Reduction of Surface Infiltration

Reduction of Surface Infiltration Through Use of Geophysical Methods and Grouting

Geophysical instruments can be used to locate the areas where significant amounts of water are disappearing underground (Figures 1 and 2). Then small holes can be drilled or hammered into the stream less than 1 m into the rock beneath the sediment, and used to inject grout beneath the streambed (Figure 3). The approach has restored 85 - 100% of stream flow, and has even been used to reduce infiltration into active mining operations. The effectiveness of this approach is illustrated in Figure 4.

Figure 1. A two-person version of terrain conductivity being used to locate where stream water is leaving the streambed

Figure 2. Another way of measuring terrain conductivity to identify where water is leaving the streambed, and a graph presenting the results. The peaks
represent areas of high conductivity where the water is infiltrating.

Figure 3. Grout being injected into the stream bed.

Figure 4. The two graphs show how the conductivity peak has virtually disappeared and
how flow has been restored across the formerly damaged streambed.