WEATHER MODIFICATION An Upper Basin Perspective On Winter Cloud Seeding

BACKGROUND Colorado River Basin Growth and Water Demand Population Increase Population Increase Current Level of Development Current Level of Development Drought Drought Uncertain Hydrology Uncertain Hydrology

Basin States Growth Projections Population in 1000s Population in 1000s state state Arizona Arizona California34,44149,285 California34,44149,285 Nevada Nevada Total41,74158,009 Total41,74158,009 39% increase – 16 million people 39% increase – 16 million people

Basin States Growth Projection state state Colorado Colorado New Mexico New Mexico Utah Utah Wyoming Wyoming total952011,989 total952011,989 26% increase – 2 1/2 Million people 26% increase – 2 1/2 Million people

Lower Basin Uses Arizona, California and Nevada using nearly 100% of their apportionment Arizona, California and Nevada using nearly 100% of their apportionment Lake Mead Inflow (normal) 9.1MAF Lake Mead Inflow (normal) 9.1MAF Lake Mead Outflow+ Evap 10MAF Lake Mead Outflow+ Evap 10MAF Declining Lake Mead Storage Declining Lake Mead Storage Current Uses May Exceed Inflow Current Uses May Exceed Inflow

THE DROUGHT 5 years of extreme drought ( ) 5 years of extreme drought ( ) Unregulated inflows 62,59,25,51,49 % Unregulated inflows 62,59,25,51,49 % Powell fell to 33% capacity; 145 ft< full Powell fell to 33% capacity; 145 ft< full % of ave. Powell + 31 feet % of ave. Powell + 31 feet 2006 – 73% of ave – 73% of ave. Is the drought over??? Is the drought over???

UNCERTAINTY OF FUTURE NATURAL FLOW Tree Ring Hydrology Predicts More Significant Droughts Tree Ring Hydrology Predicts More Significant Droughts Climate Change – Warming could reduce the natural flow Climate Change – Warming could reduce the natural flow

Basin States Initiative Shortage plan Shortage plan Coordinated reservoir operations Coordinated reservoir operations Efficiency Efficiency Conservation Conservation Augmentation Augmentation –Weather modification

THE NEED FOR AUGMENTATION Shortage Plan Shortage Plan Coordinated Reservoir Operations Coordinated Reservoir Operations Efficiency Efficiency Conservation Conservation Augmentation – every alternative Augmentation – every alternative –Weather Modification

Upper Colorado River Commission Study Potential Use of Winter Cloud Seeding to Augment the Flow of the Colorado River Potential Use of Winter Cloud Seeding to Augment the Flow of the Colorado River North American Weather Consultants in Sandy Utah North American Weather Consultants in Sandy Utah Don Griffith - Meteorologist Don Griffith - Meteorologist

Recent seeding programs

Identification of Cloud Seeding Potential Existing Areas – to be enhanced and extended Existing Areas – to be enhanced and extended New Potential Areas To Be Seeded New Potential Areas To Be Seeded

Previous Cloud Seeding Studies Namedatewater yield Namedatewater yield –BOR maf –Stanford Res In maf –North Am Wea maf

Study Conclusions Range of expected increase in snowpack 5%-15% Range of expected increase in snowpack 5%-15% Increase in flow from existing seeded = 575,000 ac-ft/yr Increase in flow from existing seeded = 575,000 ac-ft/yr Increase in flow from new seeded 10% = 650,000 ac-ft/yr Increase in flow from new seeded 10% = 650,000 ac-ft/yr Total 10% 1.4 Maf/yr Total 10% 1.4 Maf/yr

STUDY CONCLUSIONS CONT. Estimated cost for new programs – $4.8 million Estimated cost for new programs – $4.8 million Estimated upgrades to existing programs - $2.1 million Estimated upgrades to existing programs - $2.1 million Total cost - $7million Total cost - $7million Cost per acre foot - $5 Cost per acre foot - $5

RECOMMENDATIONS Just Do It Just Do It