Water
 
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State of the river
Water Quality Index
October 2008

The month of October saw at least some rain throughout the basin, in the early and middle days of the month, though not enough to break the drought. The heaviest rains of 3-4 inches fell in Fayette and Washington Counties. Western Travis County also saw some significant amounts. Rainfall amounts were enough to have an impact on water quality, both good and not so good. Fall does appear to have made its way to Texas and the cooler nights’ effects can be seen in lowered water temperatures.  

Most of the upper basin, including lakes Buchanan, LBJ, Marble Falls and Travis and the San Saba and Pedernales Rivers received water quality ratings of excellent. The Llano River eked out a fair rating due to significant rainfall just prior to sampling, which caused a spike in bacteria. Water temperatures generally fell this month to the mid 70’s but Lake LBJ experienced the highest water temperature at 85° F. Dissolved oxygen levels were within an optimal range. Clarity was good when it wasn’t negatively impacted by heavy rains causing runoff and resulting in turbidity. Lake Travis came in with a visibility of 15 feet.
 
Downstream of Austin, the Colorado River was rated as excellent at Bastrop, Smithville, Columbus, Wharton and Bay City as all measured parameters were within optimal ranges for this time of the year. The Colorado River at La Grange received a “good” rating due to slightly elevated nutrient levels. October marks the end of irrigation season. Flows in the river are expected to decrease as irrigation releases are curtailed for the year. 

For information on a specific lake or river, see a link below:

Austin

Bastrop

Bay City

Columbus

La Grange

Lake Buchanan

Lake LBJ

Lake Marble Falls

Lake Travis

Llano River

Pedernales River

San Saba

Smithville

Wharton
 
 

Austin
Rating: Excellent
The Colorado River at Austin received an excellent rating in October. Water quality parameters were within optimal ranges for this time of year, including dissolved oxygen high enough for a healthy fish community. Bacteria levels were not a concern for contact recreation and nutrient levels were low. The water temperature was 73°F.

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The Colorado River at the 969 bridge at Bastrop.

Bastrop
Rating: Excellent
Water quality was rated excellent at the Colorado River at Bastrop. Dissolved oxygen levels were high enough to support a healthy fish community and nutrient levels were low. Bacteria levels were also low and therefore not a concern for contact recreation. The water temperature was 73°F and water clarity was almost 2 feet.

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Bay City
Rating: Excellent

The Colorado River at Bay City's Riverside Park.
Water quality for the Colorado River at Bay City was rated excellent with dissolved oxygen levels high enough to support a healthy fishery. Nutrient levels were low. Bacteria levels were also low and therefore not a concern for contact recreation.  The water temperature was
77° F and clarity was almost 2 feet.

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Columbus
Rating: Excellent
The Colorado River at Columbus was rated excellent. Dissolved oxygen was high enough to support a healthy fishery.  Nutrient levels were low. Bacteria levels were low and therefore not a concern for contact recreation.  The water temperature was 74°F.

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La Grange
Rating: Good
The water quality on the river at La Grange was rated good. Dissolved oxygen was high enough to support a healthy fishery. Though nutrient levels were slightly elevated due to wastewater facility discharges, bacteria levels were not a concern for contact recreation. The water temperature was 75°F and clarity was 1.5 feet.

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Lake Buchanan
Rating: Excellent
Water quality at Lake Buchanan was excellent, with dissolved oxygen levels high enough for a healthy fishery. Bacteria levels were low and not a concern for swimmers. Nutrient levels were low and water clarity was 4 and ½ feet. The water temperature was 75°F.

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Lake LBJ
Rating: Excellent
Though the water temperature was the warmest in the basin at 85°F water quality measurements were rated excellent at Lake LBJ. Dissolved oxygen was optimal for this time of year.   Bacteria and nutrient levels were low and therefore not a concern for contact recreation. Water clarity was 5 feet this month.

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Lake Marble Falls
Rating: Excellent
Water quality parameters were within optimal ranges for this time of year, including dissolved oxygen high enough for a healthy fish community. Bacteria and nutrient levels were low and therefore not a concern for contact recreation. The water temperature was 76°F and clarity was 3.5 feet.

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Lake Travis
Rating: Excellent
Water quality parameters were within optimal ranges for this time of the year. Dissolved oxygen was high enough to support a healthy fish community. Nutrients and bacteria levels were low and therefore not a concern for contact recreation. The water temperature was 78°F and water clarity was a clear 15 feet.

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Llano River
Rating: Fair
Water quality on the Llano this month was impacted by significant rainfall just prior to sampling Dissolved oxygen was high enough to support a healthy fishery and nutrient levels were low, but because bacteria was high enough to be a concern for contact recreation, the Llano River only received a fair rating. The water temperature was 76°F.

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Hammets Crossing on Pedernales River
Hammett's Crossing on the Pedernales River is one of 14 sites monitored each month.

Pedernales River
Rating: Excellent
Water quality was rated excellent as readings were within optimal ranges established for this time of the year. Dissolved oxygen was high enough to support a healthy fishery. Bacteria and nutrient levels were low and therefore not a concern for contact recreation. The water temperature was about
83°F.

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San Saba River at Risien Park
Rating: Excellent
The San Saba River was rated excellent this month as all water quality parameters were within optimal ranges. Dissolved oxygen was high enough to support a healthy fish community. Bacteria and nutrient levels were low and therefore not a concern for contact recreation. The water temperature was 72°F.

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Smithville
Rating: Excellent
Water quality measurements were within optimal ranges for this time of the year for the Colorado River at Smithville.  Dissolved oxygen levels were high enough to support a healthy fish community. Nutrient levels were within the norm. Bacteria levels were low and therefore not a concern for contact recreation. The water temperature was 75°F.

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Wharton
Rating: Excellent
Water quality for the Colorado River at Wharton was rated as excellent. Dissolved oxygen levels were high enough to support a healthy fishery. Nutrient levels were low. Bacteria levels were also low and therefore not a concern for contact recreation.  The water temperature was 74°F.

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MORE RESOURCES
READING THE RATINGS

The water quality index is issued monthly by LCRA to characterize the general water quality of the rivers, tributaries and Highland Lakes. The index is based on six parameters: dissolved oxygen, nitrogen, phosphorus, temperature, total dissolved solids, and fecal coliform bacteria.

Here's a primer on what the ratings mean:

  • Excellent: All water quality parameters measured are within optimal ranges. The water quality supports all designated uses and is esthetically pleasing and suitable for swimming.
  • Good: At least four of six parameters are within the acceptable ranges. The water quality supports most designated uses and is esthetically pleasing and suitable for swimming.
  • Fair: Half of the parameters are not within acceptable ranges or bacteria levels exceed state standards. Water quality supports noncontact recreational uses but may not be suitable for swimming.
  • Poor: At least four of the six parameters, including fecal bacteria, are outside acceptable limits. Contact recreation (such as swimming) is not recommended. To date, major flood events have been the primary reason for a poor rating.