Clean water for cities is one of the region's most important products.
Water is the largest constituent of living organisms and a prerequisite for life. Concerns about water and aquatic resources in the Southern Appalachians began long before this assessment. The national forests in the region were established early in the 20th century primarily to protect the headwaters of major rivers from land uses that encouraged flooding, erosion, and stream sedimentation. Similarly, the Tennessee Valley Authority (TVA) was established to control disastrous flooding of the Tennessee River system and to improve navigation to enhance economic development.
Figure 75
Clean water for cities is one of the region's most important
products.
This report provides an overview of the physical setting, a summary of effects of human activities on aquatic resources, an assessment of water quality, an assessment of aquatic species, a brief summary of laws and regulations, and a brief discussion of water uses within the SAA. Three integration findings are discussed, and research needs identified during the assessment are listed.
High rainfall maintains year-long flows in an unusually dense network of streams. Stream density in the SAA region averages 12 feet of channel length (fig. 76) per acre of land. Natural lakes and impoundments cover nearly 870 square miles (fig. 77) of surface area.
Figure 76
Mean stream density is 12 channel feet per acre and very high
in some portions of the study area if all small mountain streams
were measured.
Figure 78
Major drainages in the Southern Appalachians flow into the
Chesapeake Bay, the Ohio River, the Atlantic Ocean, the Gulf of
Mexico (via the Alabama River), and the Mississippi River (via
the Tennessee River).
Human activities affect aquatic resources by altering the quality or condition of the water, altering stream channels, and altering adjacent riparian areas. Aquatic resources can be influenced by erosion, deposition of sediment, alteration of stream channels, and changes to the chemistry of water.
Examples of human activities that affect aquatic resources include: land development, road construction, mining, agricultural activities, and forestry operations.
People often alter the vegetative cover on the land to suit their needs. The distribution of land cover classes that are important to aquatic resource is highly uneven across ecological regions. Agricultural land dominates in the Ridge and Valley region, while forest dominates the Blue Ridge region. The distribution of land uses is an indicator (fig. 79) of the potential impacts on aquatic resources. Impacts from developed land and plowed fields are likely to be higher than those from forestry activities. Federal holdings, including national forests and national parks, are largely forested and, therefore, have fewer human influences than much of the rest of the study area.
Figure 79
Distribution of land use/land cover classes by ecological
region.
People often alter the land in ways that affect the flow of water. These hydrologic changes may be significant on a small watershed or at a stream site but rarely noticeable at the scale of a large watershed or river basin. When the hydrologic regime of a stream changes, the channel is altered to the new regime. Natural events, such as floods, droughts, and landslides can have similar or even greater hydrologic effects than human activities. Major changes in a stream channel system can include scouring during peak flows and transfers of sediment. Dams and their reservoirs change the hydrologic regime by replacing turbulent channel flows with slow movement of water through deep flooded lakes. The natural movement of sediment through the system is halted, and downstream channel erosion may be initiated.
Water quality can be affected by nonpoint and point source pollution. Nonpoint sources have diffuse places of origin such as agricultural fields, logging sites, roads, and abandoned landfills. Point sources are associated with identifiable conveyance systems such as pipes and industrial drainage channels.
Between 1982 and 1992, 23 counties in the region reduced potential soil erosion due to agricultural activities by more than 50 percent, while 8 counties had an increase of more than 50 percent. Human development can also increase soil erosion rates. The population of the Southern Appalachians grew by 19 percent between 1970 and 1980 and by 7 percent between 1980 and 1990. Construction of houses, service facilities, and roads for this growing population undoubtedly had adverse effects on aquatic resources.
About 3,000 point sources discharge treated wastewater into water bodies in the Southern Appalachians. The majority of sources with discharges greater than 1 million gallons per day (132 of 222) are municipal treatment facilities. The three industries with the largest number of point discharge sites are mining, textiles, and chemicals. These industries have 44 discharge facilities that are rated as major.
A total of 890 potential pollution sources in the Southern Appalachians are listed under the Comprehensive Environmental Resource Conservation Liability Act (CERCLA). Twenty-two sites are on the National Priorities List as Superfund sites, and 84 are either abandoned or closed landfills. At the time of this assessment, 170 active sanitary landfills, managed under current rules, were not on the CERCLA list. Mining, human development, and dams cause the largest hydrologic alterations in the region. Mining impacts on water quality are primarily in the Tennessee River basin and in southwestern Virginia.
