Raising the top of the wet well, valve vault and generator pad to an elevation of 549 feet helped the Rochester Primary Pump Station mitigate damage caused by previous extreme weather events. |
The purpose of the Hazard Mitigation Grant Program (HMGP) is to help communities implement hazard mitigation measures following a Presidential Disaster Declaration. The HMGP is administered by the Federal Emergency Management Association (FEMA), with administration assistance from the state EMA (in this case, the Illinois Emergency Management Association [IEMA]). HMGP is a unique source of funding that can be creatively applied to public infrastructure that is vulnerable to extreme weather events such as flooding. Projects must provide a long-term solution to a recurring disaster problem. FEMA HMGP grants may fund up to 75 percent of the eligible costs of each project. The grantee must provide a 25 percent match.
Rochester’s eligibility to apply for HMGP funds hinged on two factors. First, the completion of Sangamon County’s Hazard Mitigation Plan, which was approved by FEMA in 2008 (plan is effective for five years and must be current). Second, a Presidential Disaster Declaration, which occurred in 2010 after severe storms and flooding occurred in Illinois.
Once HMGP funding was possible, the Village asked consulting engineering firm Crawford, Murphy & Tilly (CMT) to evaluate the pump station and make recommendations for improvements so services would not be interrupted during major flooding events in the future. An inquiry was made and IEMA allowed CMT and the Village to submit a project description in late 2011, then offered solution alternatives in early 2012.
FEMA agreed that the mitigation solution needed to protect the pump station to an elevation of 549 feet. Three solution alternatives were presented to FEMA, the Village and other stakeholders:
- A highway barrier wall outside of the fence.
- A retaining wall with security fence and flood gate.
- Raising the top of the wet well, valve vault and generator pad to an elevation of 549 feet. (This solution was selected.)
The first two alternatives (the highway barrier and the retaining wall) required active intervention in the case of flooding, whereas the chosen solution did not require action from Public Works staff. The “passive” nature of this alternative was one of the main reasons FEMA recommended it and the Village chose to raise the structures as its mitigation solution.
CMT’s final design of the mitigation work at the primary pump station included raising the wet well, valve vault, and standby generator pad using cast-in-place and pre-cast concrete. All the original electrical controls were located on top of the wet well.