Protect Natural Floodplain Functions

KEEP YOUR CREEK HEALTHY AT HOME

Everyone lives in a watershed, and almost everything that is dumped on the ground will eventually end up in a stream!

 

 

 

Maintain a Healthy Septic System
Have your system pumped every 3 to 5 years.
Domestic wastewater from a failed septic tank can cause water quality problems for surface and groundwater due to high levels of nitrate and phosphate.

Don’t poison your system by pouring harmful chemicals such as solvents, oils, paints, thinners, disinfectants, pesticides, and poisons down the drain.
They can kill bacteria that help purify sewage and they can also contaminate groundwater. Dispose of these items safely.

Dispose of all wastewater in a approved system.
Don’t use a separate pipe to carry wash water to a small creek or the woods. This greywater may contain soaps (or other chemicals) and germs.

Control Runoff from Your Yard
Avoid mowing right up to creek bed.
Let the native trees and shrubs grow along banks for stabilization and to provide shade and habitat for native wildlife

Don’t let exposed dirt in your yard run off into a stream.
Prevent erosion and replant exposed areas right away. Mud is pollution too – it can suffocate fish and other water critters when it runs into the stream.

Use porous materials for your driveway, yard and landscaping.
to allow water to seep into the ground.

Practice sensible pest control.
Overuse of pesticides increases the chemicals washed downstream and does not benefit the plants. Also pesticides can eliminate all bugs. Discourage harmful garden bugs by encouraging helpful bugs and animals.

Be careful with fertilizers,
Which can hurt wildlife by overwhelming streams with high nutrient levels.

Make sure rain gutters and other pipes do not carry water directly into a creek.
Runoff from roof surfaces carries contaminants that contribute to the decline of creek health. Pipes projecting directly into a creek bank cause erosion. Consider collecting rainwater in a cistern or rain barrel for use on ornamental gardens and lawn.

Dispose of Wastes Properly
Don’t dump anything down storm drains.
Storm drains often flow directly into local streams. Dispose of used automotive oil at the local recycling center.

Avoid hosing down paved surfaces or washing your vehicle in the driveway or street.
Even “biodegradable” soaps are toxic to fish and wildlife. Wash vehicles on grass or other unpaved areas. Or, use car washes where the water is recycled.

Drain your pool or hot tub into landscaping after letting chlorine dissipate for a week or two.
Don’t use copper-based algicides. Chlorine and copper algicides used in swimming pools and spas are toxic to aquatic life and other wildlife.

Clean up after pets on sidewalks, patios, or gutters so that their waste will not was into surface waters.
Dog and cat feces add excessive nutrients and bacterial pollution to water, which decrease water quality. Horse and livestock manure also harms water quality.

 

FARMING PRACTICES THAT HELP KEEP CREEKS HEALTHY

High nutrient levels in waterways will stimulate unwanted algae growth and degrade stream health.

 

Carefully Manage Application of Fertilizers
Do not over-apply nutrients in a quest for unrealistic yield goals. Instead have your soil tested and follow soil test recommendations on nutrients, if needed.
Let the native trees and shrubs grow along banks for stabilization and to provide shade and habitat for native wildlife.

Apply nitrogen and phosphorus correctly.
Promptly incorporate fertilizer into soil by disking, plowing, or rotary tilling to decrease loss due to erosion or runoff. Be careful to apply fertilizer only to crop areas. Don not apply fertilizer when it is windy which can cause blowing outside of crop areas. Do not spread just before it rains.

Time nitrogen application appropriately.
Nitrogen should be applied in small amounts as needed.

Control Erosion
Maintain a soil cover.
Leave crop residues on the soil surface during the winter. Do not till too early in the spring. Consider use of a cover crop to trap and recycle nutrients for use by later crops.

Manage the soil for maximum water infiltration and storage.
Increase soil’s water-holding capacity by adding organic matter and by aerating soil to increase water absorption.

Maintain vegetation on ditch banks and in drainage channels.
If possible construct ditches larger than needed so the bottoms can be left vegetated to trap sediment and other possible pollutants.

Slope field roads towards the field and seed roads with a perennial grass cover.
Water erosion and dust from traffic on field roads contribute to soil loss and potential pollution of streams on farms.

Plow and plant crops along contour lines.
Plant crops in rows perpendicular to the slope of the field to save topsoil from erosion.

Shape and seed field edges to filter runoff as much as possible.
Do not plow up to the edge of the field. Leave a buffer strip along drainage ways and establish a perennial sod.

Limit Use of Pesticides or Herbicides
Do not rely only on chemicals to control your pest and weed problems.
Pesticides and herbicides may poison aquatic life if they are washed into streams. IF you do use these chemicals, try the least toxic products first.

