Monthly Water Quality Report

Monthly Water Quality Report
Current Water Quality Conditions
April 2012

The month of April brought warmer air and water temperatures and healthy dissolved oxygen levels throughout the Lower Colorado River Basin. Seven monitoring sites received excellent water quality scores, (the San Saba, Llano and Pedernales rivers, Inks Lake, and lakes LBJ, Marble Falls and Travis). Four locations impacted by a reduction in fresh inflows, reported fair conditions due to high nutrient measurements (the Colorado River at Austin, Bastrop, Smithville and La Grange). Lake Buchanan earned a good score, and further downstream, the river at Columbus, Wharton and Bay City also earned good ratings due to slightly elevated nutrients. Bacteria was within acceptable ranges this month.

All In the Highland Lakes area, the San Saba, Llano and Pedernales rivers were rated excellent this month. Inks Lake, lakes LBJ, Marble falls and Travis all earned excellent scores with optimal water quality measurements. Dissolved oxygen readings were ideal for healthy aquatic life, and bacteria and nutrients were low. Lake Buchanan’s good score was influenced by a slightly elevated nitrate measurement. This monitoring location, netting a five inch rain the week before, also reported the lowest water temperature of 62°. River transparency was greater than the total depth on the Llano and the Pedernales rivers at about one foot. San Saba’s river transparency was just under one foot. The Highland Lakes’ visibility was relatively uniform this month: Three feet at Inks Lake, a very clear five and a half feet for Lake Buchanan, just under six feet at Lake Marble Falls and seven feet at Travis. Water temperatures were in the seventies, with the exception of Lake Buchanan (see above) and 69° on the Pedernales.

Starting with the Colorado River at Austin, ratings were fair at Austin, Bastrop, Smithville and La Grange. These areas saw high nutrients due to wastewater dominant flows in this stretch of the river, though bacteria was low and dissolved oxygen was ideal for sustaining healthy fish populations. Slightly elevated nutrients at the Colorado River at Columbus, Wharton and Bay City netted these locations good ratings as other water quality determinants were good. River transparency at Austin was greater than the total depth at the sampling location, one and a half feet. The Colorado River at Bastrop reported just over a foot and a half and Smithville and Columbus, one foot of visibility. Columbus, Wharton and Bay City’s river transparency reports were all less than one foot. Water temperatures were in the seventies in the lower basin and the warmest temperature came in at Bastrop, 81°.

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

Austin

Bastrop

Bay City

Columbus

Inks Lake

La Grange

Lake Buchanan

Lake LBJ

Lake Marble Falls

Lake Travis

Llano River

Pedernales River

San Saba

Smithville

Wharton

Austin Water Quality Rating

	Colorado River at Montopolis Bridge in Austin
The Colorado River at Austin was rated fair in April. Dissolved oxygen was sufficient to maintain a healthy fish population. Bacteria levels were low. Nutrient levels were slightly elevated, as fresh inflows were somewhat limited. The water temperature was 78°F. River transparency was greater than the total depth at this location, one and a half feet.
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Bastrop Water Quality Rating

	Colorado River at Bastrop's Lost Pines
The Colorado River at Bastrop was rated fair in April. Dissolved oxygen levels were high enough to support a healthy fish population. Bacteria was low but nutrients were elevated, likely because river flows were effluent dominant. The water temperature was the warmest in the basin at 81°F. River clarity was about one and a half feet.
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Bay City Water Quality Rating

	Colorado River at Bay City's Master Naturalist Birding Center
The Colorado River at Bay City scored a good water quality rating this month. Dissolved oxygen was supportive of healthy aquatic life. Bacteria levels were low. Nutrients were elevated and will continue to be monitored closely. The water temperature was 77°F. Transparency was one half foot.
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Columbus Water Quality Rating

	Colorado River at Columbus
The Colorado River at Columbus scored a good rating in April with measurements typical for this stretch of the river and time of year. Dissolved oxygen was at a level supportive of healthy fisheries. Bacteria was low. Nutrients were slightly elevated though not atypical for this location. The water temperature was 78°F and transparency was just under a foot.
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Inks Lake Water Quality Rating

	Inks Lake at Inks Lake State Park
Inks Lake received an excellent score in April. All tests revealed ideal water quality measurements. Dissolved oxygen was supportive of a healthy fish community. Bacteria levels were low. Nutrients were also low. The water temperature was 73°F. Lake visibility was three feet.
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La Grange Water Quality Rating

