When stakeholders first become involved in regional conservation planning they often face an array of new topics. A fundamental understanding of technical topics involved in the HCP is vital to effective individual participation the process. As the HCP projects move forward, this page will be updated with background on the various components of the HCP.  If you are a Cumberland HCP stakeholder and have a topic you would like the Team to cover on this page, contact us!

Topics:

• What is a watershed?
• Stream Order
• Water Quality
• Hydrology
• Point and Nonpoint Pollution
• Stormwater
• Turbidity and Sediment

What is a watershed?

Wherever you are…you are in a watershed!  A watershed is the area of land from which water flows to a common destination including any stream, river, lake or ocean. Because a watershed is the land area that drains to a particular point, the size of a watershed depends on the number of tributaries that are involved.  Watersheds are also nested within each other.  For example, the Daddy’s Creek Watershed is within the Obed River Watershed, which is within the Tennessee River Watershed, which is part of the Ohio River Watershed, which is part of the Mississippi River Watershed, and, ultimately, the Gulf of Mexico Watershed! The Environmental Protection Agency Locate Your Watershed database can be used to locate the watershed in which you live.

Through the collection and movement of rainwater and snowmelt, watersheds provide many services that we depend on – flood protection, clean drinking water, fishing, and recreation.  Healthy watersheds are critical to ensure that these services are provided long-term.Watersheds have two characteristics key to their function – what is the land use and how does the water move?  In natural and rural settings, most precipitation falls on forests, pastures, etc. that allow a large portion of the water to soak into the soil. Urban watersheds work a little differently. As land is covered by houses, businesses, roads, sidewalks, and other “impervious surfaces,” precipitation is no longer able to soak into the soil.  Water in urban areas is typically moved to a stream in concrete gutters and storm drains. During a rain event, nearby streams and rivers receive a much larger amount of runoff much more quickly than if the area had less impervious area.  This can lead to erosion of stream banks and other water quality problems. Urban watersheds have additional water quality challenges that come about because more people means more cars and car fluids, more lawns and lawn chemicals, more houses and septic tanks.  These “nonpoint” sources of pollution do not necessary mean that an urban watershed will be unhealthy, but that additional effort is needed to ensure that water leaving an urban watershed is able to support the needs of aquatic organisms and humans.

Watersheds such as the Obed and Emory provide the Plateau region with a clean drinking water supply, recreational opportunities for visitors, and habitat for many species. Maintaining the health of these watersheds is important in order to preserve these valuable natural resources for future generations.

More information about watersheds:

• “Why Watersheds?” (Center for Watershed Protection)
• Center for Watershed Protection Watershed Resource Library
• Urban Watershed Manuals, Center for Watershed Protection
• USGS Science in Your Watershed
• Landowner’s Guide to Streambank Stabilization (TDEC)
• Wetland Fact Sheets (EPA)
• Biological Indicators of Watershed Health (EPA)
• USGS Water Education
• "Water on the Web" Educational Site
  

Stream Order Conservation measures in the Forest Resources HCP refer to “stream order.”  Stream order is a method of identifying the location of a stream relative to the other creeks, streams, and rivers within the same drainage. The stream order system was first developed by Arthur Strahler over 50 years ago.  The smallest perennial streams in a system are labeled “first-order” streams.   Perennial streams are those which flow year-round.  Ephemeral streams, those which regularly go dry during part of the year, are typically not included in the Strahler stream order classification system.  In the Forest Resources HCP, ephemeral streams that feed first-order streams are labeled as “zero-order” streams. Stream order numbers increase as more tributaries join together downstream. When two first-order streams come together, they form a second-order stream. When two second-order streams come together, they form a third-order stream, and so on to larger rivers such as the Mississippi (tenth order) or Ohio (eighth order). Stream order provides a shorthand description of the size and strength of a waterbody, which is directly related to the availability of aquatic species habitat. A different mix of fish, mussels, and plants can live in larger rivers like the Tennessee than can live in a smaller tributary such as Daddy’s Creek.