The assessment of water quality in rivers and their tributaries is based on ability to support designated uses, such as fishing, aquatic life, swimming, and drinking water. The states are responsible for adopting water quality criteria to maintain the designated uses of streams and reporting biannually on the condition of streams and waterbodies.
In watersheds representing 75 percent of the river miles in the study area, over 80 percent of the river miles have water quality that partially or fully supports designated uses (fig. 80). The remaining miles of stream in these watersheds do not have suitable quality for current uses. Water quality is impaired on more than 20 percent of the stream miles in 15 watersheds. The Tennessee and Alabama river systems include most of the significantly impacted watersheds. In the study area, Virginia watersheds in the Chesapeake Bay drainage have the highest percentage of waterbodies meeting water quality standards for designated uses.
Figure 80
Over 80 percent of the streams have water quality that
supports designated uses such as fishing, swimming, and drinking
water.
Figure 81
Eutrophic lakes contain high concentrations of nutrients,
which promote growth of algae and deplete oxygen supplies.
(Mesotrophic indicates moderate amounts of dissolved nutrients;
oligotrophic indicates small amounts of dissolved
nutrients.)
Figure 82
Fish consumption advisories currently are in effect in various
places in the region because of contamination by toxic
chemicals.
Figure 83
Fifty-four percent of the stream miles are in areas that have
high sensitivity to acid deposition.
The waters of the Southern Appalachians support a large variety of aquatic life, and the adjacent riparian zones are equally significant to many other species. The status of every species in the SAA region could not be assessed, but it was possible to assess the status of some groups of species.
Threatened and endangered and special concern (TE&SC) species include threatened and endangered species that are listed by the U.S. Fish and Wildlife Service as required by the Endangered Species Act. Special concern species are those formerly identified as category 2 candidate species for U.S. Fish and Wildlife Service listing and those globally ranked by The Nature Conservancy as rare (G1, G2, or G3). Some 190 aquatic and semiaquatic TE&SC species in the SAA region have historical or current occurrence records on state Heritage Program lists. Of these, 62 are fish and 57 are molluscs. Of the 34 endangered species, 26 are molluscs and 7 are fish. The three areas with the greatest number of TE&SC aquatic species were: (1) the Powell and Clinch River drainages in Virginia and Tennessee; (2) the area around Knoxville and Oak Ridge, Tennessee; and (3) Monroe County, Tennessee. The Powell River drainage has been impacted by coal mining and associated acid mine drainage but remains a refuge for many TE&SC species. On the Tennessee River, water impoundments have adversely affected mussel species.
Individual states list 260 "other aquatic species" that are at risk in the study area. This list includes 97 fish, 25 mussel, 1 snail, 2 crayfish, 111 salamander, and 7 turtle species. In many cases, a species is at the edge of its range in an individual state. As a result, its numbers may be very limited in that state but large elsewhere. Other species are endemics that may be easily imperiled.
The native and introduced species of trout in the Southern Appalachians are of special interest to anglers (fig. 84). These fish require cold mountain streams and are seldom found in the streams of surrounding flatlands (fig. 85). About 39 percent of the SAA region is within the range of wild trout. About 70 percent of streams that are in the range for wild trout are on private land. For various reasons, wild trout species may not actually occur in all the streams within their range. Like most fish, trout are sensitive to acidic conditions. Almost 60 percent of potential wild trout streams in the SAA region are in areas that are highly sensitive to acidification. Another 27 percent are in areas that are moderately sensitive. Most of the highly sensitive streams are in the northern part of the study area. Hemlock woolly adelgids threaten streamside hemlocks, which are important components of the riparian ecosystems that support trout streams. Gypsy moths also may impact trout habitat by defoliating large areas of mountain watersheds.
Figure 84
Trout in the Southern Appalachians are of special interest to
anglers.
The Clean Water Act of 1972 and subsequent amendments provide the legal framework for the protection of aquatic resources. The Act's objective is to "restore and maintain the chemical, physical, and biological integrity of the nation's waters." In 1987, the Act reaffirmed the national goals for elimination of discharges of pollutants into navigable waters of the United States and, where attainable, water quality that provides for the protection and propagation of fish, shellfish, and wildlife. A further requirement of the Clean Water Act is the development of programs for control of pollution (non point source) that originates from diffuse sources such as agricultural fields and construction sites.