Use cultural practices to prevent pest problems whenever possible.
Rotate crops, plant pest-resistant varieties, encourage biodiversity and beneficial insects, practice good sanitation, use compost and mulch, alternate rows with herbs, and provide water and houses for pest-eating birds and bats.

Protect Waterways from Livestock Waste
Fence animals away from streams, drains and sensitive wetland areas.
IF cattle and livestock are allowed access to waterways their waste will be placed directly in the water, and animal traffic will cause soil disturbance and increased sediment.

Feed, water, and pasture areas where livestock congregate should be located so that runoff is filtered through vegetative buffer strips.
Even though vegetated buffers are highly effective at removal of excessive amounts of nitrogen, when manure accumulations at any site, it should be correctly applied to the land.

 

Stream Processes – A Guide to Living in Harmony with Streams

The following information includes excerpts from the Chemung County Soil & Water Conservation District, Stream Processes – A Guide to Living in Harmony with Streams (August 2006).  To view the entire booklet, please “CLICK HERE

Many well-meaning attempts to address stream problems have resulted in the creation of even more problems. In an attempt to avoid those mistakes, this page includes information about how streams work and guidelines for living in harmony with them. It is NOT meant to be a training site for managing streams, rather information to understand stream processes – and why streams don’t always behave how we would like them to.

NATURAL STREAM PROCESSES

Streams are complex systems that do complicated work. In their natural state, healthy streams perform many functions – such as purifying water, moderating floods and droughts, and maintaining habitat for fisheries, birds and wildlife. Stream and river systems gather, store, and move snowmelt and rainwater in synchrony with nature’s cycles. In the process they move sediment and alter landscapes.

Stream Character
Streams come in many shapes and sizes. They range in character from steep, swift-flowing mountain streams to flat, slow-flowing pasture streams. The nature of a stream is influenced by the amount of water the stream carries, the geology and soils it flows through, and the shape and slope of the valley that confines it. Each stream channel is formed, maintained and altered by the stream itself through the process of erosion and deposition of sediment. Over time the stream will establish a cahnnel shape that accommodates its spring thaws and summer droughts. If something happens to change the conditions that have shaped the stream, then the stream will change its channel to adapt to different conditions.

 

SLOPE
The Slope of a stream-bed contributes to how water moves and how much sediment it can carry. The steeper the slope, the faster the water moves and the more bed-load (i.e. sediments, silt, sand, gravel, boulders, and organic materials) can be carried through the channel. In flatter areas, where the stream has less slope, it will tend to deposit gravel or sediment. The stream determines its own slope by erosion, deposition, and adjusting its channel length by meandering.

 

CHANNEL
The banks within which low and moderate flows occur defina a stream’s channel. The deepest areas are generally connected, forming a low flow channel. The stream-bed is the foundation of a stream that supports the banks. Stream-beds are composed of a variety of materials, which can range in size from large boulders and rocks, to gravel, sand, silt, and clay particles. The scouring and deposition of this sediment shapes the stream channel and its floodplain. Some channels are relatively stable, with little change in the channel shape over time. Other channels are actively adjusting and changing their shape, usually in response to changed conditions, such as increased flow or a modification along the stream. This change can occur quite rapidly 0 which may cause problems for nearby development – or can occur slowly over time.

FLOODPLAIN
Well-established rivers and streams usually have flat valley floors, called floodplains that are periodically inundated by high water. The floodplain is an important part of the stream system, because it provides a place for water to go when it cannot be contained in the channel. When water fans out across the floodplain, the flow velocities are dramatically decreased and the energy of the stream is dissipated. this relieves the pressure on streambanks and allows the water to be stored, thereby reducing the amount of flooding that occurs downstream.

The floodplain is formed by the stream itself through the natural processes of erosion and deposition. Over time, the stream channel can and will move across the floodplain, eroding and re-depositing material. People who live on floodplains can attest to the volumes of mud that a single flood can leave on their yards or in their houses. Some have also witnessed the erosion that occurs when the stream channel adjusts its location on the floodplain. This erosion and deposition of bank material is another mechanism by which energy is dissipated in the floodplain.

 

POOLS & RIFFLES

Protect Our Streams Some streams have alternating deep and shallow areas called pools and riffles. The deep, slow water in pools provides shelter and resting areas for fish. Shallow, swift water in the riffles provides fish with spawning and feeding areas. In addition to their value to fish and aquatic life, pools and riffles help to maintain channel stability. Water leaving a deep pool needs to flow upward into the shallow beyond. This upward flow of water slows it down and dissipates energy.

