Green Infrastructure Dashboard
Since 2014, the San Antonio River Authority (River Authority) has provided incentives such as rebates for the creation of green infrastructure features. The River Authority has also created an interactive green infrastructure dashboard (above) that provides information about the amount of stormwater and select pollutants that the features manage.
Stormwater runoff is the greatest threat to river health in the San Antonio River watershed with many other US communities reporting the same problem. Unlike pollution from an industrial pipe, which can be traced to its source, stormwater runoff can originate from anywhere within our watershed such as parking lots, rooftops, unsecured construction sites, roadways, and even our own yards. In urban areas, runoff is designed to be carried from these surfaces to the storm drain system and then directly to a nearby river, creek, or stream.
In our watershed, stormwater runoff is not cleaned at a treatment plant before being discharged into the environment. Pollutants like oil, grease, metals, bacteria, sediment, fertilizers, pesticides, pet waste, and thermal pollution accumulate on the surfaces. During rains, runoff carries the pollutants to our creeks and rivers and during hard downpours, runoff can contribute to street and neighborhood flooding. Stormwater runoff prevents creeks and rivers from primary and secondary contact recreation during and for approximately 72 hours after rain events. Over time, surges of runoff from urbanized areas erode creek banks and can negatively affect bridge and other community infrastructure.
Green infrastructure is a design and land development approach that alleviates these negative runoff impacts. Bioretention systems, stormwater cisterns, permeable pavement, buffers, retention of native infiltrative soils, green space preservation, natural channel (river) design, and several other sustainable development approaches perform natural or nature-mimicking functions that slow, capture, and/or clean stormwater runoff—like nature intended. The design and installation of green infrastructure meets our goals of reducing local flooding and improving water quality by mimicking natural areas to slow, detain, and filter stormwater.
Unlike a storm drain and concrete-lined river segment, which are designed for the singular purpose of water passage, green infrastructure provides multiple benefits.
Along with reducing neighborhood flooding and pollution in our creeks and rivers, green infrastructure benefits include:
- reducing the heat island effect
- improving human health
- creating or preserving valuable wildlife habitat, including for monarchs, bees, and other pollinators essential to our human food supply
Learn more in this module about the benefits of green infrastructure and what you can do to help protect our creeks and rivers.
Treated Stormwater is water runoff that is detained and/or filtered by green infrastructure to remove pollutants including sediment and bacteria. Treated Stormwater volume is measured in cubic feet (1cubic foot = 7.5 gallons).
Bioretention are depressed areas that slow stormwater which reduces local flooding. These areas also filter stormwater removing some pollutants including sediment and bacteria. Filtered stormwater makes streams and rivers healthy for plants and animals.
|Bioswales are vegetated drainage paths which soak up and filter stormwater runoff from roofs or pavement. Bioswales are constructed with quick-draining soil and drainage layers to filter stormwater and provide water for plants.|
|Cisterns are storage containers that detain stormwater which reduces local flooding. Cisterns also allow the captured stormwater to be slowly released to porous planted areas where plants and soils are able to filter out the pollutants and clean the water before it reaches the river.|
|Permeable Pavement provides a load bearing porous surface over a storage layer. Permeable pavement reduces volume and delays stormwater runoff which reduce local flooding. Permeable pavement also removes sediment and bacteria making river water clear and healthy for plants and animals|
Sediment are fine particles suspended in stormwater. Sediment from stormwater makes streams and rivers appear cloudy which affects the health of all river plants and animals. Other pollutants such as nutrients, metals and bacteria attach to sediment and are deposited at the bottom where they can harm plants and animals.
|Bacteria measures fecal coliform bacteria which is measured in number of colonies. Fecal coliform is used as an indicator of contamination with other pathogens which cause disease in humans. When bacterial levels are high, human contact can result in sickness. Reducing bacteria makes the river safe for contact activities.|
|Green Roof A vegetated landscape built up from a series of layers that are installed on a roof surface as ‘loose-laid’ or modular (that is, installed layer by layer on the roof or as pre-prepared layers in trays).|