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.
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 rainwater 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.
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.
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Section 1: Protection of Natural Resources (Including Trees) and Open Space |
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Section |
Subsection Name |
Points Available |
Points Awarded |
|
1.A.1. |
Sensitive Natural Lands/Critical Area Protection |
17 |
11 |
|
1.A.2a |
Protection of Water Bodies/ Aquifers |
18 |
9 |
|
1.A.2b |
Protection of Water Bodies/Aquifers |
8 |
5 |
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1.B.1 |
Open Space Protection |
9 |
3 |
|
1.C.1 |
Tree Protection |
9 |
9 |
|
1.C.2 |
Tree Protection |
15 |
12 |
|
1.C.3 |
Tree Protection |
6 |
4 |
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Totals |
|
82 |
53 |
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Section 2: Promote Efficient, Compact Development Patterns and Infill |
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Section |
Subsection Name |
Points Available |
Points Awarded |
|
2.A.1 |
Support Infill and Redevelopment |
10 |
5 |
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2.B.1 |
Support Infill and Redevelopment |
23 |
10 |
|
2.C.1 |
Encourage Mixed-Use Developments |
12 |
6 |
|
Totals |
|
45 |
21 |
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Section 3: Design Complete, Smart Streets That Reduce Overall Imperviousness |
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Section |
Subsection Name |
Points Available |
Points Awarded |
|
3.A.1 |
Street Design |
25 |
12 |
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3.A.2 |
Street Design |
9 |
4 |
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3.B.1 |
Green Infrastructure Elements and Street Design |
9 |
3 |
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3.B.2 |
Green Infrastructure Elements and Street Design |
7 |
4 |
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Totals |
|
50 |
23 |
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Section 4: Encourage Efficient Parking |
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Section |
Subsection Name |
Points Available |
Points Awarded |
|
4.A.1 |
Reduced Parking Requirements |
20 |
12 |
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4.B.1 |
Transportation Demand Management Alternatives |
8 |
1 |
|
4.C.1 |
Minimize Stormwater From Parking Lots |
13 |
5 |
|
Totals |
|
41 |
18 |
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Section 5: Adopt Green Infrastructure Stormwater Management Provisions |
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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 |
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5.A.4 |
Green Infrastructure Practices |
5 |
2 |
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5.B.1 |
Green Infrastructure Practices |
10 |
7 |
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Totals |
|
39 |
22 |
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Total Points Awarded |
Score |
Grade |
|
|
257 |
137 |
137/257 * 100 = 53% |
C |
|
A |
80 – 100% |
|
|
B |
60 – 79.9% |
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|
C |
40 – 59.9% |
137 of 257 points = 53% |
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D |
21 – 39.9% |
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F |
0 – 20% |
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The overall grade for this metric is a 53%, which equates to a “C” letter grade which is the same grade as last year. 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 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 1, Protection of Natural Resources (Including Trees) and Open Space, scored the best, receiving 53 of 82 points available or 65%. Section 5, Adopt Green Infrastructure Stormwater Management Provisions, scored the second highest of the categories, receiving 22 of 39 points available or 56%. Section 4, Encourage Efficient Parking, received the lowest score by category, receiving 18 of 41 points available or 44%.
For this fourth 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.
Scoring only the sustainable practices of the Bexar County and City of San Antonio area is a known limitation of the grade for the basin 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 to inspire actions for healthy creeks and rivers in both the urban and rural areas of the San Antonio River Basin.
As with most other watersheds in the United States, development within the San Antonio River Basin has modified the natural function of the basin. In the San Antonio River Basin, infrastructure has been built to direct stormwater runoff into nearby creeks and rivers. This is especially problematic in urban areas during small rain events, where the high concentration of “first flush” pollutants can reduce a waterway’s dissolved oxygen, resulting in fish kills and building concentrations of other containments in the sediment of the waterways bed.
Ensuring the sustainability of creeks and rivers, and the bays and estuaries into which they flow, involves creating projects, incentives, and policy toward reduction of direct runoff and capitalizing on the land’s natural ability to filter pollutants. Green Infrastructure (GI) is a stormwater management strategy that works to replicate the predevelopment hydrologic processes and reduce the harmful impacts of urban runoff. GI techniques have been shown to improve water quality, reduce localized flooding, and when incorporated into a project’s design early in the process, reduce overall long-term costs.
A first step to improving GI use throughout the San Antonio River Basin is for more people to understand this development technique. You can learn more here.
The River Authority, in cooperation with Bexar County, has developed a training program for site planning, design, construction inspection, and maintenance of GI. The training program is comprised of four courses: Site Planning for LID Course, Design of Common LID Practices Course, LID Construction Inspection Course and LID Annual Inspection and Maintenance Course. Those interested in pursuing these courses can learn more here.
Residential homeowners are encouraged to implement GI on their property where feasible. Simple solutions include turning gutter downspouts to vegetated areas instead of draining to impervious surfaces like driveways, installing rain barrels or cisterns, and constructing a rain garden.
You can also join the River Warrior volunteers to actively participate in river stewardship projects as well as attend trainings and educational events to gain knowledge on green infrastructure strategies to become river protection ambassadors.
Finally, community support and demand for the use of green infrastructure is needed to increase the wide-spread use of the development technique. Residents of the San Antonio River Basin are encouraged to use your voice to support green infrastructure. Please follow and tag the River Authority on Facebook, Twitter, and Instagram and use #BeRiverProud to tell us your support for green infrastructure, and be sure to tell your elected officials as well.
Find out more about sustainability and getting involved in helping protect your river, including watershed cleanup projects, building a rain garden, and much more.