,#tDsr%

'&?) N8NP0IHT SOURCE SUCCESS STORY

Implementing Best Management Practices and Low Impact
Development Improves Water Quality in the Upper San Antonio River

Waterbody Improved T^e Upper San Antonio River assessment unit (All) 1911_07 was

first identified as impaired due to elevated bacteria in the 1996
Texas Integrated Report of Surface Water Quality Inventory and Clean Water Act (CWA) section
303(d) List (Integrated Report). Since then, efforts to improve water quality by state and federal
agencies and local outreach have been focused on implementing best management practices
(BMPs), education and outreach, and construction of low impact development (LID). These
combined efforts have led to water quality improvements in the Upper San Antonio River. As a
result, AU 1911_07 was identified as fully supporting recreational use water quality standards in
the 2020 Integrated Report.

Problem

The San Antonio River in South Central Texas flows
240 miles through Bexar, Wilson, Karnes, Goliad, and
Refugio counties, converging with the Guadalupe River
before flowing into San Antonio Bay on the Gulf of
Mexico. The Upper San Antonio River (segment 1911)
is located in the southern portion of the Salado Creek-
San Antonio River watershed (Figure 1). AU 1911_07
has a designated primary contact recreation 1 use
and an Escherichia coli (E. coli) criterion of 126 colony
forming units (cfu)/per 100 milliliters (126 per 100 mL).

The geometric mean concentration of E. coli samples
from the Upper San Antonio River (AU 1911_07) was
not meeting the criterion of 126 per 100 mL and was
first added to the state's CWA section 303(d) list of
impaired waters in 1996.

in 2007, a total maximum daily load (TMDL) for
bacteria in segment 1911 was adopted by the Texas
Commission on Environmental Quality (TCEQ) and
approved by the U.S. Environmental Protection Agency
(EPA). The TMDL Identified nonpoint sources, includ-
ing urban stormwater, failing septic tanks, livestock,
and wildlife, as contributing to the impairment. A
TMDL implementation plan (l-Plan) for segment 1911
followed and was approved by TCEQ in 2016. Thirty
management measures to reduce bacteria are speci-
fied in the TMDL l-Plan.

Terns

This map was generated by the Water Quality Planning Division of the Texas Commission on Environmental Quality. This product is tor informational purposes anc
nay not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey and represents only
he approximate relative location of property boundaries. For more information concerning this map, contact the NPS Team at 512-239-6682.

Figure 1. The Upper San Antonio River watershed is in
southern Texas.


-------
Story Highlights

E. coli Data for AU 1911 07

200

2010	2012	2014	2016	2018	2020

Integrated Report Year

Geometric Mean	Criteria (126 cfu/100 mL)

Figure 2. Upper San Antonio River (AU 1911_07) E. coli
geometric means from the 2010-2020 Integrated Reports.

In 2006, the San Antonio River Authority (SARA)
completed the Upper San Antonio River Watershed
Protection Plan (WPP). An update to the WPP was
approved by EPA in 2015. From 2008 to 2010, CWA
section 319(h) funds were used for the San Antonio
River Walk implementation project. This project
funded 23 educational workshops, installed 10 signs
to educate the public about why they should not feed
wildlife, and used power washers to clean San Antonio
River Walk sidewalks and recapture the waste.

CWA 319(h) funds were also used to implement
several LID projects in the watershed. In 2011-2015,
a project at the Mission Library installed LID features,
including permeable pavement, a bioswale, a bioreten-
tion area, and a rain garden with rainwater harvesting
system. The Mission Library project also funded six
workshops and five site tours of the installed LID
features. Another LID project using CWA 319(h) funds
to implement the Upper San Antonio River WPP was
conducted in 2015-2018 at two sites located at SARA's
corporate campuses. A permeable parking lot, nine
bioretention cells, and seven water-capturing cisterns
were installed. Monitoring analysis of these sites esti-
mated the combined potential to remove 46 percent
of the annual bacterial load from stormwater runoff.
The bioretention cells also served as an outdoor
classroom that SARA used to educate the public about
native plant species, LID and BMP features, and reduc-
tion of potable water use. SARA has hosted more than
13 site tours and two workshops at this location.

Other nonpoint source pollution management mea-
sures include avian management for the San Antonio
River Walk and riparian areas, expansion of the Pooper
Scooper Program, and feral hog management. Since
2016, the City of San Antonio has used a falconer and
a laser device to reduce the grackle population in
the downtown area and installed over 173 pet waste
dispensers in 75 public parks via the Pooper Scooper
Program. Texas A&M AgriLife Extension has hosted
three feral hog workshops. A new outreach campaign
emphasizing "Don't Feed the Wildlife" was launched
in fall 2019 for all areas of the San Antonio River Walk,
Museum Reach, and Mission Reach.

Along with activities conducted by TCEQ, the Texas
State Soil Water and Conservation Board (TSSWCB)
has funded programs responsible for 12 workshops

with over 700 attendees from 2015 to 2020. Programs
offered included Texas Well Owner Network, Texas
Watershed Stewards, feral hog education, and Texas
Stream and Riparian workshops partnering with
Texas Water Resources Institute, Texas A&M Agri Life
Extension, and Texas A&M Agri Life Research.

Results

During the 2008-2020 period, targeted implementa-
tion activities in the watershed have helped to reduce
nonpoint source pollution. TMDL l-Plan's management
measures that focus on point sources, such as mainte-
nance programs to reduce sanitary sewer overflows,
have also helped to reduce bacteria. SARA has contin-
ued to promote LID projects; since 2016, 96 LID proj-
ects have been received, and 41 have been approved.
New data collected in 2011-2018, after management
measures were put in place, were assessed in the 2020
Integrated Report, and the geometric mean of E. coli
samples was 118.56 cfu/per 100 mL (Figure 2). As a
result, AU 1911_07 was identified as fully supporting
the recreational use water quality standards in the
2020 Integrated Report.

Partners and Funding

Watershed partners have spent approximately
$2,078,791 on education and outreach efforts and
implementing BMPs, combining $1,247,275 in federal
CWA 319(h) funds with $831,516 in matched funds
by local entities. Watershed partners include the City
of San Antonio, SARA, San Antonio Water System,
Texas Water Resources Institute, Texas A&M Agri Life
Extension, and Texas A&M Agri Life Research.

^edsj^ U.S. Environmental Protection Agency

0** Office of Water
^ Washington, DC

WJ

EPA 841-F-22-001U
pro^° November 2022

For additional information contact:

Brian Koch, TSSWCB

979-532-9496 • bkoch@tsswcb.texas.gov
Samantha Litchke, TCEQ

512-239-5635 • samantha.litchke@tceq.texas.gov


-------