Colorado River: Spring Disturbance Flow

Summary

The Colorado River is crucial for the Southwestern U.S., supplying water to 40 million people and irrigating 5.5 million acres. A 20-year drought has made accurate discharge measurements essential, especially below the Glen Canyon Dam, where recent low-flow releases allowed the USGS to study water levels. Notably, a 185 CFS discrepancy was found 15 miles downstream, prompting extensive measurements using Acoustic Doppler Current Profilers. The data confirmed an average flow of 4,200 CFS with no significant losses, enhancing understanding of the river's vital resources and ensuring effective management for future sustainability.

Takeaways

• 💧 The Colorado River is essential for nearly 40 million people in the Southwestern United States.
• 🌾 It irrigates over 5.5 million acres of land, supporting agriculture in the region.
• ⚡ The river generates upwards of 4,200 megawatts of electrical power each year.
• 📜 Water distribution from the river is governed by various laws, agreements, and treaties.
• 🌵 A 20-year drought has made measuring water discharge from the Glen Canyon Dam crucial for downstream communities.
• 🚰 The average discharge from Glen Canyon Dam is around 12,000 cubic feet per second (CFS).
• 🔧 A recent low-flow release of 4,000 CFS allowed for dam maintenance and data collection.
• 🔍 A notable 185 CFS difference was observed between dam discharge and measurements at Lees Ferry, equating to 83,000 gallons per minute.
• 📏 The study involved extensive discharge measurements using Acoustic Doppler Current Profilers (ADCPs) at five cross-sections.
• 📊 The findings confirmed an average flow of 4,200 CFS with no significant changes over the 15-mile stretch, enhancing water management strategies.

Q & A

What is the significance of the Colorado River to the Southwestern United States?

The Colorado River provides water to nearly 40 million people, irrigates over 5.5 million acres of land, generates billions in revenue from outdoor recreation, and produces upwards of 4,200 megawatts of electrical power per year.

Why is measuring discharge below Glen Canyon Dam important?

Measuring discharge is crucial for downstream communities, especially during periods of drought and low rainfall, to ensure proper water allocation and management.

What was the recent discharge rate released from Glen Canyon Dam?

The Bureau of Reclamation conducted a historically low and steady release of 4,000 cubic feet per second (CFS) from the dam.

What discrepancy was found in the discharge measurements?

A 185 CFS difference was noted between the steady discharge from the dam and the water measured 15 miles downstream at the Lees Ferry gage.

How much water does the 185 CFS difference equate to?

The 185 CFS difference works out to be approximately 83,000 gallons per minute.

What methods were used to investigate the source of the additional water?

Researchers conducted an intensive discharge measuring effort using Acoustic Doppler Current Profilers (ADCPs) at five cross sections between the dam and Lees Ferry to determine the source of the additional water.

How long has it been since similar measurements were taken in this area?

The last opportunity for such intensive measurements has not presented itself in 30 years.

What was the average flow measured at the cross sections?

The data showed an average flow of 4,200 CFS at the measured cross sections.

Was there any significant gain or loss of water measured over the 15-mile reach?

No significant gain or loss of water was measured over the entire 15-mile stretch.

What are the implications of the study for managing Colorado River water resources?

The study confirmed the accuracy of the gaging station and provided valuable data to assist scientists in better accounting for and managing the precious water resources of the Colorado River.