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For over two years straight, at least one third of the U.S. and Puerto Rico has been in drought. In that same time, the extent of drought across the contiguous 48 states hasn’t dropped below 40%. Yet, the U.S. does not have a comprehensive national drought plan, and under our federal system of government, much authority resides with states. Some of those states opt to plan for droughts with the intention of reducing vulnerability and increasing the resilience of communities, industries and ecosystems.

To date, though, there has been little empirical research on the comprehensiveness and quality of state plans that address drought. To fill that gap, researchers from the National Drought Mitigation Center and the Technical University of Munich have evaluated plans from 49 states to understand whether those plans include effective preparedness and mitigation measures, as well as what drives certain states to plan for drought. Their work was recently published in the journal Water Resources Management.

Common sense suggests that states are more likely to take on the expense and effort of creating drought plans because of the risk that drought poses. Indeed, the new analysis confirms this notion that drought risk is an intrinsic driver of planning.

“In the end, the results showed that the occurrence of drought is connected with planning comprehensiveness,” said Theresa Jedd, an environmental policy specialist at the Technical University of Munich and the study’s lead author (and a former postdoc at the NDMC). “Even though that might seem intuitive, it was somewhat surprising because it’s rare to establish a clear, singular policy driver.”

But, before Jedd and her co-author, Kelly Helm Smith, assistant director of the NDMC, could test the relationship between drought exposure and planning comprehensiveness, they needed to come up with a way to measure comprehensiveness. Using the American Planning Association’s drought guidelines, expert consultation and the academic literature on drought planning, Smith and Jedd identified several key measures by which to evaluate each plan. Those criteria included, among others, having a clear definition of drought and a strategy for monitoring it; incorporating actions to both respond to drought and mitigate its impacts; and addressing related issues like water quality and quantity in drought planning.

With their new evaluation framework in place, they turned to the NDMC’s database of state-level drought plans. At the time, it had 171 individual current plans, published between 2000 and 2021. Since 2019, the database has incorporated a variety of different plan types that contain provisions for responding to or mitigating drought in addition to ‘stand-alone’ drought-centric plans. “It’s encouraging to see that drought planning isn’t an isolated activity anymore,” Smith said. “The idea that everyone should consider drought in their plans is really taking hold.”

The researchers, for example, also evaluated water, multi-hazard mitigation and climate plans that include drought, in addition to drought-specific documents. Each plan was given a score based on the team’s evaluation criteria. Each state was then given a total score combining the different plan types. Scores for climate plans were excluded, however, due to their variable formats and given that not every state had one.

“The database allows researchers to look at broad patterns in state planning and ask questions that would have previously been impossible,” said Jedd about the value that the NDMC’s database has for researchers like her.

With individual and state-level scores in place, Jedd and Smith could then statistically compare the relationship between a state’s planning score, income tax revenue and drought exposure, based on the U.S. Drought Monitor Drought Severity and Coverage Index. Both drought exposure and plan scores varied dramatically, but, as the researchers expected, the two were related. Those states in the top third in terms of drought exposure, like the Southwestern states, had a higher median planning score than states with lower drought exposure.

The researchers also thought that, perhaps, it’s a state’s financial resources that encourage drought planning. But surprisingly, the other relationship they looked at to test that idea—between income tax revenue and drought exposure—didn’t pan out.

“We expected that a state’s financial resources would play a role in how comprehensive a state’s drought planning was simply because these plans can be expensive and require significant collaboration and expertise,” said Jedd. “So, it was somewhat surprising to see that, on the aggregate level, tax revenues don’t impact plan scores.”

There were some outliers, of course, to the trend. Indiana and Rhode Island, for example, were in the bottom third in terms of drought exposure; yet both had some of the highest total planning scores of any state. The researchers expect that both states’ long history of drought planning—Rhode Island, for example, had its drought of record back in the 1960s—has helped them be more proactive and prepared. For Jedd, those outliers highlight another value of having a comprehensive database of drought plans. She says they can be a useful resource for planners who are looking to learn from each other and adopt best practices from other states.

“Establishing a connection between experiencing drought and planning for drought is a step forward in our scientific understanding of drought planning,” Smith said. “Sometimes it takes years or multiple episodes for a state’s drought experience to turn into a drought plan.”  

Meanwhile, the NDMC’s constantly growing collection of plans that address drought may be of use to those just embarking on planning or who want to see how other states are tackling the challenge. The NDMC provides the database as a service to drought planners around the country. Anyone involved in state drought planning and response is welcome to provide updates to the NDMC by emailing ndmc@unl.edu or ksmith2@unl.edu.

-- Leah Campbell, NDMC Communications