Water Quality

Water quality is a term used to describe the chemical, physical, and biological characteristics of water with respect to its suitability for a particular purpose. For example, water that is perfectly good to wash a car may not be clean enough to drink. When we talk about “water quality” in the HCP, we are typically looking at the water conditions relative to the needs of aquatic plants and animals (see Covered Species). 
The quality of water is determined by making measurements in the field or by taking samples of water, suspended materials, bottom sediment, or plants and animals, and sending them to a laboratory for physical, chemical and microbiological analyses. For example, acidity (pH), color and turbidity (a measure of the suspended particles in the water) are measured in the field. The concentrations of metals, nutrients, pesticides and other substances are measured in the laboratory.
Another way to obtain an indication of the quality of water is biological testing  - using the water directly to grow aquatic plants and animals. This type of test determines if the water or the sediment is toxic to life forms or if there has been a fluctuation in the numbers and kinds of plants and animals. Some of these biological tests are done in a laboratory, while others are carried out in the stream or lake.
To determine water quality, scientists measure and analyze characteristics of the water such as temperature, dissolved nutrients (nitrogen and phosphorus), dissolved metals, dissolved minerals, number of bacteria, and turbidity (i.e. cloudiness of the water). Selected characteristics are then compared to numeric standards and guidelines and species needs to decide if the water is suitable for a particular use.

The most common dissolved substances in water are minerals or salts that, as a group, are  referred to as dissolved solids. Dissolved solids include common constituents such as calcium, sodium, bicarbonate, and chloride; plant nutrients such as nitrogen and phosphorus; and trace elements such as selenium and chromium. In general, these common constituents are not considered harmful to human health, although some can affect the taste, smell, or clarity of water. Plant nutrients and trace elements in water can be harmful to human health and aquatic life if they exceed standards or guidelines. Plant nutrients can also lead to excessive algae growth, which can have significant negative effects on aquatic life. Dissolved oxygen is another key component of water quality. Adequate oxygen levels in water are a necessity for fish and other aquatic life. Many factors such as temperature, photosynthesis rates of aquatic plants, and temperature affect the levels of dissolved oxygen in a stream or river.

Both natural processes and human activities affect water quality. As rainwater or snowmelt moves over the ground, it dissolves material from rocks, soil, plant material, and can react with microscopic organisms.  These processes change the water’s chemical and physical composition.  Some of these are changes we can see (such as an increase in sediment suspended in the water causing it to look muddy) but other changes can only be detected through field or laboratory analyses (such as an increase in bacteria).  Human activities such as discharge of treated sewage or runoff from lawns, roads, parking lots, and other developed areas also has an influence on water quality.  See the “Stormwater,” “Point and Nonpoint Pollution,” and “Turbidity” sections on this page for more information.
More information about water quality:

• Water Quality Primer (USGS)
• Ground and Surface Water Terminology
• Water Quality Fact Sheets
• Water Resource Primer
• Glossary of Water Quality Terms

Hydrology

Hydrology is the science that encompasses the occurrence, distribution, movement and properties of water. There are many pathways the water may take in its continuous cycle of falling as rainfall or snowfall and returning to the atmosphere. It may be evaporated directly from vegetation or the land surface or flow across the landscape into streams and rivers.  It may soak through the soil into groundwater reservoirs (aquifers), or be taken up by growing plants or resurface in a well or spring. The process of precipitation, movement through the surface-groundwater system, and evaporation back into the atmosphere is called the hydrologic cycle.
The primary components of the hydrologic cycle are rainfall, evaporation, transpiration, infiltration (water soaking into the soil), runoff, and condensation.

A large portion of the rain that falls is returned to the atmosphere by evaporation and by transpiration from plants. Evaporation and transpiration together are called “ evapotranspiration.” Water that is in the soil near the land surface can return to the atmosphere through evaporation. Transpiration refers to the return of water to the atmosphere directly from plant tissue. Evapotranspiration is affected by several variables such as the amount of moisture in the air (humidity), the amount of sunlight, wind, and temperature.

