In the 1990s, the EPA amended the United States Clean Water Act to address a growing problem – the lack of proper stormwater management planning.
“Why does stormwater matter?” you may be thinking.
Well, did you know that in the 1970s two-thirds of this country’s waters were unsafe for fishing and swimming?
Stormwater runoff was one of the main sources of this pollution.
This is why the Clean Water Act requires many municipalities to create a stormwater management plan.
It ensures that debris, pollutants and chemicals from storm sewers and construction sites do not find their way to the nation’s waters.
And, if you plan to construct a building, you may need to comply with these plans.
Keep reading to learn more!
1. What is a stormwater management plan?
A stormwater management plan is a plan that helps to reduce pollution and contamination by controlling runoff of rainwater or melted snow.
There are two different kinds of stormwater plans:
Stormwater Pollution Prevention Plans (SWPPP): this is a temporary plan designed to mitigate any stormwater issues created by a construction project.
Stormwater Management Plan (SWMP): this kind of plan is created by a variety of entities, most notably municipalities that have a municipal separate storm sewer system (rather than a combined sewer and stormwater system).
This blog will primarily focus on Stormwater Management Plans.
2. Why is it critical to manage stormwater?
Developing the land disrupts nature.
This disruption affects stormwater rates when it limits and impedes the natural flow of the water and the ground’s ability to soak it up.
Additionally, as this occurs, water runoff becomes contaminated.
As the water rolls over any impermeable surfaces (i.e., rooftops, sidewalks, etc.), harsh chemicals in these locations end up polluting the water.
If and when these chemicals reach local natural water bodies, they can harm and potentially kill any plant or wildlife nearby.
Furthermore, humans end up at risk because these water bodies can be sources of drinking water.
Now, you may think, “How common is this really?”
Even the smallest storm can create water runoff problems, which is why managing stormwater runoff is essential through a stormwater management plan.
3. What are the main problems that stormwater runoff can create?
The top problems created by stormwater runoff include:
Pollution occurs when water flows over an impervious surface and collects the chemicals on top of it.
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.
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.
Stormwater runoff can overflow drainage ditches, sewage systems, and storm drains unless proper management is in place.
This flooding can be inconvenient if not dangerous.
Even if water finds land that can absorb it, it may increase sedimentation.
This is called turbidity, or muddiness, which ruins nearby land.
All of the above (flooding, erosion, pollution, and turbidity) can wreak havoc on the local infrastructure.
4. What are the goals of a stormwater management plan?
The goals of a stormwater management plan include:
Reducing flood damage (including damage to life and property)
Minimizing any increase in stormwater runoff from new development
Reducing soil erosion from development or construction projects
Assuring the adequacy of existing and proposed culverts, bridges, and other in-stream structures
Maintaining groundwater recharge
Preventing an increase in nonpoint pollution
Maintaining the integrity of stream channels for their biological functions as well as for drainage
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
Minimizing pollutants in stormwater runoff from new and existing developments to protect public safety through the proper design and operation of stormwater basins
5. 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, it’s estimated that over 40 percent of existing water pollution problems are attributable to nonpoint source pollution.
6. Who must create a stormwater management plan?
Municipalities must apply for a permit under the EPA’s National Pollutant Discharge Elimination System (NPDES) if they have a separate storm sewer system (MS4).
This is a stormwater collection system that is separate from the municipal sewer system.
In order to obtain an NPDES permit, the municipality must draft a stormwater management plan.
7. What is included in a municipality’s stormwater management program and plan?
The stormwater management plan should outline a program with the following elements:
Public education and outreach
Public participation and involvement
Illicit discharge detection and elimination
Construction site runoff control
Post-construction runoff control
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 water bodies.
In addition, the stormwater management plan for the program should also be clear about the following:
What needs to happen
Who needs to do it
How much they need to do
When they need to get it done
Where it is to be done
8. How does my municipality’s stormwater management plan affect me?
As part of their 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 you need to do is tap into it.
However, these systems can only handle so much, and thus having an excess of water runoff in these systems can lead to flooding or damage to the infrastructure.
This means that you may be required to keep as much storm runoff on-site as possible.
Fortunately, there are many on-site stormwater control measures, including:
Bioretention Areas/Rain Gardens
Curb and Gutter Elimination
Rain Barrels and Cisterns
Sand and Organic Filters
Vegetated Filter Strips
Vegetated Swales/Dry Swales
Which system you choose to implement will ultimately depend on your project and location.
Your local county or city will have certain requirements, and you’ll need to cater your project to the guidelines provided.
9. What are the pros and cons of managing stormwater on-site?
Managing surface runoff on-site is largely beneficial, but it does require planning and thought.
Here are the pros and cons.
Proper drainage of surface run-off
Ability to recharge groundwater and reuse precipitation water and surface run-off as irrigation or household water
Treatment of stormwater in a very early stage
Avoids damage to infrastructure (private properties, streets, etc.)
Can be integrated into the urban landscape and provide green recreational areas
Expert planning, implementation, operation, and maintenance required
A lot of operation and labor required depending on the technique
Risk of clogged infrastructure caused by high sedimentation rates
10. How does my municipality fund its stormwater management plan?
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 (i.e. stormwater+sewer) overflow controls.
Generally speaking, there are two categories of funding that municipalities can obtain.
The first is capital funding and the other is annual funding.
Capital funding includes bonds, loans, grants, privatization, and any other capital funding options like special reserves and assessments.
Annual funding includes fees, taxes, and miscellaneous funds like proffers and capacity credits.
11. How can I get involved?
Municipalities often involve the public during the planning process of their stormwater management programs.
So, keep an eye on whether your municipality is hosting public meetings to discuss its stormwater management program.
In addition, the EPA encourages wider community outreach by suggesting your municipality:
Identify key users and groups
Establish an advisory committee
Create a stormwater utility website
Prepare pamphlets and presentations
Meet with key user groups and the media