Under the Clean Water Act, the discharge of pollutants into waterbodies is regulated and limited through the National Pollutant Discharge Elimination System (NPDES). Water quality standards are implemented and enforced by the states and the EPA through the NPDES permit system. Water quality standards are implemented through discharge permits issued by EPA or delegated states. Currently, all states in the SAA area have NPDES permitting authority.
A nationwide permit program that regulates dredge and fill operations is administered by the U.S. Army Corps of Engineers. It is extensively used for regulation of activities in wetlands and navigable streams.
Nonpoint source pollution is controlled through the development and implementation of Best Management Practices (BMPs) for forest, agricultural, and developed land. An example of a BMP is seeding and mulching to stabilize newly constructed forest roads (fig. 86).
Figure 86
Best Management Practices are essential for controlling
non-point source pollution.
The last 8 years have been a turning point in water resource legislation and pollution control. Programs have been specifically designed to deal with nonpoint source pollution and toxics as well as point sources. Programs also have emphasized protection of national treasures such as the Great Lakes and Chesapeake Bay. The water pollution control program administered by EPA has been largely successful in reducing point source pollution. Many streams and lakes have gradually recovered from years of abuse and now support abundant aquatic life as well as swimming and other recreation activities. The design and use of BMPs have demonstrated that technology also can reduce nonpoint source pollution.
Figure 87
Water use increased steadily between 1950 and 1980, then began
to decline. (Source: US Geological Survey circular
#1081)
In comparison with water use in developed areas, water use on national forests is generally insignificant. The high-quality water that comes from national forest watersheds is of enormous value to cities downstream, however.
Where possible, aquatic resource assessment findings were integrated with findings from the atmospheric, terrestrial, and social/cultural/economic assessments. Some integrated findings were reported in chapters 2 through 6 of the Aquatics Technical Report. Although beyond the scope of the SAA, there are many more opportunities for integration of data and findings with those from the three other technical teams. Further integrated analyses will be simplified by data accessible through the Internet. This section briefly discusses several findings that are based on integrated data from two or more of the technical reports.
Wise, Dickenson, and Buchanan Counties in southeastern Virginia have large numbers of active mines (fig. 88). These counties are also in a region that has a high potential for adverse impacts due to atmospheric sulfate deposition (Atmospheric Technical Report). Because the historic and current mining activities in these counties have already impacted the water quality of several streams, it is not likely that the sulfate from continuing air deposition will result in further significant degradation (fig. 89). Past mining practices on other watersheds in the SAA area also have caused documented impacts that may mask some of the future impacts of atmospheric sulfate deposition.
Figure 88
Many active mines are located in the study area.
In this assessment, it was not possible to adequately estimate the impacts of increasing population on aquatic resources. We know that land covers which represent human activity (e.g., developed or barren, cropland, and pasture or herbaceous) already occupy more than 50 percent of the land area on many large watersheds (fig. 90). Very few large watersheds have less than 10 percent of their area in these land covers. Most of these areas are intensively used by humans, but some land is barren because of rock outcrops and some land with a herbaceous cover is in high-elevation balds and rhododendron beds where little human activity is occurring. Unfortunately, we could not separate some kinds of developed and undeveloped ecosystems in the data set.
Figure 90
Human activity occupies more than 50 percent of the land area
on many watersheds.
Figure 91
In many large watersheds, human activity has reduced forest
land cover in riparian zones to less than 60 percent.
Riparian habitat constitutes an estimated 2.3 million acres of the study area. For analysis, a riparian zone was assumed to be 100 feet on each side of streams and rivers. Of these acres, 69.8 percent are forested riparian habitats. Riparian areas are important habitat for wildlife and plants because these areas provide conditions and resources that are lacking in drier surrounding uplands, which may also be more subject to human activities such as logging, agriculture, or development. A total of 49 terrestrial plant and animal species from the SAA short list (Terrestrial Technical Report) are associated with seeps, springs, and streamside habitats. Of these species, 10 species are federally listed threatened and endangered, with 81 percent of these Element Occurrence Records (EOR) occurring on private lands. There are 24 viability concern species (equivalent to aquatic special concern species) associated with these habitats, with private lands containing 42 percent of the EOR occurrences, national forests 37 percent of the occurrences, and national parks 16 percent of the occurrences.
Many data gaps were identified during the aquatic resource assessment. Little or no data exist to address some important resource questions. In addition, the spatial distribution, timing, or quality of data collection severely limits the usefulness of data. These problems were translated into the monitoring needs and research opportunities listed below:
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