Low water

December 21, 2022

This week’s newsletter from the Arkansas Game and Fish Commission included news on removal of one of the low-water crossings in the southwestern part of the state.  Many of the manmade low-water crossings, bridges, and dams can impede the movements of fish to spawning areas, especially smaller fish species.  Thanks to a partnership with Weyerhaeuser, one of these dilapidated low-water crossings was removed to help promote fish movement and improve safety for recreational floaters and anglers in southwest Arkansas.  Removal of the crossing was necessary as the structure presented dangers to those on the water, and because it was in such poor condition it was unsafe for vehicular traffic.  The blockage caused by the structure also caused a major restriction for stream species along that stretch of the river and the feeder creeks to it in the watershed upstream.  Removal was made possible by an EPA-319 grant through the Arkansas Department of Agriculture.

When I looked online, I found the first Federal Water Pollution Control Act (FWPCA) was enacted in 1948 but was completely rewritten as FWPCA Amendments of 1972.  Major changes were later introduced via amendments, including the Clean Water Act of 1977 (CWA) and the Water Quality Act (WQA) of 1987.  The CWA is now the primary federal US law governing water pollution.  Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation’s waters, and was one of the first and most influential modern environmental laws in the nation.  Its laws and regulations are mostly overseen by the Environmental Protection Agency (EPA) in coordination with state governments.  Section 319(h) of the CWA provides funds designated for state and tribal agencies to implement their approved management plans. These were the funds allocated for removal of the low water crossing.

A low water crossing provides a bridge when water flow is low.  Under high-flow conditions, water runs over the roadway and blocks or makes vehicular traffic hazardous.  This approach is cheaper than building a bridge to raise the road above the highest flood stage of a river, particularly in developing countries or in semi-arid areas with rare high-volume rain.  The collapsed low water crossing was removed and the banks on either side of the river were restored.  Native shrubs and trees were planted to reestablish the riparian area and riprap was placed to prevent shoreline erosion along the old roadbed.  The grant is intended to remove all potential fish passage barriers in the Lower Little River watershed, and at least three more barriers will be removed.  The barrier removal opened at least 25 river miles of connected habitat below Dierks Lake to native aquatic species, and more miles can be restored through continued work on the watershed.

THOUGHTS:  Migratory freshwater fish are among the most threatened animals on the planet, declining by 76 percent between 1970 and 2016, a much higher rate of decline than both marine and terrestrial migratory species.  Many of these freshwater species are bait fish for the larger predators we like to catch or eat.  Low-water crossings were quick to build and provided access to rural areas where high water flow was seldom a problem.  Unlike bridges, these structures dam the rivers most of the year.  As these crossings degrade and collapse, they no longer serve for vehicular traffic and remain an impasse for migratory species.  Like many of our past shortcuts, this problem will take time and money to resolve, but if we do nothing the problem will only get worse.  Act for all.  Change is coming and it starts with you.