Chapter 3. Streams

Description of the Resource

Streams are necessary components of a successful ecosystem and likely exist within HOA natural and developed areas. Streams not only provide beauty to a community, but they also maintain water flow, can improve water quality, and may support diverse vegetation communities and wildlife habitats.

Streams, stream banks, and the areas adjacent to them (collectively called the ‘riparian area’) provide many benefits to both the natural community and to us. The ability to understand streams both from a natural and a human perspective is important.

There are three classifications of streams: intermittent, perennial, and ephemeral streams; and they all serve different purposes but are equally important to your local ecosystem.

Perennial Streams

Water flows in these streams throughout the year. The primary water source can be from ground water, surface water, or a combination of both.

Intermittent Streams

Intermittent streams flow for part or most of the year but may carry no water during the dry season.

Ephemeral Streams

These streams flow only for a short time, usually after a large storm or snowmelt when there is an increase in water runoff. Ephemeral streams are very small and normally have a dry channel during the year.


A stream looks great in any park or backyard, but stream benefits extend beyond aesthetics. Water, even in the form of a small stream, can increase the property value of the community and homes. Streambeds and floodplains can store excess flood water in times of heavy rain, preventing damage to homes and streets. Streams also provide habitat for a diverse population of plants and animals.

Check out Appendices 3-1: Stream Management and 3-2: Natural Stream Process for more information about what could be in your stream.

Technical Best Management Practices

Debris/Trash Removal

Streams are a sensitive part of our ecosystem. Trash, hazardous chemicals, and runoff from lawn and garden chemicals negatively impact water quality in a stream. These impacts can be far-reaching, extending for miles downstream from the impact site.

National, state, and local laws prohibit dumping in streams. It is important for the HOA and individual homeowners to maintain these areas. Trash should never be dumped into a stream or any other natural area. This includes items such as grass clippings, leaves, pet waste, and landscape debris. These items contain large amounts of nitrogen and organic matter that may alter the ecosystem of the stream. In addition, grass clippings often contain toxic chemical residue from chemical lawn applications. These materials should not be dumped in streams or indiscriminately thrown into floodplains and riparian areas; instead, a well-placed and maintained compost pile at the edge of the homeowner’s yard can provide a source of compost and will keep these materials out of landfills.

Existing trash in streams, non-hazardous of course, can be easily removed by HOAs or homeowners. Removing trash and debris will not only clean up your stream and make your backyard or community look nicer but will also benefit water quality far beyond your neighborhood.

See Appendix 3-3: Stream Debris for more information.

Stream and Riparian Area Improvement

Riparian areas include the natural vegetation along streams and rivers and often encompass flood plains, wetlands, and upland areas along watercourses to form a natural corridor. Riparian corridors provide a buffer between developed areas and the stream. These naturally vegetated buffers filter pollutants and sediment out of surface water runoff before reaching the waterway. Intact riparian corridors form a connection between larger natural areas which allow for movement of plants and animals. The trees and plants in the stream buffer also stabilize the soil and prevent erosion. There are many things a HOA can do to enhance streams and the areas along them:

Maintain or Create a Buffer: To protect streams and maximize their benefits, the appropriate width of the vegetative buffer between the stream and developed property depends on many factors and can vary greatly. Small streams may require a riparian width of 25 to 50 feet on either side of the stream channel. Larger streams may require a buffer of hundreds of feet or more depending on slopes, soil types, and the width of wetlands associated with streams. In general, the riparian area should include the floodplain, any wetlands associated with the stream, and the valley slopes.

Limit the Use of Landscape Chemicals: Riparian areas and wetland buffers do have the ability to filter pollutants before they enter the stream. The wider the buffer, the more pollutants are removed. In a residential area where the use of lawn fertilizer, weed control chemicals, and pesticides is common, streams are often harmed due to the lack of a buffer. HOAs and residents should understand that pesticides, herbicides and fertilizers represent the greatest threat to water quality in residential areas. These chemicals can negatively affect drinking water, pollute recreational ponds and lakes, and cause the death of wildlife including fish and birds. The use of these chemicals should be carefully considered, understanding that many times these chemicals are frequently unnecessary and can be overused in the home landscape.

Limit Mowing Near the Streambank and Buffer: Riparian areas can be easily degraded. Filling, trash dumping, and invasive plant species are also common causes of riparian buffer degradation. But, perhaps the most common cause of riparian area degradation is mowing. This destroys the natural vegetation of the riparian corridor and reduces the functionality of the buffer zone.

