As winter approaches and rain turns to snow, it is still important to consider stormwater pollution. Pollutants such as soaps, fertilizers, automotive fluids, and pet waste can collect in the snow pack, accumulating until a thaw suddenly dumps them into the storm water system. Contaminants that end up in the storm drains are carried off, untreated, to streams and larger bodies of water that are used for drinking, swimming, or fishing. Here are a few helpful habits to reduce the amount of harmful pollutants entering storm drains this winter season:

• Winterizing vehicles: Check that your car is not leaking oil or other fluids. It takes only a small amount of motor oil to pollute thousands of gallons of water. Also, dispose of drained fluids properly. Many service stations will collect used motor oil and recycle it.

• Washing vehicles: On a warm winter day, you may be tempted to break out the hose and bucket to get some of the road grime off of your car. Take a moment to see where that runoff is going. Does it wash down the driveway and into the storm drain? If so, all that salt and dirt will enter a stream or pond. Using a car wash facility may cost a few dollars more, but the water will be treated before being released into the watershed.

• De-icing driveways and sidewalks: While it may be habit to stock up on salt for the winter, many people would not consider dumping a bucket of salt on their lawn in the summer. But the results are similar. Salt runs off of your sidewalk and onto the surrounding soil. Consider more environmentally-friendly deicing products.

Help Keep Winter Salt and Sand Out of Walnut Creek!

At your home, you can prevent pollution to the river and backwaters by limiting the amount of salt and deicers you use on your driveways and sidewalks. One teaspoon of salt can contaminate five gallons of water!

  • As a rule of thumb, if there is a layer of salt remaining on your driveway after the ice melts, you used too much salt. If you do have excess sand or salt, sweep it up and throw it away so that it is not washed into the storm sewer.
  • The earlier you shovel after a snowfall, the less likely you are to need salt.
  • Consider using an anti-icing agent before it snows. It will prevent the snow from bonding with the pavement and speed the melting process.


When mowing your yard, make certain that you do not blow grass clippings into the street. When mowing, make the first few passes with the lawnmower blowing the grass clippings into the lawn NOT the street. If there are grass clippings on the street or sidewalk, use a broom or leaf blower to blow them back into the lawn. Do not use a hose to wash them into the street or storm drains. Grass clippings that are blown into the street eventually enter the street storm drain. The grass clippings can form blockages in the storm drains or flow down Walnut Creek. Grass clippings contribute nutrients such as nitrogen and phosphorous, which cause unwanted and uncontrolled growth of algae and aquatic weeds in the waterways.
Also, please remember that City Code requires the growth of grass or weeds can be not be over 6 inches in height!


With autumn here, leaves are falling from the trees. Residents are asked to help keep the stormwater intakes free and clear of leaves and grass clippings by please
avoiding raking leaves into the street. This is because leaves in the street eventually end up in the storm sewer, clogging pipes and causing flooded streets. Windsor Heights stormwater flows to underground culverts and creeks, and eventually find its way to the Raccoon River, which is the source for all drinking water. Clean stormwater runoff not only helps keep drinking water clean and safe, it also helps protect aquatic life.


Storm water can pose a risk to our water resources.
Pollutants in stormwater can impact lakes, streams and
rivers. New programs to control storm water pollution are
being adopted by our community.

Storm water runoff is rainfall or snowmelt that runs off
impervious surfaces like roads, buildings, and compacted
soils. Storm water runoff is collected and conveyed
through storm sewers directly into streams, rivers, and
lakes without being treated.

Pollutants accumulate on impervious surfaces between
rainfall events. Frequent, small rains wash pollutants into
streams, rivers, and lakes. These pollutants negatively
impact water quality.
As communities grow, impervious areas increase.
Greater impervious surfaces cause the volume and rate of
stormwater runoff to increase. This can result in flooding,
stream channel degradation, and increased water pollution
in our surface waters.

The traditional approach to storm water management
focuses primarily on flood control. Today, our city is
required to manage for both water quality and quantity by
using practices that infiltrate more rainfall and reduce the
volume of storm water runoff.

To comply with new federal regulations, our city is
required to implement a new storm water management
program. Some requirements include:
1. Managing storm water runoff for water quality protection,
2. Reducing sediment loss from construction sites,
3. Developing ordinances to meet program goals,
4. Inspecting storm drain outlets for unwanted discharges,
5. Providing public education and involvement.

Daily activities can impact water quality. Most rainfall
drains untreated to streams and lakes through storm
drains in neighborhoods. There are many ways you can
prevent storm water pollution:
1. Wash your car at a carwash or on the lawn, not the
2. Re-direct roof drains to gardens or other vegetated
3. Properly dispose of all hazardous household waste
4. Minimize use of fertilizers, and
5. Clean up after your pets.



Trees play an incredible role in reducing stormwater in several ways and removing or filtering pollutants that would otherwise wind up in our waterways.

Interception    Tree canopies intercept and capture rainfall, reducing the amount that reaches the ground. In urban and suburban settings, a single deciduous tree can intercept between 500 and 760 gallons per year, while a mature evergreen can intercept over 4,000 per year.

Soil Infiltration     Tree roots allow for better infiltration of rainfall with rates of up to 15 inches per hour. The leaf acts as a sponge, allowing for slow infiltration into soils before releasing it to natural channels and recharging ground water.

Evapotranspiration     Trees consume stormwater through a process called evapotranspiration. Water is taken up by roots and move up through the tree until it is transpired back into the atmosphere as water vapor. A single mature oak tree can consume (transpire) over 40,000 gallons of water each year.

Phytoremediation     Trees are very good at removing pollutants such as nitrates & phosphates; and other contaminates such as heavy metals, pesticides, solvents, oils, and hydrocarbons that are found in stormwater.

Riparian Buffers      Trees protect and buffer streams and are critical to maintaining healthy, clean streams. Tree roots provide streambank stability, reducing erosion, filter out sediments, remove nutrients, shade and cool the water, provide habitat for many different species, and provide the primary food source for aquatic insects that are a critical part of the aquatic food chain.