Part of the rainfall that reaches the land surface infiltrates the soil, where it gradually percolates
downward until it reaches the aquifer. An aquifer is a layer or a combination of several layers of

More information about hydrology:

• Hydrologic Cycle Graphic
•  Simplified Version of the Hydrologic Cycle
• Nitrogen and the Hydrologic Cycle
• Aquifers on the Cumberland Plateau (USGS)

Point and Nonpoint Pollution

“Pollution” refers to any substance that has a negative effect on water quality and health of aquatic life.   As broad as the definition are the diversity of sources.  Generally, pollution comes from either a point source or nonpoint source.  Point source pollution comes from a single source, such as a wastewater treatment plant. This is also called “effluent.”   The Clean Water Act restricts how much and what kind of pollutants can be disposed of in rivers and lakes. While this has not eliminated effluent from entering our waters completely, it has reduced what once was the nation’s biggest source of water pollution.
Unlike point source pollution from industrial and sewage treatment plants, nonpoint source pollution comes from the cumulative effect of everyday activities within a watershed.  As runoff moves, it picks up natural and human-made pollutants, finally depositing them into streams and rivers, and even our underground sources of drinking water.   Common nonpoint pollutants include:

• Excess fertilizers, herbicides, and insecticides from residential areas;
• Oil, grease, and toxic chemicals from streets and parking lots;
• Sediment from improperly managed construction sites, improper forestry practices, and eroding streambanks;
• Road salt; and
• Bacteria and nutrients from livestock, pet wastes, and faulty septic systems.

Nonpoint pollution affects urban and rural areas alike, although the effects tend to be more acute in urban areas. For example, construction occurs across the landscape.  If not managed properly, significant volumes of sediment can wash away from construction sites, muddying local waterways and filling streambeds with silt, impairing the ability of fish like the Blackside Dace to feed and reproduce. When fertilizer is applied excessively or just prior to a rainstorm, it can wash off lawns into a nearby stream if in a rural area or into a stream via a city’s storm sewer system. Once in the water, fertilizer has the same effect on algae as it does on lawns - it makes it grow! Overgrowth of algae can have devastating effects on a stream, consuming oxygen in the water and suffocating fish and other aquatic wildlife. This is called eutrophication.
Because of its close association with a rainfall or snowmelt event, nonpoint source pollution is often intermittent and difficult to identify, isolate and control.  However, best management practices can be implemented to manage nonpoint pollution and decrease its effects on aquatic life.

More information about point and nonpoint pollution and how you can help:

• Nonpoint Source Pollution Primer
• Household Management of Nonpoint Source Pollution
• Dos and Don'ts for Household Nonpoint Pollution Management

Stormwater

(partial text courtesy of the Obed Community Watershed Association)

When a rainfall event occurs, several things can happen to the water – infiltration into the soil, uptake by plants, evaporation back into the atmosphere, or runoff over the land surface.  “Stormwater” refers to water that falls as rain (or snowmelt) that runs off the land surface. 
Stormwater discharge is generated by precipitation.  The quality of runoff is affected by a variety of factors and depends on the season, local meteorology, geography and upon activities which lie in the path of the flow. Urbanization causes significant changes in stormwater runoff characteristics. As the natural landscape is cleared, graded, and covered with buildings and parking lots, rainwater can no longer filter into the soil to become groundwater. As a result, more rainwater enters streams, and it enters more quickly.

Although stormwater discharge occurs in both rural and urban areas, in rural areas a much large proportion of rainfall soaks into the ground.  In urban areas, where much more of the landscape is paved (“impervious”), a similar rainstorm will generate significantly more runoff than in a rural area.  Many research studies have confirmed a clear relationship between an increase in impervious cover and negative impacts to aquatic systems.

The most obvious consequence of increased stormwater is flooding.  However, significant water quality impacts are associated with stormwater as well. As it flows across paved surfaces, stormwater picks up pollutants and debris and carries them to stream. This increased volume and rate of runoff increases erosion and formation of gullies in upland areas, increases scour in streams and erosion of streambanks, increases sediment deposition in lower areas, degrades water quality, causes more frequent flooding, and negatively effects stream ecology.

Stormwater runoff accumulates pollutants such as oil and grease, chemicals, nutrients, metals, bacteria, and sediment as it moves across the land.  Transported soil clouds the waterways and interferes with the habitat of fish and plant life. Nutrients such as phosphorus and nitrogen can promote the overgrowth of algae, deplete oxygen in the waterway and be harmful to other aquatic life. Toxic chemicals from automobiles, sediment from construction activities and careless application of pesticides, herbicides and fertilizers threaten the health of the receiving waterway and can kill fish and other aquatic life. Bacteria from animal wastes and malfunctioning septic systems can make streams unsafe for wading, swimming and aquatic life. With more water running directly into streams instead of infiltrating into the soil, less groundwater is available to feed the stream during times of drought.