The easiest and often most effective means of riparian area enhancement is to maintain the natural vegetation of the stream corridor. Mowing, brush hogging, tree cutting, and herbicide use should be avoided to allow the growth of the plants that are native to your area.

Plant Native Plants: If there is only grass or bare soil near streams in your community, it is recommended to plant trees, shrubs, and perennialsand/or broadcast a natural seed mix. Using native plants is usually the best choice. Nurseries specializing in native plants can be found in your city or on the internet and can help you select the appropriate plant material for the site. If a limited budget is an issue, transplanting from other natural, undisturbed areas, or even “rescued” from a natural area being developed in your neighborhood, may be options. In many instances, planting may not be necessary because nature has an amazing capacity for regeneration. Left alone for a growing season or two, disturbed areas may quickly become re-vegetated on their own. Management may be limited to controlling invasive plant species. In all cases, an undisturbed buffer with invasive plant species is still preferable to a mowed and disturbed area. Many municipalities now have laws requiring a certain width of natural riparian area and/or building setbacks from streams. You should check with your municipal and county officials to see if riparian laws, policies, or guidelines exist in your area.

See Appendices 3-4: Community Riparian and Wetland Guidance and 3-5: Forested Strips for more information.

Streambank Erosion Control

Streambank erosion can be more than a nuisance and simply unattractive. Erosion can be serious and result in the loss of land use, the loss of land, and damage to buildings. Streambank erosion occurs when the stream cuts away at the side of the channel at an accelerated rate. Heavy rain, wind, ice buildup, or vegetation removal can increase erosion of the bank. Usually, excessive streambank erosion can be attributed to an increase in water flow, especially stormwater. This increase is frequently a result of upstream development. When land is developed, vegetation is removed and replaced with hard surfaces so more water runs off parking areas and buildings into the nearby streams.

There are methods that can be used to prevent and/or control streambank erosion. As discussed previously, it is important to maintain and/or plant natural vegetation around the stream. The roots of plants help to hold and stabilize the streambank soil. Trees and shrubs, in particular, help stabilize a streambank and should not be removed.

Correcting severe streambank erosion will likely involve significant earthwork and the use of a contractor. An effective stream restoration project will restore existing areas of streambank erosion, prevent further erosion, and restore the stream channel to a natural state. These major restoration projects may be necessary to protect propteries and even human life, and are typically time consuming and expensive.

It is important to note that any fill material, including concrete, rock, riprap, pilings, or other material placed into the stream or along the bank may require a permit. Your district office of the U.S. Army Corps of Engineers as well as your state environmental protection agency should be contacted for guidance. Your county Natural Resources Conservation Service (NRCS) or Soil and Water Conservation District office will also be able to provide advice regarding streambank erosion remedies.

Water Quality Testing

Generally, water quality testing is not necessary. Larger streams and rivers are likely tested periodically by state and/or local agencies. These data may be available through your state environmental protection agency, or can be accessed on the U.S. EPA’s website at Smaller, unnamed streams are unlikely to have existing water quality data, and you can contact your county cooperative extension service office, sewer and stormwater agency, or local health department for assistance with water quality questions for these streams.

If you are interested in knowing the current water quality of the streams in your community, you can use several methods to assess the situation. One way is through chemical testing of the water to measure certain water properties. These tests include:

  • Dissolved oxygen provides a measure of how much plant and animal life the stream can support.
  • Turbidity is a measure of water clarity.
  • pH which tells how acidic or basic the water is. Few organisms can survive in water with a pH below four and above nine.
  • Temperature can affect the mortality of animal life.
  • Fecal coliform which is usually residues from pet waste, agricultural fields, and high goose populations.
  • Nutrients caused by sediment and chemicals washed in by stormwater runoff.

Another way to test water quality of a stream is to see what organisms are living in it. Tests that count numbers and different types of invertebrates in the stream provide an indication of stream habitat quality as well as water quality.

Water quality testing requires specialized equipment and trained professionals. If a need arises to have the water tested, your state environmental protection agency as well as local laboratories should be contacted for guidance on how to sample and what parameters to test for based on your particular needs. HOA’s can also inquire with local high school science classes and stream stewards to perform this work.

Beaver Dam Control

Beavers can change the landscape more than any other mammal, second only to humans. Beavers build dams for shelter and protection from predators. Damming a stream raises the water level around the dam and creates a moat for protection. Without knowing it, beavers are creating one of the most biologically diverse ecosystems–wetlands.

Beaver dams can be seen as a nuisance or benefit. The section below explains the benefits and disadvantages of having a beaver dam in your stream and provides strategies to control beavers if they become a problem.

