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Stormwater Management Planning: Does it
Stormwater Management Planning: Does it Matter?
Erica Benson
In the 1990s, the U.S. Environmental Protection Agency (EPA) amended the Clean Water Act to address a growing problem—the lack of proper stormwater management planning.
“Why does stormwater planning matter?” you may be thinking. Well, did you know that in the 1970s two-thirds of the waters in the United States were unsafe for fishing and swimming?
Stormwater runoff was one of the main sources of this pollution, which is why the Clean Water Act requires many municipalities to create a stormwater management plan to ensure that debris, pollutants, and chemicals from storm sewers and construction sites do not find their way to the nation’s waters.
What is a Stormwater Management Plan?
A stormwater management plan helps to reduce pollution and contamination by controlling runoff of rainwater or melted snow.
There are two different kinds of stormwater plans: S Stormwater Pollution Prevention Plan. This is a temporary plan designed to mitigate any stormwater issues created by a construction project. S Stormwater Management Plan. This kind of plan is created by a variety of entities, most notably, municipalities that have a municipal separate storm sewer system (MS4), rather than a combined sewer and stormwater system.
This article will primarily focus on stormwater management plans.
Why is it Critical to Manage Stormwater?
Developing the land disrupts nature. This disruption affects stormwater when it limits and impedes the natural flow of water and the ground’s ability to soak it up. Additionally, as this occurs, water runoff becomes contaminated.
As water rolls over any impermeable surfaces (e.g., rooftops, roads, sidewalks, etc.), harsh chemicals in these locations can pollute the water. If and when these chemicals reach local natural waterbodies, they can harm and potentially kill any plants or wildlife nearby.
Furthermore, humans can also end up at risk because these waterbodies can be sources of drinking water. Even the smallest storm can create water runoff problems, which is why managing runoff is essential through a stormwater management plan.
What Are the Main Problems That Stormwater Runoff Can Create?
The top problems created by stormwater runoff include:
Pollution
Pollution occurs when water flows over impervious surfaces and collects the chemicals on top of them. Because developed areas host countless harmful substances, they can cause severe damage if they enter a natural body of water. When this occurs, ecosystems suffer and drinking water is contaminated.
Erosion
Water flows off impervious surfaces and forms new paths. Whenever water moves over land it never has before, it can cause deterioration. This may also be detrimental to both ecosystems and local communities.
Flooding
Stormwater runoff can overflow drainage ditches, sewage systems, and storm drains unless there is proper management in place. This flooding can be inconvenient—if not dangerous.
Turbidity
Even if water finds land that can absorb it, it may increase sedimentation. This is called turbidity, or muddiness, which ruins nearby land.
Infrastructure Damage
All of the issues mentioned (flooding, erosion, pollution, and turbidity) can wreak havoc on the local infrastructure.
The goals of a stormwater management plan include: S Reducing flood damage (including damage to life and property). S Minimizing any increase in stormwater runoff from new development. S Reducing soil erosion from development or construction projects. S Assuring the adequacy of existing and
proposed culverts, bridges, and other instream structures. S Maintaining groundwater recharge. S Preventing an increase in nonpoint pollution. S Maintaining the integrity of stream channels for their biological functions, as well as for drainage. S Minimizing pollutants in stormwater runoff from new and existing developments to restore, enhance, and maintain the chemical, physical, and biological integrity of the waters of the state. This protects public health, safeguards fish and aquatic life, and maintains scenic and ecological values, which enhances the domestic, municipal, recreational, industrial, and other uses of water. S Minimizing pollutants in stormwater runoff from new and existing developments to protect public safety through the proper design and operation of stormwater basins.
How Does Stormwater Runoff Affect Us?
Stormwater runoff is one of the largest remaining major sources of pollutants in our nation’s waters. In fact, according to EPA, it’s estimated that over 40 percent of existing water pollution problems are attributable to nonpoint source pollution.
Who Must Create a Stormwater Management Plan?
