What is stormwater runoff?
Stormwater runoff is water from rain or melting snow that "runs off" across the land instead of seeping into the ground. This runoff usually flows into the nearest stream, creek, river, lake or ocean. The runoff is not treated in any way.
What is polluted runoff?
Water from rain and melting snow either seeps into the ground or "runs off" to lower areas, making its way into streams, lakes and other water bodies. On its way, runoff water can pick up and carry many substances that pollute water.
Some – like pesticides, fertilizers, oil and soap – are harmful in any quantity. Others – like sediment from construction, bare soil, or agricultural land; or pet waste, grass clippings and leaves – can harm creeks, rivers and lakes in sufficient quantities.
In addition to rain and snowmelt, various human activities like watering, car washing, and malfunctioning septic tanks can also put water onto the land surface. Here, it can also create runoff that carries pollutants to creeks, rivers and lakes.
Polluted runoff generally happens anywhere people use or alter the land. For example, in developed areas, none of the water that falls on hard surfaces like roofs, driveways, parking lots or roads can seep into the ground. These impervious surfaces create large amounts of runoff that picks up pollutants. The runoff flows from gutters and storm drains to streams. Runoff not only pollutes but erodes streambanks. The mix of pollution and eroded dirt muddies the water and causes problems downstream.
What causes polluted stormwater runoff?
Polluted stormwater runoff generally happens anywhere people use or alter the land. People going about their daily lives are the number one source of stormwater pollutants. Most people are unaware of how they impact water quality. Some common examples include over fertilizing lawns, excessive pesticide use, not picking up pet waste, using salt or fertilizer to de-ice driveways, letting oil drip out of their vehicles and littering. Developed areas in general, with their increased runoff, concentrated numbers of people and animals, construction and other activities, are a major contributor to pollution, as are agricultural activities. Other contributors include forest harvesting activities, roadways, and malfunctioning septic systems.
Why do we need to manage stormwater and polluted runoff?
Polluted stormwater runoff is the number one cause of water pollution in Georgia.
Polluted water creates numerous costs to the public and wildlife. As the saying goes, "we all live downstream." Communities that use surface water for their drinking supply must pay much more to clean up polluted water than clean water.
Polluted water hurts wildlife in creeks, streams, rivers and lakes. Dirt from erosion, also called sediment, covers up fish habitats and fertilizers can cause too much algae to grow, which also hurts wildlife by using up the oxygen they need to survive. Soaps hurt fish gills and fish skin, and other chemicals damage plants and animals when they enter the water.
The quantity of stormwater is also a problem. When stormwater falls on hard surfaces like roads, roofs, driveways and parking lots, it cannot seep into the ground, so it runs off to lower areas. To give you an idea of the difference a hard surface makes, consider the difference between one inch of rain falling onto a meadow and a parking lot. The parking lot sheds 16 times the amount of water that a meadow does!
Because more water runs off hard surfaces, developed areas can experience local flooding. The high volume of water also causes streams banks to erode and washes the wildlife that live there downstream.
How are stormwater and runoff "managed"?
"Best management practices" is a term used to describe different ways to keep pollutants out of runoff and to slow down high volumes of runoff.
Preventing pollution from entering water is much more affordable than cleaning polluted water! Educating state residents about how to prevent pollution from entering waterways is one best management practice. Laws that require people and businesses involved in earth disturbing activities – like construction and agriculture – to take steps to prevent erosion are another way to prevent stormwater pollution. There are also laws about litter, cleaning up after pets and dumping oil or other substances into storm drains.
Education and laws are just two best management practice examples. Some BMPs are constructed to protect a certain area. Some are designed to slow down stormwater, others help reduce the pollutants already in it – there are also BMPs that do both of these things.
Detention ponds, built to temporarily hold water so it seeps away slowly, fill up quickly after a rainstorm and allow solids like sediment and litter to settle at the pond bottom. Then, they release the water slowly. These ponds are one constructed BMP example. Green roofs, storm drain grates, filter strips, sediment fences and permeable paving are other examples.
What are the legal requirements for managing stormwater?
The federal Clean Water Act requires large and medium sized cities to take the following steps to reduce polluted stormwater runoff:
- Conduct outreach and education about polluted stormwater runoff.
- Provide opportunities for residents to participate and be involved in conversations and activities related to reducing polluted stormwater runoff.
- Detect illicit discharges (e.g. straight piping or dumping).
- Control construction site runoff.
- Control post-construction runoff.
- Perform municipal housekeeping (e.g. take steps to prevent runoff from city buildings and activities.)
