ENVIRONMENT FRIENDLY SOLUTIONS TO EROSION CONTROL IN ALBERTA

Erosion of soils due to rain and wind forces is a natural phenomenon. Man's activities can either reduce the natural erosion process or, as often is the case, further compound it. This is especially true in the case of construction activities, like highway construction which entails stripping of the topsoil, removal of the existing vegetation, slope modification or other disturbance of the natural landscape. Alberta Transportation and Utilities has a policy to restore areas affected by highway construction and maintenance to their natural state by revegetating the land within the right-of-way. This consists mainly of hydroseeding and harrowing of over 19,000 acres of land annually. On occasion, when hydroseeding alone can not solve the erosion problem and in environmentally sensitive areas, more elaborate erosion control methods and materials are used. This paper summarizes the results of two erosion control experiments involving the use of soil-bioengineering methods and new erosion control blankets for improved erosion and sediment control. From these experiments we found that the construction of the soil- bioengineered systems were very labour intensive and resulted in very high project expenditures. There were also differences in the performance and the cost of the various live systems which should be considered prior to implementation. The most successful methods from our experience were joint planting and live soft gabions. The erosion control blankets used for instant erosion control of roadside ditches were able to reduce ditch erosion and prevented sediment from entering a fish- bearing creek. Their selective use in environmentally sensitive areas are encouraged. (A) For the covering abstract of the conference see IRRD Abstract no. 807788.