Flooding

Much of the region is located in a flat flood plain with slowly permeable soils, and has a great history of flooding. These natural features combined with rapid development have significant negative impacts on the residents in the region. The impermeable nature of buildings and paved surfaces reduce the land’s ability to absorb storm water. Additionally, past efforts to protect residents from floods have focused mainly on concrete lined, strait channels, without much regard for the natural flora and fauna.

Consequences of Flooding

Flooding can both help and harm ecosystems. Estuaries benefit from increased nutrients and sediment brought by floods, but the excess water and its velocity can disrupt freshwater ecosystem processes, kill plants and animals, and have devastating consequences on residents.

These facts became particularly apparent in June of 2001 when Tropical Storm Allison flooded thousands of homes and businesses and left 22 people dead.

Flooding has serious economic impacts on the region as well. About 25 percent of Harris County's population lives within the 100-year floodplain; the region also has the highest number of repeat flood damage claims of any metropolitan area in the country. Damage from Tropical Storm Allison is estimated at $5 billion.  

Flood Management

Concreting channels, a traditional method of flood control, has sometimes proven to be an effective way of removing water quickly, but also has flaws. This method destroys habitat and is only a temporary fix. Some environmental groups, such as the Bayou Preservation Association, advocate other flood control measures, such as detention, diversion, and flood plain buyouts. They say system storage should be the first priority in watershed management; system conveyance should be the second priority. Development policies that reduce impervious surfaces and subsequent runoff are vital as well.

Some are advocating major changes to flood management policy as well. System watershed capacity, or the total amount of water the watershed can non-destructively accommodate, should be considered a publicly owned resource, they argue, and no development project should be allowed to reduce or diminish it.

Recent Progress

Public Awareness

The aftermath of Tropical Storm Allison brought the flooding issue – and the opinions of environmentalists – to the forefront.

Remapping the Floodplain

The Federal Emergency Management Agency (FEMA) has begun work with The Harris County Flood Control District to redelineate the region’s floodplains. Using updated hydrology and rainfall data, FEMA will be producing new Flood Insurance Rate Maps in three years. For more information, visit the project website at www.TSARP.com

This section was taken from the State of the Environment 2002, the introduction to the 2002 Environmental Resource Guide, produced by the Citizens' Environmental Coalition (CEC). The above statements do not necessarily reflect the opinions of CEC, its trustees, officers, or staff.