Examples of Triggers in Action
According to President Dwight Eisenhower, "Plans are useless, but planning is everything." He went on to explain that the definition of an emergency is that it is unexpected, so it will not occur the way you plan it. This is certainly true of drought; but comprehensive, proactive, and integrated drought planning and preparedness can help states and communities to be better equipped to respond when a drought event does occur. As has been shown in Colorado, the combination of active monitoring, proactive mitigation, a qualitative and quantitative vulnerability assessment, and a well-thought- out staged response framework can lessen the overall negative impacts of an event. Furthermore, comprehensive drought planning can inform overall water planning efforts, helping to ensure a more secure water future for regions prone to water scarcity (Finnessey 2016).
Colorado's Drought Mitigation and Response Plan
The State of Colorado has incorporated quantitative trigger points that guide the activation of the staged drought response plan. These trigger points were developed by analyzing observed climate data and overlaying that information with past impacts. This provided quantitative thresholds at which certain impacts are likely to start occurring. The existence of these predetermined decision points has helped to depoliticize the activation process and speed aid to those most impacted by drought. Without the use of longterm observed climate records, it would not have been possible to accurately develop these thresholds.
While the plan has had general triggers for action since its initial development, they were refined after the 2002 drought, which was the driest year on record in Colorado, and then refined again in 2008. In 2012, the state faced another severe statewide drought in what turned out to be the second- driest year on record, but by using the triggers, the state began responding to the drought before the impacts became as severe as in 2002. As a result of this and other changes made after the 2002 drought, the overall drought response in Colorado was more coordinated in 2012 than in 2002 (Ryan and Doesken 2013), with entities such as municipal water providers implementing response measures sooner than previously implemented, and tourism and recreation outfitters diversifying activities to offset revenue losses.
The State of Colorado officially uses a number of indices to guide statewide decision making, including the US Drought Monitor (USDM), the Colorado Modified Palmer Drought Index (CMPDI), the surface water supply index (SWSI), and the SPI. All but one of these indices are described in detail in Chapter 8 in this book, the exception being the CMPDI. The CMPDI is a complex soil moisture calculation, similar to the Palmer drought severity index in that it requires weekly or monthly precipitation and temperature data as inputs. However, the PDSI was initially developed for areas of the country with more precipitation and more homogeneous climates, so Colorado adapted the index by separating the state into 25 climatically similar regions. In recent years, the Colorado Climate Center has added a 26th region—the Sangre de Cristo Mountains, which previously did not have adequate data. The Colorado Modified Palmer Index uses a +4 to -4 scale. It uses a 0 as normal, and drought is shown in terms of negative numbers; for example, -2 is moderate drought, -3 is severe drought, and -4 is extreme drought (Colorado Water Conservation Board 2013).