Natural Resources Guidelines for Recreation Path & Trail Planning

VALUES & CONSIDERATIONS FOR

Water Quality and Aquatic Habitat

Two distinct, but closely related, river (and to some extent, lake) issues need to be considered in bicycle or any transportation path planning: water quality and aquatic habitat protection. Most of the threats or impacts to water quality come from the adjacent land and so it is land activities and land management techniques that are the considerations. The threats or impacts to aquatic habitat can come from either land uses or from instream alterations. The issues and considerations for both of these aspects of river and lake protection are described below.

Water Quality

The greatest impairment to water quality in Vermont comes from nonpoint sources (diffuse sources) of poilution with sediment being the largest single cause of water quality problems in rivers. The sediments and attached nutrients that end up m our state's rivers and lakes come from numerous human activities along the shore and in the watershed including construction, road maintenance and repair, agricultural activities and logging. Buffer strips, which are bands of native vegetation, are effective and inexpensive (especially when left in place versus being re-established) ways of reducing sediment and nutrient pollution. A good buffer strip with trees, shrubs and ground-cover plants as well as an uncompacted soil surface will slow runoff allowing sediments to settle out and reducing the erosive force of the water. Sediments will become incorporated into the soil structure and nutrients will be taken up by the plants or also become part of the soils.

CONSIDERATIONS: Bikes and pedestrian paths should be constructed so that the water quality of lakes and rivers are protected, maintained, and improved to the greatest extent possible. The level of existing disturbance to the lakeshore or river corridor, soils and slopes, and construction erosion are important considerations: ~ Stretches of undeveloped river corridor or lake shoreline should be avoided whenever possible in order to prevent fragmenting natural communities, providing corridors for the introduction of alien species (plant and animal), disturbing or destabilizing soils and banks and encouraging further development and disturbance. ~ Depending on the soils, slope of the land, size of the river or stream and vegetation community present, there should be a buffer strip of adequate width between any path and the river bank or lakeshore. In general, a buffer strip should be at least 50 to 100 feet (15 to 30 meters) for water quality protection. In areas with more erodible soils or steep slopes, the buffer strips should be wider.

Aquatic Habitat

Vegetated lake shorelines and streambanks provide habitat for fish and other aquatic life. Lands adjacent to lakes, rivers, and wetlands should be protected, maintained, and improved so that they may serve the following aquatic habitat functions:

REFUGE HABITAT--fish like all other animals must have places that provide protective cover. Tree and shrub growth at the edge of the water provide overhanging branches, stable undercut banks, and instream snags.

STABLE STREAM FLOWS--a wider band of soil and vegetation will act as a sponge moderating peak flows during high runoff periods. More severe flow fluctuations will occur without these natural "sponges" and create a stressful environment for fish and other aquatic life.

COLDER WATER--cold water fish, especially adult trout and salmon, thrive in shaded streams or in the depths of larger rivers. Other "cool" water species, including younger fish, need the shaded areas along lake and river shorelines. When the shoreline or streamside canopy is removed, water temperatures can increase 10-20 degrees and fish may succumb to the stress of low dissolved oxygen concentrations.

FOOD SUPPLY--vegetation is the base of all food chains. In small shaded streams where little sunlight reaches the water, aquatic ecosystems rely on insects adapted for capturing the food contained in leaves and twigs falling from streamside vegetation. Fish key in on the life cycle of these insects for their own feeding success. Insects falling into the water from shoreline vegetation are important food sources for both lake and river fisheries.

CLEAR WATER--turbid water filled with sand and silt, brought on by unstable, eroding shorelines and streambanks, can have several illeffects on fish. Sedimentation covers fish spawning gravel and eliminates insect habitat in lake and stream bottoms. Turbid water clogs fish gills and makes it difficult for fish to see their insect food.