Municipalities must apply for a permit under the EPA National Pollutant Discharge Elimination System (NPDES) if they have an MS4. In order to obtain an NPDES permit, the municipality must draft a stormwater management plan.
What’s Included in a Municipality’s Stormwater Management Program and Plan?
The stormwater management plan should outline a program with the following elements: S Public education and outreach S Public participation and involvement S Illicit discharge detection and elimination S Construction site runoff control S Postconstruction runoff control S Pollution prevention and good housekeeping
When these elements are implemented in concert, they are expected to produce a significant reduction of pollutants discharged into receiving waterbodies. In addition, the stormwater management plan for the program should also be clear about the following: S What needs to happen S Who needs to do it S How much they need to do S Where it’s to be done S When they need to get it done
How Does a Stormwater Management Plan Affect a Municipality?
As part of a stormwater management program, municipalities will often have regulations on new development. Some developers mistakenly believe that, because there is already a municipal storm sewer in place, all they need to do is tap into it. These systems, however, can only handle so much, and having an excess of water runoff can lead to flooding or damage to the infrastructure. This means that a municipality may be required to keep as much storm runoff onsite as possible.
Fortunately, there are many onsite stormwater control measures, including: S Bioretention areas/rain gardens Continued on page 52
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Continued from page 51 S Constructed wetlands S Curb and gutter elimination S Drainage ditches S Permeable pavements S Rain barrels and cisterns S Riparian buffers S Sand and organic filters S Vegetated filter strips S Vegetated swales/dry swales
Which of these systems to implement will ultimately depend on the project and location. The local county or city will have certain requirements, and a project will need to cater to the guidelines provided.
What Are the Pros and Cons of Managing Stormwater Onsite?
Managing surface runoff onsite is largely beneficial, but it does require planning and thought. Here are some pros and cons.
Pros
S Proper drainage of surface runoff S Ability to recharge groundwater and reuse precipitation water and surface runoff as irrigation or household water S Treatment of stormwater in a very early stage S Avoid damage to infrastructure (private properties, streets, etc.) S Flood prevention S Can be integrated into the urban landscape and provide green recreational areas
Cons
S Expert planning, implementation, operation, and maintenance required S A lot of operation and labor required depending on the technique S Risk of clogged infrastructure caused by high sedimentation rates
Obtaining funding for a stormwater management plan is one of the most crucial steps in the stormwater management process. The EPA notes that finding the lowest-cost funding methods can be challenging for municipalities.
As such, permittees often rely on local revenue bonds or State Revolving Funds for capital to fund combined sewer overflow (i.e., stormwater and sewer) controls.
Generally speaking, there are two categories of funding that municipalities can obtain. The first is capital funding and the other is annual funding. S Capital Funding. This includes bonds, loans, grants, privatization, and any other capital funding options, like special reserves and assessments. S Annual Funding. This includes fees, taxes, and miscellaneous funds, like proffers and capacity credits.
How to Get Others Involved
Municipalities often involve the public during the planning process of their stormwater management programs, so organizations can host public meetings to discuss them. In addition, EPA encourages wider community outreach by suggesting a municipality do the following: S Identify key users and groups S Establish an advisory committee S Create a stormwater utility website S Prepare pamphlets and presentations S Meet with key user groups and the media S Distribute information before initial billing
What Type of Reporting and Documentation Will a Municipality be Required to Undertake?
The type of reporting that a municipality does on its stormwater management plan will depend on several factors. At a high level, many municipalities will generate reports on the following items: S Compliance with the NPDES permit S The effectiveness of the stormwater management project S The chemical, physical, and biological impacts to receiving waters resulting from stormwater discharges S Stormwater discharges S Sources of specific pollutants S Long-term trends in receiving water quality
Plans Do Matter!
A stormwater management plan is a detailed document that includes all of a municipality’s efforts to mitigate the impact of stormwater. While time-consuming, these plans can help to drastically reduce the impact of stormwater on the environment and protect local land, wildlife, and residents.
Erika Benson is a land investor and cofounder of Gokce Capital LLC in New York City. S
