Changing water flow leads to more bugs in Grand Canyon

May 4, 2019

FLAGSTAFF, Ariz. (AP) — An experiment to change the flow of water from a dam near the Arizona-Utah border has boosted the number of aquatic insects that fish in the Colorado River eat.

Scientists are hoping to better understand those results with a second bug flow experiment that will run through August.

They found that releasing low, steady flows of water from Glen Canyon Dam over the weekends gives bug eggs a better chance at surviving.

The experiment is part of a larger plan to manage operations at the dam, which holds back Lake Powell.

Researchers are recommending three consecutive years of bug flows to see if the amount and types of bugs increase in the Grand Canyon.

The flows don’t change the amount of water that must be delivered to Lake Mead downstream.