Roundtable Discussion Drought History and Impacts to the Big Sky area

Southwestern MT Drought History PDSI 1895-1995 -Measurement of dryness based on precipitation and temperature -Southwestern MT in severe or extreme drought 15-19.9% of the time since 1895 -Significance: only southwestern WY and south central CO are more susceptible to drought conditions in US Source: Bozeman Drought Management Plan pg 9

Upper Missouri Basin: Snowpack History over 600 yrs yearyears “Prolonged and severe drought in the area is chronic” Bozeman Drought Management Plan (p10)

Southwestern Montana Palmer Drought Severity Index: 1900-2010 1970s-Present: focus period of drought impact information in Big Sky Source: NOAA Climate At A Glance

Common Impacts from Drought Reduced snowpack levels Reduced water supplies- increased rates or need to find new sources Reduction in crop yields Low streamflows Poor water quality Fishing restrictions Loss of viable habitat Reduced quality of recreational opportunities Increased erosion Public health risks from dust exposure Increase in wildfire duration, area burned, and intensity Early resort closures Poor soil quality Property damage from wildfires Tourism/recreation job losses Stress on fisheries and wildlife Source: National Drought Mitigation Center: Checklist of Historic, Potential, and Current Drought Impacts

Drought Impacts: Drought Awareness Survey Question 47 respondents from Big Sky community

Teasing out the years Years of moderate to extreme dry conditions -Moderate: Governor's Drought Advisory Committee issues Drought Alert to encourage local committees to convene -Extreme: Local committees implement responses to severe dry conditions, recommendations in MT Drought Plan Source: MT County Drought Status Maps

By the Decades: 70s Southwestern Montana Palmer Drought Severity Index 1970s Gallatin & Madison Counties 1974: Moderate to extreme drought conditions persisted from July-December 1977: Both counties experienced moderate drought in April 1979: Moderate to extreme drought conditions persisted from September-December Source: US Drought Monitor

By the Decades: 80s Southwestern Montana Palmer Drought Severity Index 1980s Gallatin & Madison counties 1980: Moderate to extreme drought persisted through April 1981 (Right half of Gallatin county): Moderate to extreme drought in March & April 1987-1989: moderate to extreme drought throughout SW Montana Source: US Drought Monitor

By the Decades: 90s One of the wettest decades, fewer instances of drought conditions (US Drought Monitor) Gallatin & Madison Counties: 1991: January-March moves from moderate to extreme drought conditions 1992: Right side of Gallatin County reaches moderate drought conditions in March, conditions persist in both counties through May 1994: Moderate drought conditions in September 1999: Moderate drought conditions from November-December Southwestern Montana Palmer Drought Severity Index 1990s

2000-Present Southwestern Montana Palmer Drought Severity Index 2000-Present 2002: Entire state in continuous drought conditions Gallatin & Madison Counties: Frequent periods of moderate to severe drought conditions experienced in: 2003-2008, 2012-2013, and 2015 Source: MT County Drought Status Maps

Drought Impact Reports: 2000-2017