Step 4 - Prioritizing
Prioritizing Your List of Projects
Once you have a list of retrofit sites and potential practices at those sites, it’s time to prioritize. And, while a priority list is not necessarily a written-in-stone guide for implementation (see next step), it does help to sharpen the focus of your efforts. For the Eagleville Brook project, we prioritized based on consideration of a long list of both technical and non-technical factors.
Technical factors include pollutant removal capability, impervious area treated, and runoff reduction. You can find ways to estimate the last two in Step 7. Most likely, you will be fine just focusing on impervious cover, since that’s the whole idea. Since you have developed an accurate map of watershed IC in Step 1, you should be able to tally up your list and see how the potential disconnection or removal of IC compares to the target figure put forth in the TMDL (see also our annotated list in Step 5). Non-technical factors include construction cost, maintenance ease and cost, overall feasibility (including property ownership issues), and educational potential.
In the end, the final list will be the result of a subjective process, with the overall idea to produce a list of retrofit projects that reflects “bang for the buck” in terms of reducing the impacts of IC as effectively, and as cost-effectively, as possible. Of course, we predict that your list will sometimes run afoul of contingencies, unforeseen circumstances, blind alleys and…opportunities! Which is why we recommend you take an opportunistic approach.
