What is Stormwater & How do we Manage it?

What is Stormwater?

Stormwater can be defined as precipitation, such as rain, snow, and sleet. Only a tiny percentage of stormwater becomes surface runoff in a natural setting. However, as development takes place, this percentage grows. This runoff flows into the nearest stream or creek, river, lake, or wetland.

What is Stormwater Management?

Stormwater management is the management of this surface runoff. Land development leads to a significant increase in runoff volume and frequency. The construction of impervious surfaces such as roads, parking lots, roofs, and storm sewer pipes, which efficiently collect and discharge stormwater runoff, helps prevent rainwater infiltration. Stormwater runoff must be managed to offset the potential impacts of impervious surfaces, including decreased groundwater recharge and increased frequency of flooding. Non-point source pollution is also a significant cause of stream impairment.

This management reduces flooding damage to property and people and helps prevent polluted runoff from affecting local waterways. Impervious surfaces disrupt the natural hydrologic cycle, causing less infiltration, interception, and evapotranspiration than before any development was made. The stormwater flow rate and volume produced by impervious surfaces have increased significantly. This stormwater runoff substantially contributes to flooding, sediment deposition, erosion, non-point source pollution, and stream channel instability.

Stormwater should not be considered a resource but has benefits like groundwater recharge. This maintains streams’ flows.

Stormwater management can also help reduce the severity and frequency of flooding. Stormwater management is a traditional method that uses surface runoff to divert it to a detention pool, which stores the water and releases it over time. This allows water to be returned to the groundwater at a higher volume and more extended. However, this does not always solve the problem but may lead to another. Stormwater can be recharged into groundwater to protect it from flooding and erosion.

Stormwater Runoff: Common Source Pollution


  • The most significant pollutant load is associated with sediment
  • Stormwater runoff in urban settings The loadings are exceptional.
  • Construction activity that does not have erosion controls can cause high levels.
  • Sediment can increase turbidity and harm aquatic and benthic habitats.
  • Reduces the impoundment capacity
  • Many other pollutants attach to and are carried by the body.
  • Sediment particles. Nutrients
  • Stormwater runoff contains phosphorus, nitrogen, and other nutrients.
  • Nutrient loads in surface waters can cause heavy algae growth, especially in impoundments, and low dissolved oxygen.
  • The urban system is contaminated by runoff from fertilizers for lawns and gardens (commercial and residential), leaks from septic systems and sanitary sewers, as well as animal wastes.
  • Organic Matter
  • Stormwater may carry various forms of organic matter in urban stormwater areas-organisms decompose this material in surface water.
  • Depletes oxygen levels.
  • Water quality and life are severely affected by low levels of dissolved oxygen in surface waters
  • Organic matter can be found in leaking septic systems and garbage, yard waste


Leakage of sanitary facilities can lead to high bacterial levels in stormwater runoff.

Systems, garbage, and animal waste

  • Surface water contamination can affect aquatic life and recreational activities and pose health risks. Oil and Grease
  • Stormwater can transport oil, grease, fuels, and lubricating substances from leaks or spills.
  • The level of pollutants in the water bodies adjacent to it is affected by the intensity of urban activities such as vehicle traffic and maintenance, fueling, and manufacturing activities.

Toxic Substances

  • Metals are toxic substances that can be found in urban stormwater.
  • Pesticides, herbicides, and hydrocarbons.
  • Toxic chemicals affect biological systems and accumulate at the bottom
  • Sediments of surface waters Heavy Metals
  • Urban stormwater runoff contains metals like copper, lead, zinc, arsenic, and chromium.
  • Stormwater metals can be toxic to some aquatic species and accumulate in aquatic marine animals.
  • Stormwater can be found in automobiles, paints, and preservatives in urban areas.


  • Stormwater runoff rises in temperature when it flows over impervious surfaces
  • Water stored in shallow, unshaded ponds is another option.
  • Temperature increases when there are impoundments.
  • The tree canopy can be removed to create water bodies that absorb solar energy.


  • Higher water temperatures can impact the water body’s ability to support certain fish and other aquatic organisms are at risk due to low dissolved oxygen levels.

Local communities also benefit from stormwater management. Facilities that are properly maintained can help reduce the costs of stream channel restoration and pollution mitigation. Stormwater drop inlets and culverts can be clogged with sediment and debris from runoff. These structures can be expensive to maintain, but stormwater management can help reduce these costs.


Stormwater reduction is an effective way property owners can help their community. Homeowners and businesses can use stormwater for other purposes by capturing it or using it to capture it. There are many ways to reduce stormwater runoff.

Rain barrels can be an effective and straightforward way to reduce stormwater runoff. Rain barrels are containers that collect rooftop runoff from buildings or houses. Any stormwater that falls from a roof or gutter will be compiled into the container (for a more attractive option use a rain chain). It can then be stored until it is ready to use. Water from the rain barrel can water plants, wash windows or cars, or even fill a swimming pool.

Vegetated roofs are another option that can be used to reduce stormwater runoff from a home or building. Vegetated roofs are made up of a waterproof membrane, or liner, on top. The soil or growth medium is then placed on top. Finally, the liner is seeded with grasses and other aquatic pond plants. You can make vegetated roofs more complicated by adding insulation or a piping system. If there is a significant amount of precipitation, the piping system may be required. In this case, the piping will transport the water to another collection system. Vegetative roofs enable vegetation to use the rainwater and reduce or eliminate stormwater from the shelter.


Stormwater runoff can be reduced by using best practices in restoration. Reclamation of disturbed sites to create natural landscapes is one example of best practices in stormwater management. These best practices include the use of riparian buffers and proper forest management.

Riparian buffers can be found around bodies of water or near them that act as buffers and cushions. Development may reach the edges of streams, rivers, or lakes in certain areas. Stormwater runoff directly into the waterway is causing this development to impact it. To provide a buffer for the waterwaywatercourse, riparian buffers can be restored to filter pollutants from stormwater before they reach the waterway channel. Riparian buffers can also stabilize streams and lakeshores and reduce erosion potential.

Planning and implementation are essential to good forest and land management practices that reduce stormwater runoff. Sometimes clearing a forest is necessary to accomplish specific goals. However, stormwater runoff increases from areas where the vegetation has been cleared. Stormwater runoff can be reduced or minimized using best practices like silt fencing and soil berms. Barren areas should be planted with vegetation that can grow in the current landscape conditions. The more vegetation established, the more significant the stormwater runoff reduction.