In North Shore City our small streams are usually very steep near their headwaters. This steepness means that the streams are fast flowing and together with the clay soils that underlie most of the North Shore, this causes severe erosion of the stream bases and banks. 

Residential development on our ridges and the increase in hard surfaces from roofs and driveways further increases stormwater flows and intensifies the erosion problem.

By installing check dams within the stream bed we can slow down the flow rate and reduce erosion. The check dams hold the soil/clay dislodged by the fast flowing water and slow the water down as it cascades through the dam.