Welcome back to my weekly fishing report!
It’s been an interesting couple of weeks, as my blog/fishing report page got hacked by some scoundrel! I’m back and should be able to post my fishing report regularly!
May water flows released from Glen Canyon Dam have started and we received an update from the Park Service about the new “bug flows” which started May 1st and are planned to continue through August. When we first heard about the proposed bug flows in a AZ Game & Fish meeting in March, we were excited that the government and power authorities were going to work together to help the fishery. Last week we received the following email update:
Beginning May 1st and continuing through August 31, 2018, the Department of the Interior will conduct the first experimental flow at Glen Canyon Dam since completing the Long-Term Experimental and Management Plan in December 2016. The experimental flows, referred to as “bug flows” are intended to provide enhanced habitat for the life-cycle of aquatic insects that are the primary food source for fish in the Colorado River. The flows will change the schedule and flow rates of water releases from Lake Powell through Glen Canyon Dam on weekends during the experimental period.
Bug Flows consist of steady weekend releases from Glen Canyon Dam and normal fluctuating releases during the weekdays. The steady weekend flows are expected to provide favorable conditions for insects to lay eggs along the Colorado River downstream of Glen Canyon Dam, while the minimum flows on weekdays are designed to be similar to flows on the weekends. This flow regime would decrease the amount of stage change in the river on the weekends, thus preventing the insect eggs that are laid along the river margins from drying out.
A Bug Flows hydrograph that incorporates weekend steady low flow releases that are 1,000 cubic feet per second (cfs) higher than weekday low flow releases in all months (May – August) is proposed for initial testing. The recommended hydrograph was developed collaboratively by the Grand Canyon Monitoring and Research Center and Western Area Power Administration, using an optimization process that determined a 1,000 cfs increase in weekend flows provides the best egg-laying conditions, river-wide, across all months. To meet downstream water delivery requirements, the stable, low flows on weekends need to be offset by relatively higher peak flows during the week than would otherwise be achieved under normal operations.
Steady low-flow releases on weekends would begin after the normal down-ramp on Friday evening, with the down-ramp ending when flow releases match the designed Bug Flows weekend steady low flow. Dam releases would be steady throughout (except for system regulation and use of reserves) Saturday and Sunday and then dip briefly Monday morning for hydropower scheduling purposes to the designed weekday low flow, prior to ramping up at the normal rate until peaking later on Monday at the designed weekday high flow. Releases throughout the remainder of the week (Tuesday – Friday) would then be similar to releases on Monday. The exact timing of each of these peaks and low flow troughs varies from month to month according to scheduled monthly release volumes.
This is the most exciting news for the fishery that we’ve heard for a long time. The intention of the bug flows is to help aquatic insects by leveling water releases so the insect eggs will not dry out and die as happens when water releases highly fluctuate. That the various agencies are interested in improving the fishery is a major victory for the fishery and we are all eagerly watching the results of the more stable flows. Everyone expects the aquatic food base to benefit from the bug flow which ideally will provide more food for the fish, and should result in bigger, healthier fish. One can only hope that it will also improve the dry fly fishing!
Fishing the first week of May was inconsistent, with a full moon early in the week, coupled with a couple weather fronts that made fishing tough for the early part of the week. As weather stabilized and the fish got acclimated to the new May water releases, fishing picked up dramatically! Top flies continue to be midges, (zebra midge, x midge) and ginger scuds.
Spin fishing was also impacted by the elements and also improved over the weekend. Expect fishing to be great during the bug flow experiment!