culverts, erosion, and rural or suburban stormwater management.
Detention Ponds Explained
A plain-English guide to detention ponds, temporary stormwater storage, controlled release rates, outlet structures, and maintenance needs.
Retention Ponds Explained
Learn how retention ponds differ from detention ponds and why permanent pools, water quality, storage, and maintenance matter.
Infiltration Basins Explained
Understand how infiltration basins use soil to absorb stormwater, what limits their use, and why soil testing and maintenance matter.
Bioswales Explained
Learn what bioswales are, how they slow and filter runoff, and why vegetation, soil media, grading, and overflow design matter.
Rain Gardens Explained
A practical stormwater guide to rain gardens, bioretention, runoff capture, soil media, plant selection, overflow, and maintenance.
Permeable Pavement Explained
Learn how permeable pavement systems can reduce runoff, where they are used, and why base layers, clogging, loading, and maintenance matter.
Green Infrastructure vs. Gray Infrastructure Explained
Compare green and gray stormwater infrastructure, including pipes, ponds, bioswales, rain gardens, storage, filtration, and hybrid systems.
Urban Flooding and Stormwater Explained
Understand why streets, underpasses, basements, parking lots, and low areas flood during storms even when a city has drainage infrastructure.
Stormwater Master Plans Explained
Learn what stormwater master plans are, what they study, and how communities use them to prioritize drainage, flooding, water quality, and infrastructure projects.
Drainage Basins and Watersheds Explained
Learn how drainage basins, catchments, watersheds, high points, low points, and downstream outlets shape stormwater problems and solutions.
Floodplain Maps and Stormwater Risk Explained
Understand what floodplain maps can and cannot tell you about stormwater risk, drainage problems, overland flow, and local flooding.
Erosion and Sediment Control Explained
Learn how stormwater can cause erosion, how sediment affects waterways and infrastructure, and why construction sites need controls.
Construction Site Stormwater Controls Explained
A guide to construction stormwater controls, temporary drainage, sediment barriers, inlet protection, stabilized entrances, and inspection responsibilities.
Stormwater Maintenance Explained
Learn why stormwater maintenance matters for ponds, inlets, culverts, ditches, swales, pipes, green infrastructure, and flood-control assets.
Combined Sewer Overflows Explained
Understand combined sewer overflows, why older systems mix stormwater and sewage, and how storage, separation, and treatment projects reduce overflow risk.
Stormwater Quality and Pollutants Explained
Learn how stormwater runoff can carry sediment, nutrients, oil residue, metals, trash, bacteria, and other pollutants into streams, rivers, lakes, and coasts.
Heavy Rainfall, Climate Change, and Stormwater Explained
A careful guide to how heavier rainfall, changing storm patterns, and aging drainage systems affect stormwater planning and infrastructure resilience.
Stormwater Fees Explained
Learn why some communities charge stormwater fees, how impervious area can affect billing, and what fees may fund.
Low Impact Development Explained
Understand low impact development, source control, distributed stormwater practices, green infrastructure, and site design that reduces runoff impacts.
Bridge Scour and Stormwater Explained
Learn how stormwater, flooding, culverts, streams, and high flows can affect bridge foundations, road crossings, and public infrastructure risk.