 

MEANDERS
Many streams naturally meander. These curves slow down the water and absorb energy, which helps to reduce the potential for erosion. The velocity of a stream is greater on the outside of a bend. The increased force of this water frequently results in erosion along this bank, extending a short distance downstream. On the inside of the bend, the stream velocity decreases, which results in the deposition of sediment, usually sand and gravel, along this bank. If you could look at the long-term history of a valley over hundreds or thousands of years, you would see that the stream has moved back and forth across the valley bottom. In fact, this lateral migration of the channel, accompanied by down cutting, is what has formed the valley.

BRAIDED CHANNEL
Protect Our Streams Although most streams have a single channel, this is not always the case. Multiple-thread or braided streams can occur when the stream receives more sediment than it can transport. The excess load is deposited within the channel area, with the channel and island locations shifting from year to year. Factors that contribute to channel braiding include high sediment supply, extensive streambank erosion, backwater effects (which reduce a stream’s velocity), and flashy runoff conditions that result in rapidly changing flows.

Erosion often occurs at the bends in a stream channel. This does not suggest that straightening a channel will eliminate erosion problems – quite the contrary. Straightening a stream will result in a shorter, steeper channel, in which water moves faster and has more energy. This change may upset the balance of the stream, causing erosion, loss of land, increased sediment supply, loss of aquatic habitat, or other problems.

 

Emriver River Model Clips
(Source: Gough, S. 2007. River geomorphology videos. DVD. Little River Research & Design, Carbondale, IL; www.emriver.com.)

The following videos were created to help better understand geomorphic processes in rivers with special attention to the effects of channelization and gravel mining.

Channelization, large meanders

Protect Our Streams (Flash Video 8.6MB Dec21 09)
(2:35 m)

This is a time-lapsed Emriver channelization demonstration in which a meander loop is cut off. In this case the channel length between two points is more than halved, so slope would increast by a factor of 2+. The playback speed varies and is noted on the video.

Note the relative stability of the system before channelization, in which a small amount of sediment is moving throught the reach, but there is little bank erosion and by one definition – sediment in = sediment out – the system is very stable. A moving circle and the words “uniform bedload transport” illustrate this.
After the channelization, note bank failures both up and downstream, and that the channel slowly reestablishes a meandering form so that its overall length is about the same as before the channelization. Graphics show how bedload transport greatly increases due to incision and bank erosion upstream of and within the reach.

During the remeandering process, note that there is a net export of sediment – you can see this by visually comparing sediment movement into the reach versus that out of it.

Near the end of the clip (2:17), transect graphics appear. These show the wide, unstable nature of the channelized reach versus the narrow, more stable upstream reach.

Headcut in Straight Channel

(Flash Video 2MB Dec21 09)
(0:35 m)

Sediment is removed from the lower end of a straight reach causing one or more headcuts to travel upstream. The first headcut is emphasized with an arrow that fades as the headcut becomes indistinct. As the incision progresses the channel begins to meander and form bars/terraces and the channel evolves. Use the pause control in this short clip to take your time looking at these forms.

Good short illustration of headcutting, incision, and subsequent channel evolution.

Tributary Incision Caused by Main Channel Incision

(Flash Video 3.2MB Dec 21 09)
(0:58 m)

This clip shows how head-cutting and incision in a main channel influences a smaller tributary. Sediment is removed from the larger channel (here using an aspirator, out of the frame to the right) causing it to incise. The head-cutting and incision affect both the main channel and the smaller tributary. Dye pulses show velocity and relative depth. Note how incision is indicated by the formation of terraces in both channels.

This has many applications to real world problems. This demonstration shows how tributaries are influenced by vertical instability such as that caused by channelization. We can compare this with the large gullies and tributary incision seen in the aerial photos of the channelized Grand River (see the first video on this page).

Meander Development in a Straight Channel

Protect Our Streams (Flash Video 2.3MB Dec21 09)
(0:43 m)

A straight channel is formed in the Emriver model. Speed is x10. After flow begins, the channel slowly forms regular meanders and point bars. Note how the meanders tend to migrate in a downstream direction. The meander bends also expand the meander belt width until about 0:34, when they cease to move outward and migrate only in a downstream direction. Geomorphologists would argue that the channel reaches a point of stability then as sediment inputs to the reach match outputs and the reach no longer has net erosion. You can see this by observing sediment movement into versus out of the reach.

Wetland Draining Caused by Incision, Oblique Upstream View

(Flash Video 1.6MB Dec21 09)
(0:28 m)

Here the view is upstream. A Clearly defined headcut moves up through the channel, the water table is lowered as the channel incises, and the floodplain wetland becomes dry. Note formation of small terraces on both sides of the channel as it incises.

Floodplain Wetland Draining Caused Channel Incision

(Flash Video 2.4MB Dec 21 09)
(0:43 m)

This clip shows a vertical view of a small wetland being drained as the channel near it incises and the water table elevation drops. Note the formation of a sequence of terraces as the channel incises. Here incision was caused by removal of sediment downstream using an aspirator.