Case Study—Colorado 2011-2013 Drought

In May 2011, it became apparent that drought conditions had begun to develop in south central and southeast Colorado and that the agricultural communities in those areas were likely to experience severe impacts as a result. Consequently, the Governor activated the state's drought mitigation and response plan at a phase 2 level for the agricultural sector in that region of the state, which resulted in a number of actions, as highlighted in Table 9.1.

Drought Response Plan Summary

TABLE 9.1

Severity Indicators and Impacts (Colorado Modified Palmer Drought Index [CMPDI] or SWSI, SPI, and US Drought Monitor)

Drought Phase and Response Summary

Actions to be Considered

  • -1 to positive indices in all river basins or modified Palmer climate division
  • -0.5 to positive SPI (6 months)

D0 Abnormally Dry

D0 ranges:

CMPDI or SWSI: -1.0 to -1.9

SPI: -0.5 to -0.7

Indicator blend percentile: 21-30

Impacts: Short-term dryness slowing planting, growth of crops or pastures

Normal

conditions

Regular

monitoring

  • • CWCB/WATF monitors situation on monthly basis, discusses trends with National Weather Service (NWS), State Climatologist, State Engineer, Natural Resource Conservation Service (NRCS), and others as appropriate.
  • • Data reviewed for drought emergence and summarized in Governor's Drought Situation Report.
  • • Implement long-term mitigation actions identified in drought mitigation plan.
  • • ITF chairs meet twice yearly to monitor progress on long-term drought mitigation and review any lessons from previous drought periods, and review the response plan.
  • -1.0 to -2.0 in any river basin or modified Palmer climate division
  • -0.6 to -1.0 SPI (6 months)

D1 Moderate drought

D1 ranges:

CMPDI or SWSI: -2.0 to -2.9

SPI: -0.8 to -1.2

Indicator blend percentile: 11-20

Impacts: Some damage to crops, pastures; streams, reservoirs, or wells low, some water shortages developing or imminent; voluntary water-use restrictions requested

Phase 1

More close monitoring of conditions for persisting or rapidly worsening drought; official drought not yet declared

  • • ITF chairs alerted of potential for activation, monitoring of potential impacts.
  • • Assess need for formal ITF and DTF activation depending on timing, location, or extent of drought conditions, existing water supply, and recommendation of WATF; DTF is comprised of WATF, ITF chairs, and lead agencies.
  • • DTF lead agencies (CDA/ DOLA/DNR) notified of need for potential activation.

Drought Response Plan Summary

TABLE 9.1 (Continued)

Severity Indicators and Impacts (Colorado Modified Palmer Drought Index [CMPDI] or SWSI, SPI, and US Drought Monitor)

Drought Phase and Response Summary

Actions to be Considered

Less than -2.0 in any river basin or modified Palmer climate division

Less than -1.0 SPI (6 months)

D2 Severe Drought

D2 ranges:

CMPDI or SWSI: -3.0 to -3.9

SPI: -1.3 to -1.5

Indicator blend percentile: 6-10

Impacts: Crop or pasture losses likely; water shortages common; water restrictions likely to be imposed

Phase 2

Drought task force and impact task force are activated; potential drought emergency declared

  • • DTF chairs prepare Governor's Memorandum of potential drought emergency based on recommendations from WATF.
  • • Governor's Memorandum activates the drought task force and necessary impact task forces.
  • • Department of Agriculture initiates Secretarial Disaster Designation process if appropriate.
  • • The DTF Chairs and CWCB meet with activated impact task force chairs to outline phase 2 activity.
  • • Activated ITFs make an initial damage or impact assessment (physical and economic).
  • • ITFs recommend opportunities for incident mitigation to minimize or limit potential impacts.
  • • Periodic reports are made by the ITF chairs to the DTF chairs.
  • • ITF chairs designate their respective department public information officer (PIO) to interface with media for their relative area of concern and develop media messages.
  • • Relevant state agencies undertake response and incident mitigation actions with their normal programs with available resources.
  • • The DTF conducts a gap analysis identifying any unmet needs that cannot be handled through normal channels.

Drought Response Plan Summary

TABLE 9.1 (Continued)

Severity Indicators and Impacts (Colorado Modified Palmer Drought Index [CMPDI] or SWSI, SPI, and US Drought Monitor)

Drought Phase and Response Summary

Actions to be Considered

Lowest reading at -2.0 to -3.9 in any river basin or modified Palmer climate division

Less than -1.0 to -1.99 SPI (6 months)

D3 Extreme Drought to D4 Exceptional Drought D3 Ranges

CMPDSI or SWSI: -3.0 to -4.9 SPI: -1.3 to -1.9 Indicator blend Percentile: 3-5

Impacts: Major crop/pasture losses; widespread water shortages or restrictions very likely to be imposed D4 Ranges:

CMPDI or SWSI: -5.0 or less

SPI: -2.0 or less

Indicator blend Percentile: 0-2

Impacts: Exceptional and widespread crop/pasture losses; shortages of water in reservoirs, streams, and wells creating water emergencies

Phase 3

Drought emergency is declared by Proclamation of the Governor

  • • Governor's Memorandum updated to activate additional Impact Task Forces as necessary.
  • • DTF Chairs prepares a Governor's Proclamation of drought emergency.
  • • Governor's Proclamation activates the GDEC.
  • • DTF briefs GDEC.
  • • Activated ITFs continue to assess, report, and recommend response measures and incident mitigation.
  • • Unmet needs are reported to the DTF Chairs.
  • • DTF Chairs determine the unmet needs that can be met by reallocation of existing resources. Those which cannot are forwarded to the GDEC with recommendations.
  • • The GDEC assembles the data provided to advise the Governor with recommendations to support a request for a Presidential Drought Declaration.
  • • Governor requests a Presidential Declaration.
  • • If approved, Federal-State Agreement establishes the Colorado Division of Emergency Management Director as the state coordinating officer (SCO).
  • • Long-term recovery operations commence.

