Components of a sustainable watershed

Below are several key components of a sustainable watershed. These components are not mutually exclusive – they all work together to create healthy watershed.

Good water quality Water with good water quality has very low levels of pollutants and contaminants. It is safe for recreation such as swimming and kayaking and is 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, stormwater polishing techniques are utilized throughout the watershed that actually reduce the amount of taxpayer funded infrastructure that is needed. There will still be some need for public infrastructure. However, infrastructure is built in an economical, environmentally-friendly and less obtrusive way.

Threats to watersheds

Below is a listing of some common threats to sustainable watersheds. These threats usually harm rivers by increasing contaminants in water bodies and/or increasing the volume, velocity and natural temperature of stormwater.

Luckily, there are solutions available to protect our watershed from the threats mentioned below. Click here to learn more.

Threat: Harms: Examples: Why?
Non-point source pollution

water quality

aquatic habitat

Automotive fluids washing into streams off of roads.

Pet waste washing into streams from yards.

Non point source pollution is pollution that enters waterways from many, many different small sources.

This type of pollution harms waterbodies by increasing levels of bacteria, nutrients and hazerdous chemicals.

Impervious ground cover

water quality

aquatic habitat

riparian habitat

Asphalt, concrete and roofs

Hard surfaces do not allow stormwater to absorb into soil. This increases the volumn 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 unatural levels. An example of this is the duck populations 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 elevated bacteria levels in water bodies and erosion.

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 of the concrete channels and into water bodies.

These channels also raise water temperature unaturally 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 allows contaminants by mimicking natural stream processes using vegetation. This method also coveys floodwater more efficiently while minimizing erostion to streams. An added benefit is that they can also be much more visually appealing.