Report Card Background Image

San Antonio River Basin Report Card

2020

Report Card Summary

2020
San Antonio River Basin Report Card Summary
The overall grade for the 2020 San Antonio River Basin Report Card is B. This grade is the average of twelve individual indicator grades, which are explained in greater detail below.
66.2
Green Infrastructure
Green Infrastructure
How is this being measured?
Explanation of the grade
Key findings

CGreen Infrastructure

While all the metrics in the San Antonio River Basin Report Card have overlapping correlation to the safe, clean, enjoyable creeks and rivers aspects of the River Authority’s mission, the Green Infrastructure for Stormwater Quality grade is primarily related to the clean aspect.

As more natural surfaces are paved and developed, less water percolates into the ground and more water instead flows over impervious surfaces and into storm drains, picking up pollutants and carrying them to creeks and rivers. The untreated rainwater that goes into storm drains and directly to our creeks and rivers is known as stormwater runoff. Stormwater in San Antonio River Basin communities is not treated at wastewater treatment plants. The pollutants picked up by stormwater include, but are not limited to, oil, fertilizers, bacteria, heavy metals, gasoline, and sediment. Stormwater runoff (or non-point source pollution) is the most significant contributor to water quality degradation in the San Antonio River Basin. It is also the most difficult to control, because runoff pollution is potentially caused by every one of the more than 2 million people who live in the basin.

Known Volume of Stormwater Managed

Data from River Authority water quality monitoring indicates that pollutants carried by stormwater runoff are the greatest threat to river basin health. To generate lasting and recognized improvements in river basin health requires the use of green infrastructure practices in land development and management that mimic the natural, pre-development hydrology of the land. The benefits of these sustainable practices include reducing the volume and velocity of stormwater flow that is generated when rainwater hits impervious cover instead of pre-developed lands. Benefits also include filtration of pollutants carried by stormwater flow before the stormwater enters creeks and rivers, and decreasing erosion and its negative effects on both stream banks and community infrastructure such as bridge supports in creek beds. 

In the long run, projects that incorporate sustainable, green infrastructure will decrease the amount of new infrastructure and infrastructure retrofits required to manage floodwater generated by ever-increasing development, conserve and utilize rain water as a valuable resource, add more green space, use native vegetation that provides pollination and habitat benefits, provide air quality benefits, reduce urban heat island effects, and reduce costly pollution and erosion mitigation. Green infrastructure, therefore, helps to balance the environmental, economic, and quality of life benefits for the surrounding area.

How is this being measured?

The Green Infrastructure for Stormwater Quality metric in the San Antonio River Basin Report Card uses the Environmental Protection Agency (EPA) Water Quality Scorecard for Incorporating Green Infrastructure Practices at the Municipal, Neighborhood, and Site Scales. The two main goals of the EPA’s water quality scorecard tool are to: “(1) help communities protect water quality by identifying ways to reduce the amount of stormwater flows in a community and (2) educate stakeholders on the wide range of policies and regulations that have water quality implications.”

The EPA’s water quality scorecard tool includes a point system to make it easier to evaluate and improve local programs. The scorecard allocates “points available” across a variety of areas within five primary sections addressing Protection of Natural Resources (Including Trees) and Open Space; Promotion of Efficient, Compact Development Patterns and Infill; Design of Complete, Smart Streets that Reduce Overall Imperviousness; Encouraging Efficient Parking; and Adoption of Green Infrastructure Stormwater Management Provisions.

For the past decade, the River Authority has been a leader in advocating for and/or implementing green infrastructure stormwater management projects including natural channel design, green infrastructure and Low Impact Development (LID) projects and development code amendments. The River Authority has provided training on LID since 2012, growing its portfolio to include three LID credential courses in partnership with Bexar County and a number of LID presentations offered on request, including presentations on LID basics; LID design, construction, and maintenance errors to avoid; and the chemistry underlying LID stormwater management. Incorporating significant stakeholder involvement, the River Authority funded and managed creation of the San Antonio River Basin LID Technical Design Guidance Manual, first released in 2013 and updated in 2019 to include an additional LID feature requested by the development and design community.  

Known Volume of Stormwater Managed

In addition, the River Authority has advocated for incentives to encourage greater adoption of these alternative development and land management approaches. Two results are the City of San Antonio’s approval of incentives for LID and natural channel design during the 2015 Unified Development Code amendment cycle (see Article II, Section 35-210) and the River Authority’s Watershed Wise School Grant and Rebate Program launched in 2014. Click here to view completed projects and the volume of stormwater and pollutants being managed by those projects throughout the San Antonio River Basin.  

For the City of San Antonio’s 2015 Unified Development Code (UDC) amendment cycle, the River Authority funded the stakeholder-driven project resulting in the February 2016 approval of a LID ordinance establishing the City’s LID fee and credit-offset incentives and the stormwater management standards required to receive them. In an effort to protect the public investment in the Museum Reach and the Mission Reach sections of the San Antonio River Walk, the River Authority also submitted an amendment to the River Improvement Overlay (RIO) District section of the UDC to mandate LID on developments abutting the San Antonio River in RIO’s 1-2 and 4-6. An update in 2017 incorporated San Pedro Creek into the RIO, thus providing protections to the then-future San Pedro Creek Culture Park improvements project.

