k, so the commercial river season is starting to heat up and so are things at gcmrc. On top of our regular schedule we will be adding trips to study the effects of the Low Summer Steady Flow (lssf) experiment (marked with *) which as of this time has been “tentatively” approved. Due to the increased flurry of activity, I have been unable to collect project “blurbs” as in last quarter's bqr—sorry. The schedule of trips I have listed is definitely subject to change at any moment's notice. Hopefully, this will give you some idea of the trips you may encounter in the busy season this year. As always, I encourage everyone to make contact with trips you may encounter. They will be very busy but are open to sharing information about their projects with you and your folks. Let's keep those lines of communication wide open!
Now what about this Low Summer Steady Flow experiment…what's that all about?

The Reasonable and Prudent Alternative (rpa) of the Fish and Wildlife Service's 1994 Biological Opinion (bo) on operation of Glen Canyon Dam contains an element (1.a) that addresses a program of experimental flows for endangered native fish. These experimental flows are to occur during low water years of approximately 8.23 million acre feet (maf) delivery to the Lower Colorado River Basin. The purpose is to verify an effective flow regime for management of endangered fish of the Colorado River in Glen and Grand Canyons. In January 2000, Reclamation identified that, for the first time since the bo was accepted, projected inflows to Lake Powell were anticipated to be low enough to conduct a test of the rpa 1.a hydrograph intended to benefit endangered fish.

The hydrograph proposed and now tentatively scheduled will include flows of steady 19,000 for the months of April and May with a spike of 31,000 for four days from May 2–5. At the end of May the flows will drop to 13,500 for three days and then to steady 8,000 until the end of September. There will be a second spike of 31,000 for four days September 5–9. The hypothesis to be tested by this hydrograph is based on the idea that high flows in the spring timed with native fish spawning will increase and stabilize habitat at the mouths of tributaries. The summer steady flows provide a warmer and more stable mainstream habitat to promote survivorship and overall health of the native fish population, followed by a fall spike to impact the non-native (predatory/competing) fish population.
This is obviously an incredibly oversimplified view of what its all about, but hey, now you'll at least have some idea of why you're down there dinging those props this summer. Good Luck!
You can contact me at (520) 556-7207 or email at cfritz@flagmail.wr.usgs.gov.

Fritz