- What can I do to reduce the amount of stormwater pollution I contribute?
- If you own a car, maintain it so it does not leak oil or other fluids. Be sure to wash it on the grass or at a car wash so the dirt and soap do not flow down the driveway and into the nearest storm drain.
If you own a yard, do not over fertilize your grass. Never apply fertilizers or pesticides before a heavy rain. If fertilizer falls onto driveways or sidewalks, sweep it up instead of hosing it away. Mulch leaves and grass clippings and place leaves in the yard at the curb, not in the street. Doing this keeps leaves out of the gutter, where they can wash into the nearest storm drain. Turn your gutter downspouts away from hard surfaces, seed bare spots in your yard to avoid erosion and consider building a rain garden in low-lying areas of your lawn.
Pet owners should pick up after their pets and dispose of pet waste in the garbage.
Keep lawn and household chemicals tightly sealed and in a place where rain cannot reach them. Dispose of old or unwanted chemicals at household hazardous waste collections sites or events.
Never put anything in a storm drain. Don't litter.
How else can I help reduce stormwater pollution in my area?
Participate in the next stream or river cleanup in your area. Storm drain marking events – where the destination of storm water is clearly marked on the drain – are a fun way to let your neighbors know the storm drain is only for rain.
Attend public hearings or meetings
on the topic so you can express your concerns.
Report stormwater violations when you spot them to Community Development at 678-512-3200
Why does the City have a Stormwater Management Program (SWMP)?
The City has developed and implemented a SWMP to maintain and enhance water quality and ensure that negative stormwater impacts are minimized throughout the City. The SWMP consists of both citizen educational efforts as well as technical and regulatory programs. It is also a federal and state requirement that certain cities and counties implement a SWMP.
What federal and state laws require the City to have a SWMP?
The federal Clean Water Act requires Georgia (and most other states) to comply with the National Pollutant Discharge Elimination System (NPDES). To comply with this program, the Georgia Environmental Protection Division requires local governments to obtain NPDES permit coverage by developing and implementing a SWMP.
What is the City's SWMP?
The City's SWMP consists of 6 categories and a number of practices and/or programs to address and support each category. These categories are: Public Education, Public Involvement, Illicit Discharge Detection & Elimination, Construction Site Runoff Control, Post-Construction Stormwater Management, and Pollution Prevention from Municipal Activities. Implementation of all 6 categories make up a comprehensive program.
What is the City doing for Public Education & Public Involvement?
The City's public education and involvement efforts are directed to both the development/engineering community as well as the general public. The City posts articles and stormwater-related information on the website as well provides permit applicants with detailed checklists to ensure stormwater requirements are met. The City also hosts an annual Fall Festival and Public Works Day to distribute stormwater information and inform citizens on how stormwater is addressed within the City. Other programs the City participates in are Adopt-A-Road, Stormdrain Markers, Stream Cleanups, and Bulky Trash and Recycling Day.
What is the City doing for Illicit Discharge Detection & Elimination?
An illicit discharge is a discharge of pollutants or non-stormwater materials such as sanitary wastes, yard debris and auto fluids, into a stormwater drainage system. The City adopted an Illicit Discharge and Illegal Connection Ordinance in 2006 that establishes fines for illegal discharges. In addition, the City inspects stormwater outfalls annually to ensure non-stormwater discharges are identified and corrected. The City also posts information on the website and has an active stormdrain marking program that educates the public about the stormwater system, pollutants, and illicit discharges.
What is the City doing for Construction Site Runoff Control?
The City has an erosion & sediment control ordinance and requires compliance with approved erosion & sediment control plans for building and land disturbance permits. City inspectors visit these permitted sites to ensure the plan is being followed and sediment is retained onsite and prevented from adjacent properties and surface waters. The City also enforces stream buffers which prevents development activities from occurring close to streams.
What is the City doing for Post-Construction Stormwater Management?
The City has adopted a stormwater ordinance and design manual to ensure that water quality is maintained and improved and drainage systems are designed to protect downstream properties. The ordinance requires that new developments and redevelopments have a plan in place to address quality and quantity impacts. The design manual provides guidance on the proper ways to select, design and maintain stormwater controls.
What is the City doing for Pollution Prevention?
The City has programs to inspect and maintain storm structures in the rights of way. Structures such as catch basins and inlets are cleaned and the roadways are swept to keep trash and debris from entering the storm system. In addition, the City conducts annual water quality training sessions for employees and retrofits existing, City-owned detention ponds so that they better able to reduce pollutants and enhance water quality.
How can I learn more?
To learn more about the City's stormwater management program, please visit our Stormwater Management