stormwater management runoff

Stormwater Management: Why It’s Important

by McKenzi Heger | December 10, 2018

The importance of an effective stormwater management system is imperative to your safety and the health of the environment. We recently announced a 20-year contract with the City of Annapolis, so the local benefits of a stormwater management system have been at the top of our mind, especially given the greater frequency of rain we’ve received and the potential for a winter full of snow.

stormwater management runoffWhat is stormwater management?
Stormwater comes from any precipitation falling from the sky including rain, sleet, or melting snow and can be effectively managed through stormwater management by companies like GreenVest. As more land is developed, we also see a change in the natural patterns and rates of runoff Mother Nature has created. Construction of buildings, parking lots and roadways, however, alters the volume and velocity of natural runoff, leaving a significant need to properly convey our stormwater safely to its final destination (i.e. its designated body of water).

Why is stormwater management so important?
When we build roads, buildings and other structures, the natural infiltration of runoff is interrupted, resulting in increased rates of runoff and localized flooding. Increased levels of impervious surface area add pollution to streams, rivers, and creeks and ultimately larger water bodies like the Chesapeake. Decreased infiltration and increased runoff create the need for stormwater management, which provides significant benefit to people (health, welfare, and safety) and the environment (health, function, and sustainability).

Traditional stormwater management includes detention ponds that dotted our communities. These ponds detain stormwater runoff, holding it or slowly releasing it over time to the nearest water body. While this may seem like a solid plan to manage stormwater, it has its shortcomings. Traditional ponds were not sized to handle what is now considered a minimum “water quality” storm event, let alone providing detention for larger storm events and many were not designed to provide groundwater infiltration –  thus not solving the root of the problem. There are three key components that are considered in contemporary stormwater management design:

  1. Effective treatment of water quality
  2. Control of excess runoff volume and velocity
  3. Groundwater infiltration

Controlling the volume and velocity of stormwater provides important functions to people including flood risk management and storm damage prevention.  Furthermore, groundwater recharge is an important part of stormwater management as it helps maintain the base flow in nearby stream and wetlands, replenishing drinking water supplies and reducing the overall volume of runoff helping to reduce or eliminate erosion.

Perhaps one of the most important factors to consider in stormwater management is preventing pollution by supporting good water quality. This is essential to supporting both ecosystem and community health, function and resiliency. Runoff can include bacteria and organic matter from trash and animal waste, oil and grease from leaky cars on the roads, toxic chemicals like pesticides and more. Many of these pollutants carry nitrogen, phosphorous and sediment which in small amounts are beneficial to aquatic systems but in larger amounts are detrimental to system health and function.  These pollutants are harmful to our environment as they are carried by rivers, streams, and creeks and into larger bodies of water like the Chesapeake Bay.

What can be done about runoff, and who can help implement management techniques?
Federal, state and local laws govern what can be discharged into our waterbodies and how that runoff must be treated prior to discharge. These laws require permits, Federal, State and local, to repair, expand or construct new impervious surfaces. Additionally, permits are required when companies, like GreenVest, implement effective stormwater management practices or programs. For example, GreenVest is helping the City of Annapolis comply with its Municipal Separate Storm Sewer (MS4) Permit throughout the life of our contract. This MS4 compliance program will help address water quality, stormwater volume, and velocity and where possible promote groundwater recharge. This program will provide significant benefit to local residents as well as the health and function of water local bodies.

In order for us to thrive, we must first take care of our environment. As we protect our water resources and ecosystems with effective stormwater management, we invest in our future. Learn more about our past stormwater management projects.

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