Stormwater is simply rain or melted snow that flows over the ground.

When precipitation lands on natural surfaces like soil, grass, or wetlands, much of it soaks into the ground. But when it falls on hard surfaces like roads, parking lots, rooftops, and driveways, it cannot soak in. Instead, it flows across the surface as runoff.

That flowing water is called stormwater.

In Nebraska communities, stormwater does not flow into a treatment plant like drinking water or wastewater. Instead, it moves through storm drains, ditches, and pipes and is released directly into local creeks, rivers, and lakes.

That means anything on the ground can be carried with it. 

Leaves, litter, fertilizer, oil, pet waste, and sediment can all be picked up by stormwater and transported into nearby waterways.

This is why stormwater matters. It is not just rain—it is a transport system connecting our streets and neighborhoods directly to our rivers.

Stormwater in Everyday Life

You see stormwater every time it rains:

• Water flowing along curbs during a storm

• Puddles forming in parking lots

• Runoff moving from lawns into the street

• Water entering storm drains at intersections

All of this water is part of the same system.

Stormwater Is Not Treated

Unlike wastewater from sinks, toilets, and showers, stormwater is not cleaned before it enters the environment.

It flows directly to local waterways. That is why keeping pollutants off the ground is one of the most important ways to protect water quality. Learn more about how stormwater differs from wastewater.

Our Water, Our Responsibility

Stormwater connects every neighborhood, street, and property in Nebraska to shared water resources. What we put on the ground today can end up in our rivers tomorrow.

Protecting water quality starts long before water reaches a storm drain—it starts where it falls.

Once rain or snowmelt becomes stormwater runoff, it has to go somewhere. In most Nebraska communities, it follows a simple path: it moves downhill, enters storm drains, travels through pipes or ditches, and is released into nearby waterways.

Unlike water that goes down a sink or toilet, stormwater is not directed to a treatment plant. Instead, it becomes part of the natural water system almost immediately after it leaves streets, parking lots, and yards. Read about a raindrop traveling through town.

The Journey of a Raindrop

A single raindrop can travel a surprisingly long way once it becomes stormwater.

It may fall on a rooftop, flow into a gutter, and then into a downspout. From there, it may enter a driveway, reach the curb, and flow into a storm drain inlet. Once inside the system, it travels through underground pipes or open channels until it reaches a ditch, creek, or river. Learn about how a raindrop travels through your back yard.

From there, that same drop can continue downstream—connecting local neighborhoods to larger waterways across Nebraska and beyond.

Local Waterways First, Larger Systems Next

In Nebraska, stormwater typically enters nearby streams, creeks, or drainage channels first. These smaller waterways eventually feed into larger rivers such as the Platte River system, and ultimately into major downstream watersheds.

This means that even small amounts of runoff from a neighborhood can contribute to water quality and flooding conditions far downstream.

Why This Matters

Because stormwater moves so quickly from streets to waterways, anything carried along with it is also transported downstream. That includes:

• Sediment from construction sites or bare soil
• Fertilizer and nutrients from lawns
• Leaves and yard waste
• Trash and litter
• Oil and vehicle fluids

Once these materials enter the system, they are difficult or impossible to remove. The EPA provides an excellent stormwater overview.

A Connected System

Stormwater systems are designed to move water away from streets efficiently to prevent flooding. But that efficiency also means everything connected to those systems is connected to local water quality.

In other words, what happens in one neighborhood does not stay in one neighborhood—it becomes part of a shared watershed.

Stormwater is more than just rainwater moving through a city. It directly affects flooding, water quality, and the health of rivers and streams that communities across Nebraska rely on. 

Because stormwater is not treated before it enters the environment, everything it carries from streets, lawns, and parking lots can end up in local waterways.

As stormwater flows over land, it can pick up pollutants such as nutrients, sediment, bacteria, and chemicals. When these materials enter creeks, rivers, and lakes, they can affect water quality in several ways:

• Excess nutrients can contribute to algae growth
• Sediment can cloud water and harm aquatic habitat
• Bacteria can affect recreation and water safety
• Chemicals can impact fish and other wildlife

Even small amounts of pollution from many properties can add up across an entire watershed. The EPA provides more on nutrient pollution.

Stormwater also plays a major role in flooding. When rain falls on natural landscapes, much of it soaks into the ground. But in developed areas, hard surfaces like roads, rooftops, and parking lots prevent infiltration.

