City Gives Discounts for Watershed Protection | Fluence

Green roofs, such as these in Sydney, Australia, are one strategy for keeping rainwater from overwhelming municipal infrastructure.

Texas capital joins other areas of Southwest in dealing with alternating droughts and flooding

In Texas, which experiences alternating droughts and deluges, water management issues have always been vitally important.

The City of Austin Watershed Protection Department, influenced by a susceptibility to flash flooding and a time-honored tradition of stormwater storage in cisterns, is now offering drainage charge discounts to users of green stormwater infrastructure (GSI) features, which can include green roofs, rain gardens, ponds and rainwater harvesting systems.

Keeping Water Where It Falls

The Watershed Protection Department calculates its drainage charges by determining how much impervious cover is present on a property. This includes roofs, driveways, walkways, patios, and outbuildings. Impervious cover sheds water rather than letting it soak into the soil, so much of it ends up in the municipal drainage system.

Conversely, GSI interrupts stormwater’s progress toward the municipal drainage system by collecting and storing it for later use or by slowing its progress toward the gutter, allowing it to soak into the soil or fill water features. GSI can include:

  • Green roofs, covered with plants and soil that sequester water.
  • Ponds or rain gardens between a house and the street, which refill when it rains, keeping water from the drainage system.
  • Cistern systems that can use water for later irrigation or even for flushing toilets.

All of these GSI features complement Watershed Protection’s efforts to reduce drainage impact and pollution from runoff. The discount allows applicants to offset drainage charges for up to half of the impervious cover on a property, encouraging adoption of new GSI projects as well as recognizing the existing efforts of some Austinites to mitigate the often-severe flooding in the area.

Stormwater Projects in Other Cities

Low-impact municipal stormwater strategies can be roughly characterized as attempts to soak up water before it can turn into a flood, whether they’re at the homeowner level, as in Austin, or at neighborhood, district, or city levels.

Texas is not alone. The experience is the same across much of the American West, where most municipal stormwater strategies are used to mitigate damage done in the relatively short periods when too much water is a problem, but do little to take advantage of rain during the rest of the year, when it’s in short supply.

According to Tony Davis of the Arizona Daily Star, the City of Tucson, Arizona, is beginning to remove some stubborn regulatory impediments to “curb cuts” that allow stormwater to run from the streets into green spaces.

More impressively, however, flood-plagued Tucscon, in partnership with a local nonprofit, is rolling out grants to neighborhood associations for up to $45,000 to create neighborhood-scale stormwater harvesting infrastructure.

In Seattle, the city Housing Authority’s High Point Redevelopment, a 120-acre, low-cost housing development, created an entire neighborhood from the ground up with innovative stormwater features, including rain gardens, swales, and a central lagoon.

And, Seattle Public Utilities recently joined forces with private developers, to create a nearly 700-acre project called Thornton Creek Water Quality Channel, which they hope will be a catalyst for future development in the district.

Water Recycling

Technology is now available to treat stormwater and even sewage to any desired level of purity. In the past, treatment for reuse was done at large facilities on a citywide level. Now, there’s interest in using medium-scale, decentralized wastewater treatment plants to treat water at the point of use.

Today’s better water reuse technology gives cities that deal with alternating problems of flooding and water shortage yet another effective water management tool.