How to un-wreck our wetlands
Yes, Houston floods. But here’s what we can do to combat that
For the past 20 years, we at Bayou Land Conservancy have watched, horrified, as the Houston region’s wetlands are scraped and filled in — directly resulting in increased flooding.
When wetlands are allowed to function, they’re the kidneys of the area’s watershed. Their special soil types are surrounded by particular wetland plants that help hold water in shallow depressions. They clean the water as they allow some of it to filter slowly into the ground, the rest to drain slowly into our bayous. That process is the foundation of our region’s ecology.
The rampant destruction of our forested and prairie wetlands is upsetting this balance, drastically reducing the land’s ability to absorb water. By allowing so many wetlands to be turned into subdivisions, we’re not just kicking them to the curb; we’re turning them into curbs. We need the ecological equivalent of dialysis.
Yes, conservationists have scored large victories. Bayou Land Conservancy, based in the Cypress Creek watershed, has preserved more wetlands in perpetuity than any other regional conservation group in Texas, and with the Spring Creek Greenway, we’ve helped to form the longest urban greenway in the U.S., one that protects many acres of wetlands within its floodways.
We shudder to think how much worse the massive flooding in northern Harris and southern Montgomery counties would have been without the 13,000 acre, 30mile greenspace “sponge” buffer to their properties. But as that flooding shows, our efforts, and the ef- forts of other conservation groups in our area, haven’t been enough.
We simply cannot keep pace with Houston’s ever-increasing development. Too often, that development doesn’t work with nature, but instead cuts forests, plows under prairies and fills in with concrete our ever-more-rare absorptive wetland soils.
As many of us again pull up soaked carpets, some for the third time in less than 10 years, we should stop using the wishful verbiage of “500-year floods” and “100-year floods” — we’ve seen too many of both in our lifetimes — and start reality-based talk and action.
Yes, Houston floods, and with more construction permits issued daily, it will increasingly do so. But there are actions we can take:
• Trees and native plants — both those directly on bayou banks, and those anywhere in the watershed — absorb floodwater. According to American Forests, in one day one large tree can lift up to 100 gallons of water out of the ground and discharge it into the air. For every 5 percent of tree cover added to a community, stormwater runoff is reduced by 2 percent. In the 1960s, Houston was home to the Moon Shot. It is time for a Tree Shot.
• Lobby for enforcement of existing laws. The Galveston Corps of Engineers has never had enough funding to adequately monitor the myriad “after-the-fact” permit situations that arise, much less to oversee strict enforcement of those projects that were permitted.
• Cities and counties whose citizens are affected by these permits (which is to say: everyone) should have more power in this permitting process than just being able to weigh in during the public-comment period.
• Bayous are like freeways: You can’t keep increasing their speed and capacity forever. There’s a limit to how much water even an optimized-for-speed concreted bayou can move toward Galveston Bay, and we’re reaching it. Instead, we need to think about slowing down the water, detaining it in ways that don’t harm our houses and displace wildlife, horses and people.
• Political action is important — but there are lots of things we can do ourselves, directly. In our yards, we take out quick-to-runoff St. Augustine grass and plant diverse native vegetation (preferable deep-rooted prairie grasses and pollinator flowers). At the grocery store, we can stop using the plastic bags that later fly out of trash cans and clog storm sewers. And we can stop buying water in the single-use plastic bottles that clog our drainage systems.
• We all need to become more aware of our area’s natural systems. For starters, know your watershed. In the Houston area, for the most part, it’s the bayou or reservoir that rain falling on your roof eventually drains into.
• We need to educate our kids and ourselves about our area watersheds. In “No Child Left Inside” field trips, Bayou Land Conservancy teaches thousands of students and teachers what their immediate watershed is, how water flows from one watershed to another, and what they can do to lessen humans’ impact on them. In different parts of our area, Katy Prairie Conservancy, Greens Bayou Coalition, Houston Audubon and Galveston Bay Foundation do similar conservation and education.
• Cease and desist the construction of trapezoidal concrete detention areas. Engineers like right angles; nature doesn’t. These retention/detention “ponds” are, plain and simple, mosquito pits. In a natural pond, dragonflies live up to three years in their nymph stage, during which their favorite food is mosquito larvae. But dragonflies require natural slopes and vegetation to crawl out of the water. With vertical concrete boundaries, we are creating Zika-virus-ready non-natural concrete holes in the ground.
Let’s each do our part to make our watersheds healthier and decrease flooding. We need to protect our remaining precious and irreplaceable wetlands. Dialysis works only for so long.
Jennifer Lorenz will end her 16-year career with Bayou Land Conservancy as executive director on April 30. She will be honored in May by the North Houston Association for her years of environmental advocacy efforts. This column originally appeared on Gray Matters at houstonchronicle.