Although settlers once described the Town Branch corridor as a region thick with forest, native cane breaks, wildlife, and clear, clean water, it is now listed on the KPDES Storm Water Monitoring Report as one of the most polluted streams in the state.  Excess nutrients from fertilizer, fecal coliform bacteria from human and animal wastes, hazardous storm water runoff, loss of native riparian vegetation, soil erosion, and an oozing landfill have all contributed to the deterioration of the ecology of the stream corridor.   The Town Branch has been listed as an impaired waterway by the state and federal governments because of excessive nutrient levels and too litle oxygen, and has consistently failed to meet standards for safe swimming.  Aquatic life in the creek has also become degraded for these reasons.(6)

Non-Point Pollutant Sources
The non-point pollutant sources within the watershed are numerous, and their collective dangers are well documented.  Manure, commercial fertilizer, herbicides, pesticides, fecal wastes, and urban runoff from roads and parking lots are common pollutants to the Town Branch that either deplete the water of oxygen, or kill aquatic organisms directly and accumulate in the food chain.  Soil sediment from exposed earth or streamside erosion, and loss of riparian vegetation due to urbanization cause thermal pollution and further degrade aquatic habitat.   The greatest direct cause of thermal pollution is likely the Town Branch Sewage Treatment Plant, which as a known point of discharge, can be further mitigated before entering the stream channel.

Role of Riparian Buffers
The most well known and effective mitigation technique of the above pollutants is the creation or maintenance of a naturally vegetated riparian buffer.  Research has shown that streamside forests and other naturally-vegetated riparian areas act as living filters to intercept and absorb these pollutants before they enter the water channel.  The effectiveness of the filter is influenced by the width and nature of streamside vegetation, the nature of discharge flow, and soil permeability.(7)  Generally, the wider the buffer, the longer the detention time, and the more diffused the infiltration, the better.  As mentioned earlier, streamside vegetation also serves as wildlife corridors for species habitat, movement, and dispersal, thereby protecting the biodiversity of the region. 

Status of Riparian Buffers along the Town Branch
Most of the naturally occurring riparian forest within the urban service boundary has been lost.  That which exists is very narrow and often does not provide the filter functions provided by wider buffers intercepting surface flow.  Most of the runoff received by the stream during periods of rainfall is transported via underground pipes and culverts.  Urban streamside vegetation, however, does play an important role in providing protection from stream bank erosion (roots hold the soil in place during high velocity flows), and in providing shade to keep water temperatures lower during warmer months.  Areas devoid of such vegetation should be planted to achieve the greatest width possible. 

Areas downstream, however, do benefit from greater buffer widths, although these corridors are not continuous.  Existing buffers should be protected, and where possible enlarged and connected. Delineation of the existing tree canopy is provided in analysis maps contained on the following pages.

Sensitive Habitat
It is estimated that less than 10% of Fayette County’s pre-settlement vegetation remains and is continually threatened by ongoing development.(8)  Areas with significant vegetation have been identified by the Nature Conservancy and are noted in the following sections.  If riparian corridors are established for water quality control, effective monitoring of the remaining precious native vegetation (identified for sensitivity, rarity or endangered status) must take place to ensure these areas are not degraded or lost.  Management of these areas should be structured in accordance with restoration guidelines directed by the County Conservation Plan and government planning officials.  The Urban-County Government has been very active in coordinating volunteer riparian reforestation efforts.

Point-source Pollution
While non-point source pollutants contribute a great deal to the degradation of the stream, point source pollutants are also significant. The closed city landfill leaches pollutants directly into the Town Branch (identification of which exceeds the scope of this study, and begs for further investigation).  In addition, over 31 permitted discharges of pollutants can be found within the watershed, along with over 500 sites involved with the use, manufacture, treatment, transport, or disposal of toxic chemicals and hazardous waste.  Approximately 200 sites are considered to generate hazardous stormwater.(9) 

Although these land uses contribute to the degradation of water quality, they are known (and regulated) pollutant point sources that can be contained for preliminary treatment before entering the stormwater system, and can be subject to further regulation by an act of legislation. At present, Lexington needs to be able to assume primary responsibility for improving the water quality of the Town Branch, not the federal or state government.  

Although the above ecological hazards are serious issues, conditions will not improve unless citizens take interest and initiative in the cause.  This means that Lexingtonians need to show support for local environmental officials that are trying to establish riparian corridors, as well as support the enforcement or creation of legislation that will reduce pollutants at their source. Specific environmental design recommendations for the greenway will be discussed in the following sections.