The River Authority also has invested staff time and expertise to the City of San Antonio’s SA Tomorrow Comprehensive Planning process to advocate for open space, floodplain, and other sensitive natural feature protections; LID and green infrastructure; shared parking paradigms, green complete streets, and other innovative policies designed to decrease impervious cover while meeting human needs; multi-benefit projects; and, ultimately, protection of rivers, creeks, and streams. The River Authority has also participated in the City of San Antonio’s Climate Action and Adaptation Plan process, for which a River Authority director has recently been named an Organizational Member of the Technical & Community Advisory Committee. Through this work, the River Authority will guide the community in better understanding that green infrastructure is a development solution that addresses not only stormwater quality and quantity, but also climate, air quality, equity, and other issues of significance under the SA Climate Ready program.  

For this year’s basin report card grade, we are using the EPA’s water quality scorecard and awarding points per category. The points are largely being awarded based on the Bexar County/City of San Antonio area of the San Antonio River Basin by using data captured from the above projects as well as from regional GIS data and known code, policy, planning, and programming of other San Antonio River Basin governmental entities. The final grade for this metric will be determined by dividing the total points awarded by the total points available and then multiply by 100.

Explanation of the grade

 

Section 1: Protection of Natural Resources (Including Trees) and Open Space

Section

Subsection Name

Points Available

Points Awarded

1

Sensitive Natural Lands/Critical Area Protection

17

9

1.A.2a

Protection of Water Bodies/ Aquifers

18

9

1.A.2b

Protection of Water Bodies/Aquifers

8

5

1.B.1

Open Space Protection

9

3

1.C.1

Tree Protection

9

8

1.C.2

Tree Protection

15

12

1.C.3

Tree Protection

6

0

Totals

 

82

46

 

Section 2: Promote Efficient, Compact Development Patterns and Infill

Section

Subsection Name

Points Available

Points Awarded

2.A.1

Support Infill and Redevelopment

10

4

2.B.1

Support Infill and Redevelopment

23

10

2.C.1

Encourage Mixed-Use Developments

12

6

Totals

 

45

20

 

Section 3: Design Complete, Smart Streets That Reduce Overall Imperviousness

Section

Subsection Name

Points Available

Points Awarded

3.A.1

Street Design

25

11

3.A.2

Street Design

9

3

3.B.1

Green Infrastructure Elements and Street Design

9

3

3.B.2

Green Infrastructure Elements and Street Design

7

4

Totals

 

50

21

 

Section 4: Encourage Efficient Parking

Section

Subsection Name

Points Available

Points Awarded

4.A.1

Reduced Parking Requirements

20

10

4.B.1

Transportation Demand Management Alternatives

8

2

4.C.1

Minimize Stormwater From Parking Lots

13

6

Totals

 

41

18

 

Section 5: Adopt Green Infrastructure Stormwater Management Provisions

Section

Subsection Name

Points Available

Points Awarded

5.A.1

Green Infrastructure Practices

13

10

5.A.2

Green Infrastructure Practices

6

1

5.A.3

Green Infrastructure Practices

5

2

5.A.4

Green Infrastructure Practices

5

2

5.B.1

Green Infrastructure Practices

10

7

Totals

 

39

22

 

Total Points Available

Total Points Awarded

Score

Grade

257

127

127/257 * 100 = 49.4

C

Key findings

The overall grade for this metric is a 49.4%, which equates to a “C” letter grade. It should be noted, however, that no municipality in the United States will be able to receive every point available in the EPA water quality scorecard because the scorecard is intended for use by a range of community types and sizes in locations throughout the U.S. That said, a “C” grade for this metric indicates that some successful work has been done in the Bexar County/City of San Antonio area related to green infrastructure, but more can, and should, be done to help protect and improve water quality in the San Antonio River Basin.

Of the five categories in the EPA’s water quality scorecard, Section 5 (Adopt Green Infrastructure Stormwater Management Provisions) scored the best with Section 1 (Protection of Natural Resources [Including Trees] and Open Space) coming in as a very close second. There’s a significant drop in points between the top two Sections and the other three. Section 2 (Promote Efficient, Compact Development Patterns and Infill) and Section 4 (Encourage Efficient Parking) are also closely scored, but about 12 points further away than the top two Sections. Section 3 (Design Complete, Smart Streets That Reduce Overall Imperviousness) came in with the least points, by percentage of available points per section. 

For this inaugural San Antonio River Basin Report Card, this green infrastructure metric has generated a grade related to work being done in Bexar County and the City of San Antonio area. This area is in the upper section of the San Antonio River Basin and is the largest urban population within the basin. Pollution entering the creeks and rivers in the Bexar County/City of San Antonio area has the potential to cause concerns throughout the basin; therefore, implementing green infrastructure practices in the upper reaches of the basin can also provide benefits further downriver. A “C” grade, being average, does show some promising results. To raise this grade in the coming years, more can be done in terms of encouraging, incentivizing, and/or mandating green infrastructure and confirming proper maintenance of green infrastructure features to ensure the stormwater reaching area creeks and rivers has been treated for water quality and slowed down to reduce erosion and contribution to flood flows. 

It should also be noted that only scoring the sustainable practices of the Bexar County and City of San Antonio area is a known limitation of the grade for this year’s report card. The rural land use practices of the southern basin may also impact the health of the river basin. Therefore, it is the River Authority’s intent to expand the use of the EPA’s water quality scorecard, where feasible, to include grading sustainability work being done in Wilson, Karnes, and Goliad counties as well. By expanding the use of the EPA’s water quality scorecard into the more rural areas of the San Antonio River Basin, we believe the grade for this green infrastructure metric, in time, will more accurately reflect the reality of the entire basin and can be used as inspire actions for healthy creeks and rivers in both the urban and rural areas of the San Antonio River Basin.

Report Card CTA Background

SHOW YOUR RIVER PRIDE

MAKE A DIFFERENCE

Find out more about sustainability and getting involved in helping protect your river, including watershed cleanup projects, building a rain garden, and much more.