This causes more water to run off quickly into storm systems at the same time. During heavy rainfall, this rapid flow can overwhelm drainage systems and contribute to localized flooding.

What happens in one community does not stay there. Stormwater from neighborhoods, commercial areas, and agricultural land all flows into shared waterways.

This means that local runoff can contribute to larger water quality challenges far downstream, including nutrient pollution and degraded aquatic ecosystems. Here are some stormwater pollution facts. 

Because stormwater systems collect runoff from large areas, even small actions at the individual level matter. A single yard, driveway, or street does not seem significant on its own, but together these areas make up the entire watershed. What’s on the ground is in our water.

Reducing pollution at the source is one of the most effective ways to protect water quality and reduce impacts on local waterways.

Stormwater connects every property to shared water resources. Protecting those resources depends on everyday choices—because what enters stormwater today becomes part of our rivers tomorrow.

As stormwater moves across streets, parking lots, lawns, and other surfaces, it picks up whatever it flows over or around. Because stormwater is not treated before entering local waterways, these materials are carried directly into creeks, rivers, and lakes.

Many of these pollutants come from everyday activities, which means most stormwater pollution starts at home, in neighborhoods, and in community spaces.

Pet Waste

Pet waste left on lawns, sidewalks, or parks can be washed into storm drains during rain events. This introduces bacteria and nutrients into waterways, which can affect water quality and recreational use.

Properly disposing of pet waste helps reduce this source of pollution.

Fertilizers and Yard Chemicals

Fertilizers and pesticides used on lawns and gardens can be carried away by stormwater if they are applied incorrectly or if rain occurs soon after application.

When these nutrients enter waterways, they can contribute to excessive algae growth and degrade water quality.

Grass Clippings and Leaves

Grass clippings, leaves, and other yard debris may seem natural, but when they accumulate in streets or near storm drains, they become a source of nutrient pollution.

As organic material breaks down in waterways, it consumes oxygen and can harm aquatic life.

Trash and Litter

Litter such as plastic bags, food wrappers, cigarette butts, and other debris can be transported by stormwater into storm drains and eventually into rivers and lakes.

These materials can persist in the environment for long periods and negatively impact wildlife and water quality.

Vehicle Fluids

Oil leaks, antifreeze, brake fluid, and other vehicle-related pollutants can be washed from driveways and parking areas into storm drains.

Even small amounts of these substances can affect water quality when multiplied across many vehicles and roadways.

Household Chemicals

Improper disposal of household chemicals such as cleaners, paints, solvents, and other hazardous materials can introduce toxic substances into stormwater systems.

These materials should always be disposed of according to local hazardous waste guidelines.

Winter Materials (Salt and Ice Melt)

Deicing products used during winter weather can wash into storm drains as snow melts. While important for safety, excessive use can contribute to elevated salt levels in waterways.

Careful application helps balance safety with environmental protection

Why This Matters

Each of these sources alone may seem small, but stormwater collects runoff from entire neighborhoods and communities. Over time, these small contributions add up and affect the health of local waterways.

Reducing pollution at the source is one of the most effective ways to improve water quality.

Related Topics

To learn more, explore:

• Pet Waste and Water Quality
• Leaves, Grass, and Yard Waste
• Household Hazardous Waste
• Fertilizer and Water Quality
• Ice Melt and Winter Water Quality
• Plastic Pollution and Litter

Stormwater systems are designed to move rain and snowmelt away from streets, buildings, and other developed areas to reduce flooding and improve safety. While the system is often out of sight, it plays an important role in every community.

Unlike wastewater systems, stormwater systems do not treat water. Their primary function is to collect and convey runoff to nearby waterways as efficiently as possible. Learn more: Stormwater vs Wastewater

From Streets to Storm Drains

In most neighborhoods, stormwater begins its journey at the curb or roadside. As water flows across streets and driveways, it enters storm drain inlets—those openings you see along curbs or in low areas of roads.

From there, the water enters a network of underground pipes or surface ditches designed to carry it away from developed areas.

Pipes, Ditches, and Channels

Depending on the community, stormwater may travel through:

• Underground storm sewer pipes

• Open roadside ditches

• Concrete channels or culverts

• Natural drainageways and creeks

All of these systems are connected and designed to move water downhill toward larger bodies of water.

What Is an MS4?

Many communities in Nebraska are part of a regulated system called a Municipal Separate Storm Sewer System, or MS4.

