Effects of Flooding At Trinity River National Wildlife Refuge
LIBERTY, June 16, 2015 – From the highly photogenic cattle drive on US 90 to the hopelessly trapped cars off the interstate, the recent flooding in Houston has garnered the media’s attention nationwide. Without a doubt, the flooding has proven to collect tremendous tolls on everyday life across the city. But beyond the city limits and suburban neighborhoods, the flooding poses an entirely different set of issues, particularly within the confides of the Trinity River National Wildlife Refuge in Liberty County, TX.
The refuge encompasses 29,000 acres of bottomland hardwood forest, 95% of which is currently submerged in water. Prior to the flooding, only 5% of the refuge resided underwater. Standing water is inherently troublesome, allowing for contamination of drinking water sources and the culmination of waterborne pathogens. Run-off often times causes substantial environmental damage, such as the contamination from submerged oil field areas.
The refuge has been almost completely submerged for around 90 days and has, since then, undergone noticeable short term changes. In search of dry land, wildlife has dispersed onto higher ground – often placing themselves in greater danger alongside public roads. Snakes have taken to higher ground, camping in unsubmerged tree branches. Bird colonies on the river have dispersed, seeking less submerged trees to build nests. Fire ants have coped with the rising water levels by clustering into living rafts, floating on the surface of these infantile fake lakes.
Although animals have improvised unorthodox methods of transportation, a wide majority of the refuge is now inaccessible to wheeled vehicles owned by the U.S. Fish and Wildlife Service. Likewise, interns volunteering for the refuge have improvised by navigating the territory using kayaks and canoes. The flooding has altered the topography of the river, making it tremendously easier to get lost or disoriented by the current and lack of landmarks.
Navigating the refuge under these conditions proves to be utterly exhausting, especially when the desired field locations are either submerged or inaccessible within the flood zone. Large pastures once traversed by truck become large lakes filled with choppy waves under windy conditions. Field sites once close and easily accessible now can only be accessed by miles of boat rides. Because of this, many conservation and maintenance projects have been postponed. Usual work duties are slowed, if not halted altogether. Plans to build a boardwalk on the Knobby Knees Trail were compromised. This lack of certainty has lead to highly variable schedules for the U.S. Fish and Wildlife Service employees and volunteers.
Despite this variability, the management of invasive plants is of utmost importance within the flood zone. Highly persistent plants, such as Chinese tallow and Japanese mimosa, have an easier time propagating with the help of the current. Preexisting clusters of terrestrial invasive plants have drowned beneath the flooding, no longer within sight and capable of being sprayed with herbicide, while others such as aquatic invasives plants, such water hyacinth and giant salvinia, have opportunistically floated from the lake in which they were confined to other functioning wetlands, ready to invade and proliferate.
Nevertheless, these clouds have a silver lining. Episodes of regular flooding are naturally occurring events necessary for general health of bottomland hardwood forests. The flooding provides a natural source of population control, culling overgrown endemic plants and animals. Since the five-year drought has ended, soil fertility and general moisture level have greatly improved. The increased soil quality combined with the culling of plant overgrowth provides a forest-scouring service to the refuge, allowing for new growth once the water finally recedes.
The flooding comes as a postponed spring cleaning, a frantic process in practice with noticeable results in the ending. As the water level finally recedes, we interns hope to continue our submerged projects while observing the immediate effects of the flood.
If you would like to visit the Trinity River National Wildlife Refuge, please contact refuge staff at 936-336-9786 prior to your visit. Champion Lake Public Use Area and all hiking trails are closed due to flooding until further notice.
By Meg Deeter, Wildlife and Habitat Conservation Intern