Serene area of the San Antonio River while padding along the SASPAMCO Paddling Trail

Low Impact Development Sustainability

An Introduction to Watershed Sustainability

Think for a moment about the word sustainability. What comes to mind? For many people, environmental sustainability means recycling, conserving energy and water, or reducing air pollution. All of these things are essential in creating a healthy environment that can be sustained for generations to come. However, maintaining clean and healthy water in our creeks and rivers is also an essential element of environmental sustainability.

How the San Antonio River Authority Defines Sustainability

The San Antonio River Authority (River Authority) is dedicated to achieving a sustainable watershed through improving water quality in the San Antonio River Basin. We believe that sustainability is achieved by implementing solutions that balance a set of criteria that is often referred to as “the triple bottom line.” To meet these criteria, sustainability solutions must:

  • Be good for the environment    
  • Be good for people
  • Make sound financial sense.
Triple Bottom Line Venn Diagram

How we care for our watershed now will determine the health of rivers and streams for future generations to enjoy. Polluted San Antonio River water harms more than just the fish and wildlife in our local area. Water that drains into the San Antonio River flows all the way to San Antonio Bay where it has direct impact on the health of wildlife in the bay and the Gulf of Mexico.

However, a sustainable watershed is not just good for the environment. In the long run, it will save taxpayer money through reduced infrastructure costs. It will also improve quality of life in our watershed through increased green space, walkability, and landscape beautification.

If we do not take steps now to encourage a healthy watershed, we could be susceptible to federal government intervention in the future. We feel that it is important for the community, not the federal government, to be responsible for decisions made about the river. Below are several key components of a sustainable watershed. These components are not mutually exclusive – they all work together to create a healthy watershed.

Good water quality

Creeks and rivers with good water quality have very low levels of pollutants and contaminants. They are safe for recreation such as swimming and kayaking and are a healthy home for wildlife.

Healthy riparian habitats

A healthy riparian habitat contains native vegetation that acts as a buffer that filters out pollutants before they enter creeks or streams. Healthy riparian habitats are also able to support a diverse array of native animal species.

Healthy aquatic habitats

A healthy aquatic habitat provides a safe home for aquatic animals that live in our watershed. A healthy aquatic habitat is free of pollution and contains a variety of areas for animals live.

Sustainable stormwater infrastructure

In a sustainable watershed, LID, green infrastructure, stormwater parks, innovative parking paradigms, and other technologies and policy actually reduce the amount of taxpayer funded infrastructure that is needed.

Threats to a Watershed

Below is a listing of some common threats to sustainable watersheds. These threats usually harm rivers by increasing pollutants and/or increasing the volume, velocity and natural temperature of stormwater runoff that flows to the rivers.

Luckily, there are solutions available to protect our watershed from the threats mentioned below. On-site stormwater management such as low impact development, green infrastructure including stormwater parks, and stream restoration are a few best management practices that the San Antonio River Authority implements and advocates for a more sustainable watershed.

Threat:

Harms:

Examples:

Why?

Nonpoint source pollution

  • Water quality
  • Aquatic habitat
  • Automotive fluids washing into streams off of roads
  • Pet waste washing into streams from yards

Nonpoint source pollution is pollution that enters waterways from many different sources. This type of pollution harms water bodies by increasing levels of bacteria, nutrients and hazardous chemicals.

Impervious ground cover

  • Water quality
  • Aquatic habitat
  • Riparian habitat
  • Asphalt
  • Concrete
  • Roofs

Hard surfaces do not allow stormwater to absorb into soil. This increases the volume and velocity of stormwater entering waterways, which leads to erosion. Water quality is also harmed because there is no vegetation present to filter out pollutants.

Unnatural animal populations

  • Water quality
  • Aquatic habitat
  • Riparian habitat
  • Large duck populations on the River Walk
  • Feral hog populations

When people feed wildlife rather than allowing animals to be fed by natural food sources in their habitat, populations can grow to unnatural levels. An example of this is the duck population on the River Walk in San Antonio. Another way animal populations can grow out of control is if the animal species is a non-native species that has no natural predators. An example of this is feral hogs that are seen throughout the San Antonio River Basin. Overpopulation of wildlife is bad for the watershed because it tends to result in erosion and elevated bacteria levels in water bodies.

Concrete Drainage Channels

  • Water quality
  • Riparian habitat
  • There are numerous examples throughout the basin

Concrete drainage channels are designed to quickly move water off of streets and property, and they do this job well. However, they also result in erosion to creeks and rivers as water rushes out the concrete and into water bodies. These channels also raise water temperature unnaturally and do not assist in helping filter out contaminants from stormwater coming off of streets and roads. Luckily, there is a method of channel design called “natural channel design” that filters contaminants by mimicking natural stream processes using vegetation. This method also conveys floodwater more efficiently while minimizing erosion to streams. An added benefit is that they can also be much more visually appealing.