New building standards can help reduce runoff from downpours North Texas has seen recently and these measures are getting attention with extreme weather expected to increase in years to come.
There’s talk in Dallas of making voluntary measures a requirement in the future.
In one downpour Sunday, water raced off the paved parking lot, but the water that fell in a landscaped area was held back. That’s the idea behind some of the floodwater mitigation measures.
At the Oak Cliff Nature Center, a place that soaks up a lot of rainwater, environmental activist David Marquis said slowing runoff is good.
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“Because when you get a lot of water at once it hits those storm systems. It backs them up. You get floods in the streets, floods in the neighborhood,” he said.
The Encina Restaurant on Davis Street in Oak Cliff is an example of a different development standard. There is very little concrete in the parking lot. Instead, there is gravel in the parking lot and landscaping that allow water to soak into the ground and slow water that leaves the site.
A concrete parking lot on Lemmon Avenue near Inwood is surrounded by a bioswale. It’s a retention area that keeps rainwater from heading to storm drains.
In Deep Ellum, rain gardens have replaced sections of the sidewalk area along streets that used to be covered with concrete. Now, these places hold back water that would have raced into the storm drain.
“Economic development is a good thing. A dynamic economy is a good thing. But we need to be smart about it and do it in such a way that we are capable of planning for the future,” Marquis said.
The City of Dallas 11 years ago approved a set of regulations for a new development called Integrated Storm Water Management or iSWM. It recommended these measures but only made them voluntary.
Dallas City Council Member Paula Blackmon, chair of the Dallas City Council Environment Committee said Monday that a switch to mandatory iSWM rules is being discussed at City Hall as part of an overhaul in all green building rules.
“One of the things we have to do is begin to look at some of these things on a regional level. These are regional issues. If water falls over there, it ends up here,” Marquis said.
The Trinity River through Dallas receives flood water from fast-growing communities upstream that may not follow storm water retention policies.
Marquis said the regional approach is necessary because science says current extremes will become more normal.
“As bigger droughts and harder rains fall, we need to deal with them now on the front end. And we need to do it not just for ourselves. We need to do it for our grandchildren and future generations because if we don’t they’re the ones that are really going to suffer,” he said.
Marquis said some communities have pursued ‘net-zero runoff’ which would use various measures to keep all rain that falls on a property from leaving that property.
