(a) Subject to section 17(c) of the act (32 P. S. § 680.17(c)), the Department may establish a system of prioritizing designated watersheds for preparation of watershed stormwater plans which shall consider, but not be limited to, the following factors:

1. (1) County endorsement of need, including expressed willingness to undertake stormwater planning.
2. (2) Existing and potential stormwater and flood damage problems associated with current and future development.
3. (3) Number of stormwater management complaints.