The bottom flap must be buried and the posts must be no further than 4' apart. Hay bales must be staked and reinforced with snow fence on the downstream side. When work is proposed in open water areas, a flotation silt curtain must be used. A rock filter dike must be constructed at the entry-ways to all sites. It must be maintained through out construction.
Dikes provide entry for traffic on to the site and control erosion.