Preview the paper we presented at the 2017 Dam Safety Conference
Rodents and burrowing animals can create voids in structures, endangering public safety. Sachin Mandavkar, Maccaferri’s Technical Manager, presented a paper at the 2017 Dam Safety Conference in San Antonio, Texas outlining how to reduce their impact.
The presence of rodents and burrowing animals such as beavers, ground squirrels, and prairie dogs on levees is a historic and ongoing problem that poses a threat to levees roadways and structures endangering public safety.
Recent studies show an increase in the population of beavers and other rodents in North America and Central Europe over the last 15 years. The animal burrows can grow to 30 feet in length and may extend two to four feet below ground causing voids resulting in levee stability issues. In many instances, this leads to serious stability concerns and levee failures along rivers in the floodplain areas.
A post Katrina study by the University of California, Berkeley, cited rodent burrows as a “pervasive problem” with earthen levees in New Orleans. The California Department of Water Resources 2005 white paper “Flood Warnings: Responding to California’s Flood Crisis” lists animal burrows as one key factor in levee degradation statewide. The U.S. Army Corps of Engineers routinely requires its local partners nationwide to perform burrow control on federally built and funded levees.
“Beavers pose concern in streams and channel improvement projects”
– The U.S. Army Corps of Engineers
They have been known to cause problems by building dams, blocking culverts, and by burrowing into the stream bank to create a den. When beaver activity is identified, the beaver should be removed and the dam and blockages repaired. Failure to correct the problem may result in increased bank erosion and slope stability problems in the area of the beaver den during periods of high water.
Damage reduction methods for rodents generally involve lethal approaches to reduce the densities.
Most of these mammals, however, are protected species and more humane methods of intervention are preferred. Universities, research institutes and environmental agencies have been monitoring measures to permanently safeguard the banks using our MacMat R composite erosion control systems with polymer coated steel wire mesh (as flexible reinforcement component) and geosynthetic (to promote vegetation growth) without harming the animals and their habitats. The steel mesh component works as an effective long-term barrier against the intrusion of mammals, discouraging them from digging inside the levee core.
Research analyzed by Paolo Di Pietro, Technical Director, Officine Maccaferri S.P.A., Italy, presents several additional benefits of utilizing a composite made of steel mesh and extruded geomat along levees, such as:
- Strong and durable erosion protection
- Accelerated vegetation growth
- Ability to conform to irregular shapes along the levee slope
- Ease of installation, maintenance
- Surface protection against ice impacts in northern regions
Missed the Dam Safety Conference? Read about our findings and solutions in the exclusive full paper, available here prior registration to our reserved area.