Arizona water supply

Lake Mead has series of small earthquakes

The earth, for all its faults, adjusts to changing conditions. One of those changing conditions is more water entering Lake Mead. Over the past two months or so, there has been a series of small earthquakes, magnitude 2.1-2.5, in the Lake Mead area.

State geologist Lee Allison opines that these quakes are “due to the load on the rocks under the reservoir as the late, and large, snow pack runoff in the Rockies is filling the lake.” (See also)

According to the Las Vegas Review-Journal, meltwater from heavy snowfall last winter is filling the reservoirs:

The river system that fills Lake Mead and supplies 90 percent of Las Vegas’ drinking water is on track for its third wettest year since Lake Powell was filled for the first time in 1963.

The surface of Lake Powell has risen to its highest level in a decade…

The surface of Lake Mead is now 20 feet higher than it was a year ago, and current projections — ones now likely to be adjusted upward — call for it to rise another 33 feet by Aug. 1, 2012.

Last month’s inflow ranked as the second largest Lake Powell has ever seen in July. The 4.35 million acre-feet of water that poured into the reservoir on the Utah-Arizona border that month was almost three times the July average, and the flow in June was even greater — 5.4 million acre-feet, or almost 24 times the amount of water used in the Las Vegas Valley all of last year.


In other news:

The Arizona Geological Survey is currently featuring a video about the 7.4 magnitude Sonoran earthquake of 1887 which also shook southern Arizona.


For more information on earthquakes, see:

Where the Next Big American Earthquake and Tsunami Might Occur

Spanish Scientists Find Technique to Predict Earthquakes Claiming 80% Accuracy

The Measure of an Earthquake

Local atmospheric changes may foretell large earthquakes

Earth Fissures in Arizona

A home buyer’s guide to geologic hazards

For a brief history of Arizona geology, see my seven-part series:

Arizona Geologic History: Chapter 1, Precambrian Time When Arizona was at the South Pole

Arizona Geological History: Chapter 2, Cambrian and Ordovician Time

Arizona Geological History: Chapter 3: Devonian to Permian Time

Arizona Geological History Chapter 4: Triassic Period

Arizona Geological History Chapter 5: Jurassic Time

Arizona Geological History 6, The Cretaceous Period

Arizona Geological History 7: The Cenozoic Era




Tucson’s Water Action Plan, Fuzzy Sustainable Development

The City of Tucson and Pima County are collaborating on a region water plan. It’s about time. But you should read the reports: government concepts of priorities might not be the same as those held by property owners and businesses.

Over the past several years, local governments have been devising a plan to maintain and ensure water supply for the future. A “Phase 1” report deals with an inventory of water resources and an assessment of infrastructure. A “Phase 2” report “establishes a framework for sustainable water resources planning including 19 goals and 56 recommendations within four interconnected elements: Water Supply, Demand Management, Comprehensive Integrated Planning, and Respect for Environment.”

The new Action Plan describes a range of activities with time lines to implement the goals and

recommendations in the Phase 2 Report. The City wants your comments.

From my reading of the plan, the City is placing great emphasis on making the Santa Cruz River pretty. That will include riparian restoration projects, a new bureaucracy to propose such projects, and bond elections to buy up land. The report uses fuzzy phrases such as “smart growth” and “sustainable development.” Concerning sustainability, the report admits, ” Our work during Phase I documented how elusive the concept is in practice.”

The Action Plan cites four principles for managing water:

Principle 1: Water is an essential part of life for humans and the environment. Delivery of water and wastewater must maximize both quantity and quality.

Principle 2: The environment must be considered a user, not simply a provider, of water resources.

Principle 3: Policies affecting water and wastewater must be open to wide public discussion in a completely transparent process.

Principle 4: Water is an economically-valued resource and must be managed with due consideration to its economic value.

Your comments are needed to help the City go from concepts to practice.

For some additional background, please read my posts: Water Supply and Demand in Tucson, and How Much Water is There.