Intensive Survey of the Guadalupe River Segment 1806

CONCLUSIONS
The historical data and the results of this intensive survey indicate that
water quality is excellent throughout Segment 1806 of the Guadalupe River.
Diurnal dissolved oxygen levels remained above the 5 mg/L segment criterion
at all stations within the study area. The narrow ranges between dissolved
oxygen minima and maxima among the stations further indicate stability in
water quality and reflects the low primary productivity of the stream.
Nutrient levels were low through the river and suggest that either
phosphorus and/or nitrogen may be limiting growth of aquatic plants during
various seasons. The low levels of ammonia and absence of nitrite nitrogen
indicate that nitrification was not a contributing factor affecting the observed
nitrate and dissolved oxygen levels. Chloride, sulfate, total dissolved solids,
water temperature, fecal coliform, and pH levels generally conformed to
segment criteria. Benthic macroinvertebrate community structure reflected
low levels of secondary production and indicated clean water and stable
environmental conditions throughout the study area. Third Creek exhibited
the poorest water quality in the study area due to periodic discharges from
the City of Kerrville's wastewater treatment plant.
The water quality conditions of Guadalupe River Segment 1806 have been
documented and are likely to continue as long as no continuous sources of
wastewater enter the stream. The natural setting and excellent water quality
provides residents of the area with a highly valued recreational and aesthetic
resource. Partly as a result of this resource, the area is attractive to
tourists and population in the Kerrville area is rapidly growing. As the
population of the City of Kerrville continues to grow and effluent volumes
increase, the likelihood of a continuous discharge from its wastewater
treatment plant becomes more probable. The City of Kerrville has requested
amendment to its existing permit to allow upgrading of the present facility to
facilitate greater capacity and a continuous discharge to Third Creek. In
addition the cities of Kerrville and Ingram and the Upper Guadalupe River
Authority are jointty considering the option of building a regional wastewater
treatment plant near the Pear Creek confluence, to meet future wastewater
treatment needs of the area. Selection of the types of treatment facilities,
locations of effluent discharge points, and effluent treatment levels for the
proposed facilities will be essential to protecting existing water quality
conditions in Segment 1806 of the Guadalupe River.
Another intensive survey of Segment 1806 has been scheduled by the Texas
Water Commission. The survey will be conducted during low flow conditions
when a discharge from the City of Kerrville's wastewater treatment plant is
occurring. Data from the 1983 intensive survey and the proposed one will be
utilized by the Commission, through mathematical modeling processes, to
evaluate specific treatment levels for the City of Kerrville's wastewater
treatment plant and to write a waste load evaluation for Segment 1806.
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