Springfield has already spent $20 million to purchase land to be used for Hunter Lake's bed. The total cost of the project, as of 2016, is loosely estimated at $106 million. Hunter Lake concerns, raised by the Army Corps of Engineers in September 2011, included: (a) the age, in years, of the information contained in the original environmental impact study (EIS) submitted by CWLP, (b) changes and additions to EIS law that have taken place since the original EIS was submitted, (c) inadequate consideration of the adaptive re-use of existing Sangamon County gravel pits as a potential water storage capacity alternative, and (d) inadequate consideration of the drilling of groundwater wells into a Central Illinois aquifer or aquifers as a potential alternative supplemental water supply. Additional concerns raised as of 2016 include: (e) inadequate consideration of improving the water capacity of existing Lake Springfield by dredging the lake, (f) potential for the fluctuating Hunter Lake to become a place for mosquitoes to breed, (g) the impact of Hunter Lake on the neighboring municipalities of Divernon, Pawnee, and Virden, (h) stagnant water-consumption growth patterns in Springfield that call into question the cost-benefit assumptions made by the original planning documents, and (i) algae blooms in the proposed lake's shallow water. The village of Pawnee, in public comments, has expressed concerns about the Hunter Lake reservoir proposal.