During the year 2000, the Four Rivers region was assessed by a collaboration of agencies including the U.S. Army Corps of Engineers, U.S. Geological Survey, Tennessee Valley Authority, Kentucky Department of Fish and Wildlife Resources, U.S. Fish and Wildlife Service, ORSANCO, Murray State University, and Kentucky Division of Water. The data were assimilated and assessed by the Kentucky Division of Water as required by Section 305(b) of the federal Clean Water Act.   Streams were assessed for one or more designated uses that include primary contact recreation (swimming), secondary contact recreation, warmwater aquatic habitat, coldwater aquatic habitat, domestic water supply and outstanding state resource water.  In addition, fish tissue samples were collected and analyzed for contamination at various sites, based on evidence of sport fishing in the area or the possibility of toxicity problems from previously collected data.  Fish tissue is analyzed and advisories posted in areas where contamination poses human health threats.  For a list of the designation of uses of surface waters in Kentucky see 401 KAR 5:026.

There were approximately 1,045 miles of streams assessed in the region.  Of these, about 204 miles of streams were found to be not supporting one or more of their designated uses.  There were also about 338 miles partially supporting their supporting uses.  This leaves only about 503 miles, or about 48 percent, of the streams fully supporting designated uses.  Of those fully supporting streams, there were about 60 miles of water declared as “exceptional.”  Exceptional waters are those that have either a fish or macroinvertebrate community that is considered “excellent.”

In addition to the streams assessed, there were 13 lakes or reservoirs assessed for a total of 94,961 acres of water.  Two lakes, Hematite Lake and Swan Pond, were determined to be not supporting all of their designated uses. The remaining 11 lakes were all found to be fully supporting designated uses.  Numerous issues were identified during the assessment year, such as:

Population Growth and Urban Sprawl

The Four Rivers region is experiencing population growth and urban sprawl in the Hopkinsville, Murray and Paducah areas as well as in some of the smaller towns.  This development results in loss of green space and an increase in impervious surfaces such as rooftops, roads, driveways and parking lots.  Stormwater runoff from these impervious surfaces causes surges in stream levels and localized “flash flooding.”  In addition, the loss of trees, shrubs and grasses along the stream banks causes bank instability and erosion, which results in increased siltation. 

The loss of native habitat for many species of wildlife is also a concern.  As population growth and sprawl continues, habitat for wildlife diminishes.

The Four Rivers region is experiencing a loss of prime farmland to development and industrial uses.  While this increases the local economy and provides jobs for the short-term, it diminishes the ability to grow and produce animal and food products that will be needed in the future.  There is a need to practice using less productive soils and recycle old industrial sites for industrial uses. 

Nonpoint Source Pollution from Agriculture

Runoff from agriculture impairs more than 250 miles of streams in the Four Rivers region.  The main pollutants from agricultural runoff are nutrients, pathogens and silt/sediment.  The flow of rainwater over farming areas works as a vehicle for the movement of these pollutants into nearby streams or karst conduits.

The removal of riparian vegetation often associated with farming practices is one of the biggest factors affecting runoff of these pollutants.  Riparian or buffer zones help filter runoff from farm land.  If these are not present or are inadequate, the polluted runoff can flow directly into stream channels.  Also, as mentioned in the previous section on growth, the loss of riparian vegetation increases erosion from unstable stream banks.

Flooding

Since 1970 there have been more than 100 flood emergency declarations in the Four Rivers region.  As a result, floodplain management is an important issue in the Four Rivers region.  When development occurs in a floodplain, it causes several problems.   When the water rises, there is potential for lives and property to be lost.  The building of physical structures in the floodplain interferes with streambank stability, water quality, and downstream flooding.  All the counties in the Four Rivers region (with the exception of Lyon County) have floodplain management programs.  The purpose of a floodplain management program is to protect the floodplain and minimize threats to people and property. 

Hydromodification

Hydromodification impacted more than 140 miles of assessed streams in the basin.  Hydromodification is the alteration of the natural circulation or distribution of water by the placement of structures or other activities by humans.  Hydromodification in the basin can probably be traced back to early settlers who rerouted stream channels in order to establish larger parcels of land for agriculture.  Another early example would be the draining of wetlands to establish suitable farmland.  The extent of the success of early settlers is debatable and difficult to quantify.  In more recent times, the invention of earth moving equipment has allowed man to dam large streams, build floodwalls and levees and straighten stream channels.  All of these human alterations have taken place in the Four Rivers basin to some degree, either in the past or the present.

Old Landfills

There are several old landfills in the Four Rivers region that have never officially been closed, including multiple superfund sites still to be cleaned up.  It is feared these old landfills have the potential to leak and affect streams.

Loss of Wetlands

The Four Rivers region has 100,000 acres of wetlands.  Some are protected by Wildlife Management Areas, but most are privately owned.  These unprotected wetlands continue to be drained for industry and agriculture.

Untreated Sewage in Lakes

Lakes in the basin are being impacted by fecal coliform bacteria.  The bacteria are coming from houseboat dumping and failing septic systems around the lakes, as well as concentrated animal feeding operations upstream.  Although some progress has been made in this area, much work remains to be done.  Boat pump-out stations are provided at the major marinas on Kentucky and Barkley Lakes.