Slide 29 of 36
Notes:
Once sites have been located and determined to be feasible and practical the next step is to set up a plan for future implementation. Even the best stormwater retrofitting programs have limited capital budgets for individual project design and construction. Therefore it is prudent to have an implementation strategy based on a prescribed set of objectives. For example, in some watersheds, implementation may be based on a strategy of reducing pollutant loads to receiving waters where the priority of retrofitting might be to go after the "dirtiest" land uses first. Whereas if the strategy is oriented more towards restoring stream channel morphology, priority retrofits are targeted to capture the largest drainage areas and provide the most storage. Whatever the restoration focus, it is useful to provide a scoring system that can be used to rank each retrofit site based on a uniform criteria. A typical scoring system might include a score for the following items:
- Pollutant removal capability (storage provided and type of practice)
- Stream channel protection capability (ability to control subbankful flow events)
- Cost of facility (design, construction and maintenance costs)
- Ability to implement the project (land ownership, construction access, permits)
- Potential for public benefit (education, location within a priority watershed, visible amenity, supports other pubic involvement initiatives)