MEANDERING STREAM CHANNELS-meandering flow creates a sequence of pools and riffles within the stream. If the channel is straightened and/or widened, stream habitat becomes more uniform. The loss of cutting power on the outside bends of a stream results in the loss of deep pools that are important refuge habitat for adult fish. Erosion of inside meanders is accelerated both upstream and downstream of the straightened reach, encouraging more channelization, and covering riffle habitat with sediments.

CONS1DERATIONS: Bikes and pedestrian paths should be constructed so that the physical nature of lakes and rivers are protected, maintained, an improved to the greatest extent possible. The level of existing disturbance to the lakeshore or river corridor is an important consideration:

Summary

Two distinct, but closely related, surface water issues need to be considered in path and trail planning: water quality and aquatic habitat protection. Good water quality and aquatic habitat assure a diversity of plant and animal life and make the resource more enjoyable for recreation purposes. The greatest impairment to water quality comes from nonpoint sources of pollution with sediment from erosion being one of the most significant causes. Aquatic habitat is lost when the stream course is changed, the streambanks are altered, or the shade of overhanging vegetation is removed. The primary considerations in planning and developing paths and trails that are along or cross waterways include:

Well planned access points to a stream will give the path and trail user the unexpected pleasure of seeing the watercourse while allowing the stream to flow freely.

Path Planning Recommendations -- Water Quality and Aquatic Habitat

Answer the following questions and use the recommendation to plan a trail or bicycle path that will protect and enhance water quality and aquatic habitat. Notes are provided at the end to further explain the recommendations and indicate the organizations and agencies that may provide assistance.

Notes

BUFFER WIDTHS

A table uses the formula to provide a quick reference for determining buffer widths. In general. where there are slight to moderate slopes and soils that are only slightly to modeiately erodible. buffer widths are needed to protect and maintain water quality and aquatic habitat. When slopes are moderate to high and soils are moderately to highly erodible, then buffer widths of 100 to 400 feet are needed. These tables and the associated formula are presumably available from the Water Quality Division at the address noted at the end of this fact sheet.

Resources

A Classification of Natural Rivers. 1994. David L. Rosgen. Catena. Vol.ZZ. No. 3-lune 1994. pgs 169-199.

Best Management Practices for Erosion Control During Trail Maintenance and Construction. 1994. lohn Twitchell et al. State of New Hampshire Trails Bureau. Concord, NH.

Erosion Control: Vermont Handbook for Soil Erosion and Sediment Control on Conrtrudion Sites. Special Publication No. 3 1982. Vermont Geological Survey and Vermont Department of Environmental Conservation. Waterbury. VT.

Erosion. Land Use, and Stream Ecology: A Manual for Lake Champlain Basin Communities. 1992. Linda Henzel. Lake Champlain Committee, Buliington, VT.

How Creenways Work: A Handbook on Ecology. Second Edition. 1992. lonathan M. Labaree. National Park Service and Atlantic Center for the Environment. Ipswich. MA.

Landscape Restoration Handbook. 1993. Donald Harker. Sherri Evans. Marc Evens, Kay Harker. Lewis Publishers. Boca Raton. FL.

Native Vegetation for Lakeshores. Streamsides. and Wetland Buffers: What you need to know to reestablish or enhance buffer strips along water and wetlands in Vermont. 1994. Catharine Kashanski Vermont Department of Environmental Conserva tion. Waterbury. VT.

Soil Bioengineering for Upland Slope Protection and Erosion Reduction. Engineering Field Handbook, Chapter 19. 1992. US Department of Agriculture. Soil Conservation Service.

Vermont Streambank Conservation Manual. 1987. Department of Environmental Conservation. Waterbury. VT

For additional information, contact:

Water Quality Division
103 South Main Street. 10 North Building
Waterbury. Vermont 05671 -0408
(802)241-3770

Copied using scanner & OCR software by Kenyon F. Karl <railtrails@crosswinds.net>. Technical formulas and tables were omitted from this copy of the fact sheet to avoid the risk of serious OCR errors in the highly technical information. Unintentional errors are likely!

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