	Colorado River in La Grange
The Colorado River at La Grange earned a fair rating this month. While dissolved oxygen was sufficient to maintain a healthy fish population and bacteria levels were low, nutrients were elevated due to effluent dominant flows The water temperature was 79°F. River clarity was one foot.
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Lake Buchanan Water Quality Rating

	Lake Buchanan at Burnet County Park
This month Lake Buchanan scored a good rating. All water quality parameters were acceptable for this time of year. Dissolved oxygen levels were high enough to maintain a healthy fish population. Bacteria levels were low but nutrients were slightly elevated. The water temperature was the coolest in the basin, 62°F. Lake visibility was five and a half feet.
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Lake LBJ Water Quality Rating

	Lake LBJ at Camp Champions
Lake LBJ received an excellent water quality rating in April. All water quality parameters were optimal for this time of year. Dissolved oxygen was high enough to maintain healthy aquatic life. Bacteria levels were low. Nutrients were also low. The water temperature was 75°F. Lake visibility was five and a half feet.
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Lake Marble Falls Water Quality Rating

	Lake Marble Falls at Lakeside Park
Lake Marble Falls earned an excellent rating in April with all water quality parameters at optimal levels. Dissolved oxygen was high enough to maintain a healthy fish population. Bacteria levels and nutrients were low. The water temperature was 76°F. Lake transparency was five feet.
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Lake Travis Water Quality Rating

	Lake Travis at Mansfield Dam
Lake Travis’ rating was excellent in April with optimal water quality measurements for this time of year. Dissolved oxygen was supportive of a viable fishery. Bacteria levels and nutrients were low. The water temperature was 70°F. Lake transparency was seven feet.
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Llano River Water Quality Rating

	Llano River at Scott’s Slab
This month the Llano River scored an excellent rating. All water quality parameters were optimal for this time of year. Dissolved oxygen levels were high enough to maintain a healthy fish population. Bacteria levels were low. Nutrients were also low. The water temperature was 78°F, the warmest in the upper basin. Transparency was greater than the total depth at this location, one and a half feet.
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Pedernales River Water Quality Rating

	Pedernales River at Pedernales State Park
The Pedernales River netted an excellent score this month. All water quality measurements were at ideal levels. Dissolved oxygen was high enough to sustain healthy aquatic life. Bacteria levels were low. Nutrients were also low. The water temperature was 70°F. River transparency was greater than the total depth, one foot.
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San Saba River Water Quality Rating

	San Saba River at Maxwell's Crossing
The San Saba River earned an excellent score for the month of April. All water quality tests revealed ideal conditions. Dissolved oxygen was supportive of healthy aquatic life. Bacteria and nutrients were low. The water temperature was 73°F and transparency was one foot.
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Smithville Water Quality Rating

	Colorado River at Hwy 95 in Smithville
The Colorado River at Smithville netted a fair water quality rating in April. Dissolved oxygen readings were sufficient to sustain a viable fishery. Nutrients were elevated because of wastewater dominance, but bacteria levels were low. The water temperature was 80°F. River transparency was a just over one foot.
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Wharton Water Quality Rating

	Colorado River at Riverfront Park in Wharton
The Colorado River at Wharton earned a good water quality score in April. Dissolved oxygen measurements were high enough to sustain a healthy fishery, and bacteria levels were low. Nutrients were slightly elevated though not unusual for this stretch of the river. The water temperature was 77°F. River clarity was just a few inches.
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MORE RESOURCES

For more information contact watershed@lcra.org

SWIMMING

LCRA's monthly water quality report is intended to give the public a snapshot of overall water quality conditions. But conditions can change quickly. High water quality index ratings do not preclude the existence of bacteria that may cause infections. Swimming in a river, lake or pond, rather than a disinfected swimming pool, carries some risk. So the public needs to take precautions at all times, such as avoiding stagnant water and staying out of the water after rains.

READING THE RATINGS

LCRA monitors the quality of the lower Colorado River as part of its responsibility as the river's steward. The monthly water quality report is issued monthly utilizing data collected by LCRA staff and Colorado River Watch Network certified volunteers to characterize the general quality of the river, tributaries and Highland Lakes using ratings of “excellent,” “good,” “fair” and “poor.” The index is based on a list of parameters, including dissolved oxygen, fecal coliform or E.coli bacteria, nutrients (phosphorus and/or nitrogen), temperature and total dissolved solids or conductivity.

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.

— Updated on May 1, 2012 at 04:08 PM —