By 2005, the lake surrounding Carter Lake had reached a crisis level. Due to a number of factors, the lake water level was both dangerously low and polluted with toxic algae. This situation prompted concerned citizens both in Carter Lake and surrounding communities to form a not-for-profit group in an effort to improve the quality of the lake. They have held many meetings, proposed studies, held annual lake cleanups, encouraged city, county and state government participation (both in Iowa and Nebraska), received grants, and generally greatly improved both awareness of the problem and the quality of the lake in general.
See the Carter Lake Preservation Society website for more details.