| Abstrakt: |
Stormwater low-impact development (LID) has become an important method for the reduction of stormwater runoff emanating from impervious surfaces to local water bodies. The extra runoff from human-made impervious surfaces overloads water bodies with polluted runoff. Since many LID best management practices (BMPs) exist, and many areas have multiple subcatchments, it is important to carefully select which BMPs to place in each subcatchment and its placement in order to minimize cost, but also to give the highest chance of owner BMP maintenance. LID BMPs are often constructed on private land and maintenance can be at the owner's expense and, therefore, not guaranteed. A new algorithm, entitled multi-objective, socio-economic, boundary-emanating, nearest distance (MOSEBEND), that is easily used by practitioners is introduced and demonstrated here for a road in a community showing that the algorithm allows the selection of the set of BMPs on the various subcatchments with the lowest cost, highest runoff restoration to natural values, and highest likelihood of private-owner maintenance. The BMP selection and location starts at the downstream watershed boundary and propagates upstream, and then works in the upstream-to-downstream direction from the upstream watershed boundary. The multiple objectives addressed are cost-benefit ratio (CBR) and maintenance probability factor (MPF). The optimal solution is considered to be the one closest to the origin on a plot of CBR and MPF. It was found that the new algorithm resulted in a solution that is (1) low cost, (2) high benefit, and (3) more likely to be built and maintained than an analysis of any subset of these three objectives. The option with the highest cost-benefit-ratio is that in which LID BMPs are implemented in the upper and steeper portion of the catchment, for the watershed that the algorithm is demonstrated herein. However, that option has a less likely chance to be maintained and, therefore, is not ranked first by the MOSEBEND algorithm proposed here. [ABSTRACT FROM AUTHOR] |
