Steve Oregon challenges the common narrative attributing the low water levels of Lake Powell primarily to climate change's "hot drought" effects. Instead, it highlights various scientific explanations based on hydrology and historical data.
1. Misleading Temperature Claims:
The article argues that claims of a temperature increase of 1.5°F to 2.5°F affecting river flow are misleading. Most river flow comes from high-altitude snow, which does not significantly melt due to minor temperature increases in winter. Sublimation due to warm air temperatures has minimal impact.
2. Model Errors:
The author points out that hydrologic models inaccurately attribute reduced water flow primarily to temperature and ignore other factors like groundwater absorption and dust's impact on snowpack. Major studies indicate that precipitation variability accounts for about 80% of flow variations, contradicting claims that summer temperatures mainly drive flow loss.
3. Ignoring Physical Factors:
Two significant issues that the article terms "water thieves" are high soil moisture levels and dust on snow, which reduce runoff. Healthy soil moisture absorbs water during snowmelt, and dust particles lower the reflectivity of snow, causing it to melt earlier, which subsequently increases evaporation from disturbed soil.
4. Historical Context of Water Use:
The current water use crisis is framed within the context of historical allocation mistakes. The Colorado River Compact overallocated water based on an unusually wet period, which has not been sustained. Current withdrawal rates exceed the river's natural production, leading to drastic drops in reservoir levels.
5. Structural Over-allocation vs. Temperature Effects:
The article emphasizes that Lake Powell's issues stem from structural over-allocation of water and cycles of natural precipitation rather than solely from rising temperatures. Blaming climate change diverts attention from these critical issues that need addressing.
The article concludes that Lake Powell's drying is not primarily the result of rising temperatures and "hot droughts," but rather a combination of over-allocation, historical agricultural practices, and natural climate cycles that have been misrepresented in the media. Understanding these dynamics is essential for effective water management and policy-making.
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