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THREATSWATER QUALITY Three natural factors in the watershed combine to produce the most significant water quality stressors: highly erodible soils, very intense rainfall events and a tendency for frequent and sometimes intense drought. Erosion also contributes to increased nutrient levels in streams due to the attachment of nutrients (particularly phosphorous) to soil particles that are transported into waterways. Drought conditions contribute to low flows that can cause low dissolved oxygen levels that stress aquatic organisms. Water quality data between 93 and 97 demonstrate some D.O. levels below the fish and wildlife standard of 5.0 mg/l in headwater streams, as well as turbidity approaching levels damaging to aquatic organisms in the lower portion of the watershed. All waters within the watershed are classified as Fish and Wildlife streams. (Troy) Double Bridges Creek demonstrates some high nutrient levels not related to wastewater treatment plant discharge. This combined with higher suspended solids and turbidity is primarily attributable to land use patterns and an abundance of unpaved roads. A poultry plant discharges to this stream. Nutrient levels in this subwatershed are two to three times higher than other parts of the watershed. Coliform bacteria was higher as well but not of great concern at this time. There are probably more water quality concerns in the Double Bridges Creek Watershed than in any other location within the watershed. (Troy) Coliform bacteria risks were minimal across the watershed. In all but two cases of high bacteria levels, the source of contamination was traced to livestock access or dead livestock in streams. Well contamination of nitrates and fecal coliform can be a problem within the watershed due to failing septic systems. Currently there is little data on this issue. Illegal dumping of household garbage, construction debris and animal carcasses is a common problem throughout the watershed. (Troy) Water quality in the Choctawhatchee-Pea Rivers watershed is generally good to very good. The Pea River Watershed has few water quality concerns aside from some low DO values on small streams and some sites with bacteria levels approaching the limit for full body contact. Both the Choctawhatchee mainstem and the Pea River show better water quality values in the upper basin due to a more forested land cover. The Pea river shows slightly better water quality values than the Choctawhatchee due to differences in land use patterns (90% forested vs. 70% forested) (Troy Center for Environmental Research) There has been evidence of increased agricultural activities such as chicken and hog farming, cultivation of sloping areas, and clear cutting of timber to the edge of streams. The Pea River has four wastewater treatment plant discharges, and there are five others into the Choctawhatchee River and its tributaries.(Corps 92) SEDIMENT A study in 83 concluded that the majority of the sediment loads to the river were coming from the upper Choctawhatchee and Pea Rivers. Though some erosion occurs naturally an increase in mechanized farming and other activities have increased normal sediment loads. As much as 323,790 tons of sediment was discharged to Choctawhatchee Bay according to the report. Land use patterns and their rate of erosion are as follows: cropland 8.3 tons/ac./yr., pasture/hayland 0.5, Forest Land 0.8, Other 2.3. However sources of erosion are highest from gullies, then cropland, then dirt roads, forest land, other uses, pasture, and streambanks. (NRCS) FLORIDA IMPAIRED STREAMS Much of the Lower Choctawhatchee and its tributaries in Florida are impaired for turbidity, nutrients, coliform and mercury. There is less water quality data available for the upper reaches of the system to assess impairment. For additional WQ data see Troy State 97 report. WATER QUANTITY Due to localized demand and dwindling aquifer reserves (primarily centered around the more urbanized areas such as Dothan), water development alternatives are being evaluated within the basin to meet future demands for water. The water needs of the watershed can not fully be met by ground water without pumping the major aquifers faster than they are naturally recharged. This will inevitably result in progressive aquifer depletion and ultimately, permanent aquifer damage. (GSA) A)
DROUGHTS Moderate drought conditions occur in the watershed on a 13-year cycle. (GSA) The basin has shown evidence of experiencing prolonged periods of hydrologic drought where improved rainfall allows recovery of agriculture and plant life but does not adequately replenish streams and aquifers. B)
FLOODS For the Pea River this was the single worst flood in the history of the region, the next largest occurring in March of 1929 and the third largest in July 1994. (Corps and GSA) Studies following the 1990 flood suggested improvements to the levees at Elba and Geneva but did not recommend the construction of a flood control dam on the Choctawhatchee or Pea Rivers. Water volumes may exceed 100 times the normal low water channel during flood events. (Corps) The Flood of 1929 ranks as one of the greatest ever experienced in the southeastern US. Rainfall at the center of the storm was 29.6 inches at Elba. (NRCS) The gage height at Newton recorded 42 feet. (GSA) For further information on Flood Conditions within the basin see NRCS and GSA documents. |
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