Although the negative effects of stormwater are widespread, impacts to both man-made and natural systems can be managed through careful management, maintenance, and planning to mitigate existing and future problems. Stormwater runoff is not treated by sewage and wastewater treatment plants in the Cumberlands.  Pollutants in storwmater are most effectively treated at the pollutant's source by employing best management practices, or "BMPs." Stormwater BMPs have two purposes – both to improve the quality, and decrease the quantity of stormwater runoff. BMPs are structural (such as a storwmater retention pond that filters our pollutants), vegetative (such as a grassy roadside ditch), or operational (grading as little of a site as possible during construction). BMPs help break the connection between increasing impervious cover and negative stream health.  The BMP page has more information about ways to manage the impacts of stormwater on aquatic ecosystems.

More information about stormwater:

• North Carolina Dept. of Environment and Natural Resources Stormwater Page
• University of Tennessee Municipal Technical Advisory Service Stormwater Online Library
• TDEC Municipal Stormwater Permitting Program
• EPA Stormwater Best Management Practices Database
• Stormwater Quality Primer

Turbidity and Sediment

Turbidity is a water quality parameter that refers to water clarity. The general rule is: the cloudier the water, the greater the turbidity. Silt (sediment), phytoplankton (algae), bits of decaying vegetation, and sewage are common solids that are suspended in the water (called TSS = total suspended solids).  Turbidity is a measure of the total suspended solids plus the degree to which the water is stained from dissolved organic material. Turbidity measurements are expressed as Nephelometric Turbidity Units, or NTUs.  Both suspended solids and water color contribute to the effects of turbid water on aquatic life.

The algae grow in the water and the detritus comes from dead algae, higher plants, zooplankton, bacteria, fungi, etc. produced within the water, and from watershed vegetation washed in to the water. Sediments are a natural part of streams and other water bodies and even the most pristine streams in undeveloped watersheds will run muddy during high flows. However, excessive sedimentation in streams and rivers is considered to be the major cause of surface water pollution in the U.S (38% of stream miles) followed by pathogens at 36%, and nutrients at 28%. Sediment is a leading source of impairment to lakes, ponds, and reservoirs. Sediment comes largely from shoreline erosion, watershed erosion, and resuspension of bottom sediments (see the “Stormwater” section of this page for more information).
Increased turbidity affects a stream and the organisms that live in it in many ways.  Suspended solids reduce the amount of light available for aquatic vegetation to grow by photosynthesis. Reduced plant matter means less food and habitat for herbivorous organisms such as snails, insects and juvenile fish. Reduced clarity also interferes with the ability of visual insect and fish predators to find their prey and may also impair reproduction when visual cues are a part of courtship and mating.

Fine particulate sediment can also have purely mechanical effects by clogging sensitive fish and insect gills and abrading soft tissue. As filter feeders, mussels like the purple bean and Cumberland elktoe found in Cumberland streams are particularly sensitive to the physical clogging effect of excess suspended sediment.  Growth rates, disease resistance, and reproductive success in fish like the Blackside Dace may be reduced by excess sediment. As particles of silt, clay, and other organic materials settle to the bottom, they can suffocate newly hatched larvae and potentially interfere with particle feeding activities. Settling sediments can fill in spaces between rocks which could have been used as habitat for the small critters that feed larger fish. Reduced light penetration can also prevent various organisms from seeing their food, their preys and predators, their mates and offspring. This is true whether increased turbidity is caused by natural or unnatural events.
Turbidity can also increase water temperature because suspended solids darken the water and absorb more heat from sunlight. Warm water holds less oxygen than cold water, so oxygen levels can decrease in addition to the direct effects of high water temperatures on cool-water adapted native species. The removal of streamside vegetation also contributes to elevated temperatures.
Elevated turbidity not only affects aquatic life.  Streams and rivers used for drinking water requires additional (and more expensive) filtration as turbidity increases.  Cloudy water also tends to be less aesthetically appealing.

Simple measures such as silt fencing and settling ponds can help control turbidity.  Compared to excess nutrients and heavy metals, turbidity is one of the easier water quality pollutants to control. See the Best Management Practices page for more information.