Benefits of beaver dams:

  • Erosion control. Beaver dams can raise the water level of streams, slowing or stopping bank erosion from meandering streams.
  • Development of new wetlands
  • Formation of natural lakes and ponds
  • Flood mitigation (floodplain holding capacity increased)

Disadvantages of beavers and their dams:

  • Flooding of roads yards or parks
  • Chewing of expensive ornamental trees and shrubs
  • Damage or removal of trees in natural forested areas

Before trying to control the beavers, make sure that they are causing real damage or doing something that actually warrants control or removal. If the animals are being destructive toward your trees, wrapping trees in chicken wire or something similar can slow or stop beavers from chewing.

The dams can be removed, but often the beavers will re-build. Nuisance beavers can also be trapped and relocated. This should not be done by anyone other than a wildlife or animal control specialist.

Owner/Management Best Management Practices

As a HOA leader or representative, there is a business side to managing residential streams. You do not have to be an expert in every aspect of stream management, but you should be aware of local stream laws and regulations: how to hire a contractor, how to monitor work projects, manage HOA funds, interact with volunteers and employees, and how to educate and inform residents. With this knowledge, you will be able to maintain and restore your streams and thus maximize the benefits of these valuable natural resources.

How to Hire a Consultant/Contractor

It will likely be the job of the HOA to hire a contractor to address significant issues with your stream. It may be necessary to hire a stream/construction professional when there is a need to manage stream degradation problems. If restoration of your streams becomes necessary, coordination with the U.S. Army Corps of Engineers or appropriate regulatory authority may be required prior to any work in streams. In most cases, a site visit is made and an in-field inspection of the stream is performed to evaluate the issues involved.

State and local laws may also regulate these and other activities such as tree clearing, mowing, and disturbances within the upland buffers surrounding the streams. Local, state, and federal officials should be contacted regarding stream regulations. A stream professional can identify stream problem areas and coordinate with government entities to ensure stream regulations are followed.

When considering a stream professional, don’t be afraid to ask questions, such as:

  • What are your qualifications and what does your work entail?
  • Can you provide us references from similar projects your company has done?
  • What are our options for dealing with this issue(s)?
  • Will you coordinate obtaining all the required permits and approvals?

Obtaining Estimates

Ask for an estimate, and get more than one estimate; often there is no charge for this service. You can also consider creating a request for a bid that details the work you want to accomplish and then provide this to several companies. This way, all contractors bid on the same work, making it easier for you to compare their responses. However, you should not always select the lowest bid. When examining bids to determine which company will provide you the best service, take into account all information provided, such as certifications, credentials, insurance coverage, work description, and cost. Most importantly, get the bid in writing.

Contract Specifications

Most companies provide a contract for services, or you can create your own. The contract should cover some general terms with specific details based on the specific project. Basic sections in most contracts include definitions, scope of work, liability and insurance requirements, and payment terms.

Monitoring/Inspecting the Work

If a stream restoration project occurs within an area managed by the HOA or near your property, it is acceptable to ask questions and find out what is happening.

Like any purchase of goods and services, you want to be sure you get what you asked and paid for. During the course of the project and after the work is complete, you have the right to inspect the work and ask questions at any time. Do not pay any invoice until you are satisfied that the specified work has been completed properly.

Understanding Federal, State, and Local Laws and Ordinances

Certain permits are required for stream restoration and bank erosion control. You may remove trash from a stream, but for major streambank and erosion control work, a permit is needed and contacting a professional is required. See Appendix 3-6: Permit Checklist for more information.

Using Volunteers

Volunteers are a great way to get work done. If many people are interested in a stream clean-up, ask your HOA to organize one. Picking up trash does not require any permits and it will help to improve water quality and make your stream look great. Organizations like Trout Unlimited or your local watershed group can be a good source of volunteers.

Homeowner Education

Learn as much as you can. The more you know, the more you will be able to share with others. As a leader in your association, tell others about the importance of keeping your stream clean and what a clean stream can bring to your community.

Sources for Assistance

Contact your environmental protection agency, your soil and water conservation office, or your department of natural resources with any questions or concerns you may have. For additional stream information, research these sites:, and


To have clean, beautiful, healthy streams it is necessary to control pollutants and garbage from draining into the water and to maintain sufficient buffers of natural vegetation. Proper care and management of your stream can make a big difference in water quality and aesthetic appeal, and it can prevent damage to community property from streambank erosion.


3-1: Stream Management
3-2: Natural Stream Processes
3-3: Stream Debris and Obstruction Removal
3-4: Community Riparian and Wetland Guidance
3-5: Forested Buffers
3-6: Permit Checklist for Stream Modification

Helpful Websites