Dense planting of live stakes in King County Washington. Planting like this can provide rapid establishment of vegetation at low per unit costs compared to alternatives such as planting nursery reared seedlings. Low initial costs also allow for low subsequent maintenance costs, since reduced survival can be compensated for in advance by planting large numbers of these inexpensive propagules. Photo: Stream Corridor Restoration: Principles, Processes, and Practices, 10/98, by the Federal Interagency Stream Restoration Working Group (FISRWG)
Basic soil bioengineering techniques can be a very cost effective means of stabilizing slopes, preventing soil erosion, and maintaining the quality of riparian habitats. More than anything else, what determines cost effectiveness is the appropriate selection of erosion control method for the specific circumstances being considered.
The graph at right was produced by the Great Lakes Sustainability Fund, a program administered by Environment Canada. Using average costs taken from existing projects, it approximates the cost per meter of erosion control resulting from basic soil bioengineering and compares it on up through a series of increasingly intensive hard engineering structures.
Depending upon the circumstances- such as where protection of lives, infrastructure, and property is at issue, expensive stone, concrete, or steel may very well be warranted. However, in many cases simpler, less expensive solutions are not only sufficient in terms of safety and getting the job done, but are superior due to softer impacts and greater environmental benefits.
This means that where its use is appropriate, soil bioengineering may not only be less expensive, but can be more effective than equivalent "hard" engineering solutions. Factors influencing the costs of these techniques include:
the cost of inputs
the accessibility of the site
the need for follow up maintenance
Approximate Costs for Erosion Control (per metre) Averages based on existing projects, calculated by Great Lakes Sustainability Fund