The year 2015 saw more than its fair share of extreme hydrologic events, both ruinous floods and severe drought. In the United States, attention remained focused on California, which is suffering the worst four-year drought on record.

For public agencies, the drought has highlighted how unprepared the region is for growing pressures from population growth and from climate change, which has already been implicated in worsening the severity of the drought.

"We have a long way to go," Lassiter says. "But we can make substantial changes. We can even persuade home owners to give up their lawns, which are English imports and not really appropriate to a semi-arid climate like California."