An MS4 is simply a stormwater system owned or operated by a city or other public entity that discharges into local waterways. These systems are required to follow state and federal regulations to help reduce pollution entering stormwater.

While the name sounds technical, the concept is simple: it is the network that carries stormwater from streets and neighborhoods to rivers and streams.

Construction and Development Areas

Areas under construction require special attention because exposed soil can easily wash away during rain events. To reduce this, temporary controls such as stabilized entrances, silt fences, and sediment controls are used to keep soil on site and out of stormwater systems.

These practices help prevent large amounts of sediment from entering local waterways during development.

Why Stormwater Is Not Treated

Stormwater systems are different from wastewater systems. Wastewater from homes and businesses is sent to treatment facilities, where it is cleaned before being released back into the environment.

Stormwater, however, is not treated. It is designed to move quickly through the system to prevent flooding, which means any pollutants in the water go directly into receiving streams and rivers.

A Connected Network

Although stormwater systems may seem local, they are part of a larger connected network. Water leaving a neighborhood eventually joins creeks, rivers, and watershed systems that extend far beyond city limits.

This is why actions taken in one area can influence water quality downstream.

Green infrastructure refers to practices that use natural processes to manage stormwater close to where it falls. Instead of quickly moving water away through pipes, these systems help slow it down, filter it, and allow more of it to soak into the ground.

These approaches can reduce flooding, improve water quality, and create healthier urban environments.

Tree Box Filters

Tree box filters are compact stormwater treatment systems installed beneath or around street trees.

They capture runoff from nearby pavement and use engineered soil and vegetation to filter pollutants while allowing water to infiltrate into the ground. Read more here.

Urban Wetlands and Ponds

Constructed wetlands and multi-purpose ponds are designed to temporarily store stormwater while allowing natural processes to improve water quality.

These systems can provide both flood control and environmental benefits, including habitat for wildlife and improved water quality.

Green vs. Gray Infrastructure

Traditional stormwater systems—often called gray infrastructure—rely on pipes, culverts, and channels to move water quickly away from developed areas.

Green infrastructure works alongside these systems by slowing down runoff, reducing peak flows, and improving water quality before water reaches those pipes.

Both systems are important, and in many communities they work together as part of a larger stormwater strategy.

Why This Matters

Green infrastructure helps communities manage stormwater more effectively while also improving environmental conditions. It reduces pressure on drainage systems, helps limit flooding, and improves the quality of water entering local rivers and streams.

Stormwater systems collect runoff from entire communities, which means small actions at home can have a big impact on local water quality.

Every property contributes to the larger watershed, so everyday choices help determine what ends up in local rivers and streams.

At Home

Simple changes around the home can reduce pollution entering stormwater systems:

• Keep trash, leaves, and debris out of streets and gutters

• Properly dispose of household chemicals and paints

• Recycle used motor oil and automotive fluids

• Avoid dumping anything into storm drains

• Use fertilizers and lawn chemicals carefully and only as needed

In the Yard

Yard care practices can significantly affect stormwater quality:

• Sweep grass clippings and leaves off driveways and sidewalks instead of washing them away

• Maintain healthy lawns to reduce fertilizer needs

• Use native or drought-tolerant plants where possible

• Redirect downspouts into vegetated areas when appropriate

• Avoid overwatering, which can increase runoff

Around the Street

Many stormwater impacts happen at the curb, where private property meets public infrastructure:

• Do not blow or rake leaves into the street

• Keep storm drain inlets clear of debris

• Report illegal dumping or blocked drains when observed

• Minimize vehicle leaks and clean up spills properly

Winter Practices

Cold weather introduces additional stormwater considerations:

• Use deicing products sparingly and follow label directions

• Sweep up excess salt or sand after storms when possible

• Store chemicals properly to prevent runoff during snowmelt

Why These Actions Matter

Stormwater systems do not treat water before it enters local waterways. This means prevention is the most effective tool available.

When many residents take small actions, the combined effect can significantly reduce pollution and improve water quality across the entire community.

Our Water, Our Responsibility

Protecting water quality is a shared effort. Every property, street, and neighborhood plays a role in determining the condition of local rivers and streams.

• Stormwater 101
• Homeowner’s Guide to Stormwater
• Green Infrastructure 101
• Flooding, Runoff, and Resilience
• Understanding MS4 Programs
• Stormwater Pollution Sources