Graph of the Day: Water Levels of Anvil Lake in North Central Wisconsin, 1936-2010

Between 2000 and 2010, the worst drought ever recorded since Euro-American settlement hit the Colorado River Basin. Water levels in Lake Mead dropped to record lows. The drought not only threatened the supply of water to cities like Las Vegas, it also harmed the ecosystems and riparian areas that support countless fish, plants, and animals and endangered species, like the humpback chub and the southwestern willow flycatcher. Climate models project that the decade-long drought that gripped the region may become the normal climate instead of the rare exception, perhaps as soon as the end of the 21st century (Barnett and Pierce 2009, Rajagopalan, et al., 2009). The threat is being taken seriously by the Bureau of Reclamation, which has developed a plan that brings all stakeholders together in an attempt to balance human needs for water while providing sufficient flows and habitat for sustainable fish, wildlife, and plant populations. Similar challenges must be faced around the nation. Long-term records at Anvil Lake, a groundwater-fed lake in northern Wisconsin, highlight the importance of water levels to fish, wildlife, and plant species. Over centuries, the lake’s water level has risen and fallen. However, Anvil Lake’s water level became progressively lower during each succeeding dry period, especially during the most recent dry period (WICCI 2011). In the future, any water loss through evapotranspiration associated with warmer temperatures would be expected to exacerbate any drought effect in similar aquatic systems. These examples hold an important lesson for adaptation strategies. To help plants, wildlife, and ecosystems adapt to a changing climate, it is not enough to focus just on the natural world. Ensuring that ecosystems have enough water in regions expected to experience more droughts will require working with farmers, municipalities, energy industries, among others, to reduce the overall demand for the increasingly scarce water.

National Fish, Wildlife and Plants Climate Adaptation Strategy draft