Author(s): Melih Calamak; M. Hanif Chaudhry; Lindsey A. Larocque
Linked Author(s): M.Hanif Chaudhry
Keywords: Burrowing animals; Earthen dams; Embankment safety; Internal erosion; Seepage modelling
Abstract: This study investigates the effects of wildlife activities by beavers, muskrats, gophers, and ants on seepage through Barr Lake, Commons Pond, Lake Elizabeth, Village Pond, and Walden Place Dams in South Carolina, USA, using a numerical seepage model. Data was collected from all dam sites for geotechnical testing, and observations were made for animal activities. The laboratory results were used for soil characterization in the finite-element based numerical model. Animal species were determined from the inspection reports and site observations. Two-dimensional steady-state seepage was simulated with a saturated/unsaturated soil model using the Modified Kovacs and Mualem methods. The pore water pressures, hydraulic gradients, seepage velocities, and rates were compared between intact and deteriorated structures. Animal burrows were found to cause increased seepage rates, higher flow velocities, and steeper hydraulic gradients. Four of the five cases indicated the possibility of internal erosion due to animal activity.