(Continued)

Drought Response Plan Summary

TABLE 9.1 (Continued)

Severity Indicators and Impacts (Colorado Modified Palmer Drought Index [CMPDI] or SWSI, SPI, and US Drought Monitor)

Drought Phase and Response Summary

Actions to be Considered

Lowest reading at -1.6 in any river basin or modified Palmer climate division

-0.8 SPI (6 months)

Return to phase 2

• DTF Chairs and the GDEC determine if all requirements for assistance are being met within the DTF and State agency

D1 Moderate drought Coming out of drought: some lingering water deficits; pastures or crops not fully recovered

Return to phase 1

channels.

  • • GDEC briefs the Governor and prepares Proclamation to end drought emergency.
  • • Long-term recovery operations continue.
  • • ITFs continue assessments.
  • • ITFs issue final report and conclude formal regular meetings.
  • • The DTF issues a final report and is deactivated.

Lowest reading at -1.0 in any river basin

Return to normal conditions

CWCB/WATF resume normal monitoring.

-0.5 SPI (6 months)

Source: Adapted from the Colorado Water Conservation Board, 2013, Colorado Drought Mitigation and Response Plan, Denver, CO, http://cwcbweb]ink.state.co.us/WebLink/0/ doc/173111/Electronic.aspx?searchid=45a1d11c-9ccf-474b-bed4-2bccb2988870.

These actions enabled faster execution of secretarial drought designations, better coordination among local, state, and federal agencies charged with providing assistance, and more timely transfer of data and information. It also made limited emergency agricultural drought grant funds available for the affected area.

Figure 9.1 depicts the evolution of this drought in one hard-hit county of southeastern Colorado (Otero) where precipitation for 2011-2013 was actually less than in any consecutive 3-year period any time during recorded history back to 1890. The suite of SPI values for timescales of 1-24 months is shown (top of figure) alongside a similar depiction of drought for Otero County based on the USDM. Short-duration SPI values began indicating early onset of drought already in the fall of 2010. The drought worsened and spread during the 2011 growing season and then eased a little during the winter before crescendoing to extreme to exceptional drought at all time scales during summer 2012. The USDM lagged the SPI by a few weeks but eventually showed similar severity.

FIGURE 9.1

Standardized Precipitation Index (SPI) for all time scales from 1 month through 24 months, color-scaled to mimic the USDM for the Rocky Ford National Weather Service Cooperative weather station in Otero County, Colorado (a), and coinciding USDM drought classification categories for Otero County, Colorado (b), for the period January 2010 through December 2014. Colors range from white = no drought and yellow = abnormally dry to deep dark red = D4 (Exceptional Drought).

By May 2012, conditions had not only deteriorated but also expanded statewide, and continued to worsen throughout the irrigation season. The conditions at that time are summarized below:

The whole (100 percent) of Colorado was classified as experiencing severe, extreme, or exceptional drought as determined by the USDM. Of that, 69 percent of the state was experiencing extreme drought while 2 percent was classified as in exceptional drought conditions.

1

  • • Modified Palmer Drought Severity indices ranged from -1.01 to -5.3, with most in the -3 to -4 range. This represents severe to extreme drought.
  • • The 6-month SPI across much of the state was -2 (extremely dry), with pockets of -1 (moderately dry).
  • • Much of the west slope of Colorado saw 0 percent of normal precipitation in June; other areas of Colorado saw between 0 and 70 percent of average June precipitation.
  • • The previous 3 months' temperatures had been well above average for most of Colorado, with the month of June running 4 to 8 degrees above average. Statewide, June 2012 was the warmest June on record (1895-2012).
  • • Nearly all major reservoirs in Colorado had seen declines in storage levels in the previous few months.
  • • Irrigation abandonments were being reported.
  • • Sixty-two out of 64 counties had been granted a secretarial disaster declaration for crop disaster, with the remaining two eligible as contiguous counties.

Based on this data and information, the DTF recommended an expansion of activation of the state's drought mitigation and response plan for the agricultural sector to cover the entire state. The DTF also recommended increasing the activation to phase 3 for the agricultural sector only, the highest level of activation possible within the plan. These recommendations were necessary to comply with the state drought mitigation and response plan, support the Division of Emergency Management in their continued justification for secretarial declarations, and respond to serious concerns about drought conditions throughout Colorado. The governor agreed and expanded activation. In June 2013, 2 years after the initial activation of the state's drought mitigation and response plan, the municipal sector was added. This is a great example of the creeping effect that drought can have, slowly expanding into larger regions and multiple sectors. Thankfully in the case of Colorado, unprecedented rains began to fall later that year and into the next, allowing for complete deactivation of the plan. While drought impacts could not be avoided, the overall response of the state was praised as proactive, timely, and responsible.

out of drought. These triggers also provide a basis for greater collaboration among data providers, users, and decision makers by creating a response framework that is data-driven, incremental, and logical.

 
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