NONPOINT SOIRCf SICCESS STOIY
Implementing Stormwater Practices Improves Concho River Aquatic Habitat
Waterbody Improved
Nutrient and sediment loads from upstream urban sources degraded
habitat in a portion of Texas' Concho River. As a result, the Texas
Commission on Environmental Quality (TCEQ) placed a 5-mile portion of the Concho River (assessment
unit [AU] 1421 _ 07) on the state's 2002 Clean Water Act (CWA) section 303(d) list of impaired waters for
failing to meet Texas' water quality standards for macrobenthic communities. TCEQ, Texas State Soil and
Water Conservation Board (TSSWCB), Upper Colorado River Authority (UCRA) and the city of San Angelo
implemented several best management practices (BMPs) and programs in San Angelo that reduced
nutrient and sediment loading into the North Concho River, which is upstream of the impaired segment.
Aquatic habitat improved in AU 1421 _ 07, and TCEQ removed it from the CWA section 303(d) list in 2012.
Problem
The main stem Concho River begins at the conflu-
ence of the North Concho and South Concho rivers
in the city of San Angelo. The North Concho River is
affected by urban runoff from the city of San Angelo
(Figure 1). Sedimentation and nutrient enrichment
problems associated with urban runoff, along with
low flow, have had a detrimental effect on the aquatic
life in the Concho River.
A 2002 biological assessment of AU 1421 _ 07, which
is directly downstream of the confluence, showed
that the AU's Benthic Index of Biotic Integrity (BIBI)
score fell below the minimum score of 29 that would
indicate support of aquatic life. As a result, TCEQ
included AU 1421 _ 07 on the 2002 CWA section
303(d) list for macrobenthic community impairment.
Macrobenthic organisms are sensitive to changes
in water quality and nonpoint source (NPS) pollut-
ants, making them an indicator species of the overall
health of a waterbody. Sediment, dissolved solids,
nutrients and diminished flow can negatively affect
macrobenthic communities in freshwater streams.
Sediment loading into the North Concho River
degrades macrobenthic habitats downstream and
disrupts the organisms' ability to filter feed.
Project Highlights
Many parties collaborated to implement BMPs in
the Concho River watershed. A CWA section 319(h)-
funded program was initiated in 1994 between San
Angelo, UCRA and TCEQ to restore the North Concho
River by constructing BMPs that reduced sediment
and nutrient loads from Stormwater runoff. A gabion
retention structure designed to reduce Stormwater
Concho River BMPs
Bank Stabilization
(R) Detention Pond
Education & Outreach
Gabion Structure
Hydraulic Dredging
(IS) Aqua Swirl
Figure 1. Map of BMP Locations in San Angelo, Texas.
runoff was constructed at the Civic League Park in
San Angelo in 1998. This was the first of many struc-
tural BMPs built using CWA section 319(h) funding to
reduce urban runoff and pollutant loading to the North
Concho River. The construction of two additional
BMPs, a wet retention pond at Brentwood Park and
a dry detention pond at Santa Rita Park, were com-
pleted in 2001. A gravity-based Stormwater cleaning
device was installed in downtown San Angelo in 2007.
After Stormwater is gravity-separated and filtered in
this device, high-quality effluent from the system is
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Figure 2. Partners added
bank-stabilizing BMPs along
the North Concho River.
discharged into the river or
pumped into nearby "living
laboratory" demonstration
ponds, which are part of the
expanded public education
effort. More recent BMPs
have included the hydraulic
dredging of the North Concho
River, completed in 2010,
followed by stabilizing select
sections of the bank in 2011
(Figure 2). These improve-
ments removed silt and
sediment from the river and stabilized areas of bank
deterioration, thereby mitigating slumping and erosion
that contribute to streambed deposition of sediment.
Finally, management actions have facilitated addi-
tional water quality improvements in the Concho
River. These actions have included the Concho River
Watermaster Program, established in 2005, and
development of the 2008 Concho River Watershed
Protection Plan (WPP). The Concho River Watermaster
Program provides two local Watermaster deputies
with the authority to resolve water rights issues in the
area. The deputies are responsible for monitoring and
regulating water availability, as well as establishing
measures that control the flow of the river and allow-
ing diversions when necessary. This program devel-
oped rules requiring base flows entering an upstream
reservoir to be released downstream, resulting in
increased flows in AU 1421 _ 07.
The 2008 Concho River WPP was developed by the
UCRA, with funding from TSSWCB. The WPP evalu-
ated and assessed potential sources of NPS pollution
and identified control strategies. Components of
the plan included a public stakeholder outreach and
education program, water quality monitoring, the
development of water quality goals and objectives,
and implementing BMPs to improve water qual-
ity. The Concho River Basin Aquatic Research and
Education Center, built in 2008, supports the water-
shed improvement effort by providing a permanent,
publicly accessible venue for educational workshops
about NPS BMPs and water quality issues.
Results
Approximately 3,273 tons of sediment and debris have
been removed from stormwater through the gravity-
based stormwater cleaning BMP and bank stabiliza-
tion projects implemented in downtown San Angelo.
BenthiclBI
40
35
30
25
20
15
10
5
0
BenthiclBlinAU1421_07
_^ —
.R2 = 0.7781
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*_>— * — """""""'"
Standard
JJ VQ OO -t- C3
Wofe: Monitoring station changed in 2008.
1 1
§ §
Figure 3. The BIBI scores in the Concho River AU 1421 _ 07
improved from 1996 to 2009.
The gabion structure at Civic League Park removed
36,000 pounds of sediment and organic matter in its
first year. Through monitoring, the Brentwood reten-
tion pond has been found to remove 99 percent of
incoming total suspended solids, 85 percent of the
biochemical oxygen demand (BOD5), and 98 percent
of fecal coliform from stormwater entering the river.
The dredging of the river removed roughly 1.43 million
cubic feet of silt and added over 10 million gallons
of storage capacity. Water quality data indicate
that concentrations of sediment and phosphorus
have decreased in the North Concho River directly
upstream of the delisted AU. During a 2008-2009
assessment AU 1421 _ 07 received a mean BIBI of
32.6, resulting in the waterbody being removed from
the CWA section 303(d) list in 2012 (Figure 3).
Partners and Funding
Watershed partners have spent approximately
$3,928,263 on water quality improvements in the
North Concho River, combining $2,358,958 in CWA
section 319(h) funds with $1,569,305 matched by
local efforts. Of these combined funds, TCEQ grant-
ed $1,983,718 with $1,322,478 from local match, for a
total of $3,306,196. The TSSWCB provided $375,240
with $246,827 from local match, totaling $622,067.
Private funding for NPS water quality improvements
on the North Concho River in San Angelo included
a contribution of $260,000 from a private benefac-
tor, Ms. Mayme Daniels, in 1997. The city of San
Angelo also implemented a 1/2-cent sales tax to raise
$11 million for NPS BMPs.
E1
111
o
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-001XX
November 2015
For additional information contact:
Jessica Uramkin, Texas Commission on Environmental Quality
512-239-6685 • jessica.uramkin@tceq.texas.gov
Brian Koch, Texas State Soil and Water Conservation Board
979-532-9496 • bkoch@tsswcb.texas.gov
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