uring each of the last two summer seasons, river guides have continued to support the Adopt-a-Beach (aab) program. For all of those who made that stop at their beach, trip after trip, in 1997 and 1998, the program benefited greatly and is still alive and well. As in 1996, guides adopted beaches chosen from the original set of 44, within the three critical reaches‹stretches of river where beaches are scarce, highly eroded and/or frequently visited: Marble Canyon (rm 8­41), Upper Gorge (rm 75­114), and Muav Gorge (rm 130­167). Guides photographed the beaches and made observations about their condition. In 1997 and 1998, they were asked questions like: what were the effects of the high, continuous flows of 1997? How was this different from 1998, a season of predominantly fluctuating flows? What exactly happened in these two years following the 1996 beach/habitat building flow (1996 flood flow)? What are the lasting effects of the 1996 flood flow, two years later?

Originally, Adopt-a-Beach was designed as a program that incorporated the interest and on-the-ground experience of guides in contributing to scientific and monitoring work on Grand Canyon sand bars. The impetus for the original study was to observe the effects of the 1996 flood flow. In 1997 and 1998, the methods of analysis stayed much the same. Not only were results of beach change produced for each of the two years, but a new mission for the program has begun to crystallize as a result of the most recent study. Looking into the future, the need was recognized for aab to assume the role of an annual monitoring study which focuses not only on discrete events such as the 1996 flood flow, but which also observes change to beaches based on the full year of observation (winter and summer seasons). In this way, data can be linked throughout all years of the study, and long-term observations are made possible.

This forward-looking perspective for aab is important for a couple of reasons. First, as a program designed and run by guides, we all need a way to see the fruits of our contributions. The health of Grand Canyon beaches is something that is important to all of us, and by adopting a beach we each add important data that creates resolution in the whole study, and enables the big picture to become clear year after year. Next, the program integrates the efforts of guides, their investment of time and knowledge, with ongoing scientific monitoring. Aab annual results provide the Grand Canyon Monitoring and Research Center (gcmrc) with important information. Gcmrc and other interested parties submit recommendations to the Adaptive Management Workgroup, which advises the Secretary of the Interior in questions of river management policy. (The Protocol Evaluation Program of gcmrc gave Adopt-a-Beach a very favorable review in its meeting summary of August 1998.) Aab also provides the public with direct knowledge about the health of the Canyon¹s beaches. The connection between guides, scientists, and the public helps to increase awareness about a place we¹re all concerned about.

So what happened to the beaches in 1997­98?We needed to link up the new data to the 1996 results, so both years were observed during four periods: the winter season of ¹96/¹97 (November 1­March 31), the summer season of 1997 (April 1­October 31), and the same periods for the winter season of ¹97/¹98, and the summer season of 1998. Of the original 44 beaches selected in 1996, 40 were adopted in 1997, and 21 adopted in 1998.

ln a nutshell, we saw the following trends, which were consistent throughout both years of the study. First, very little if any increase in beach size occurred. Guides reported that any new deposition of sand was observed only on the flat bench areas below the fluctuating flow level. This made camping easier at several ³low water² camps, such as Zoroaster and Stone Creek; others showed improvement to low level beachfronts and parking areas.

Overall, beaches showed evidence of equilibrating to the various flow schedules imposed on them during the two years. The four periods of continuous, high flows during 1997 appeared to erode sand from beachfronts at the high flow levels, and to deposit sand in the eddy areas. Subsequent lower flows and higher ranging fluctuating flows evidently cut back new deposits, eroding or redistributing sand into the lower elevation eddy areas. The magnitude of visible change was more dramatic during 1997, especially due to cutbank formation. Beaches in 1998 appeared to suffer less impact overall, despite a return to season-long fluctuating flows.

What caused the changes to beaches that guides could see? Far and away, beaches showed either a decrease in size or little change at all. For several beaches, we couldn¹t tell what happened due to photographic positions that had been moved. In 1997, 65% of beaches showed a decrease in size, while 25% showed minimal change. In 1998, only 43% decreased in size, while 48% remained the same. Of beaches that showed decrease for both years, the leading cause was cutbank formation due to fluctuating flows. In 1997, this impact accounted for decrease in 73­84% of beaches, within the three critical reaches. During 1998, the effect of fluctuating flows was more varied system-wide, affecting 33% of beaches in Marble Canyon, 57% in Upper Gorge, and 87% in Muav Gorge.

Tributary flashfloods and gullying by rainfall were big, visible events changing beaches in both years, especially in 1997. Bishops, Lower Tuna, Garnet, Bass Camp, Matkat Hotel, and Last Chance (among others) all took big hits during monsoon events of 1997. In these cases, campable area was significantly reduced or even eliminated (Upper Garnet), except at low water. Human visitation and scouring by wind played lesser roles in reducing beach size, but guides noticed that foot traffic appeared to have aided in beach front stability over time at several camps.

Some good news: When compared to pre-flood photos taken in March 1996, more than half of beaches (50% in 1997 and 52% in 1998) still showed to be in better shape than their pre-flood condition, at the end of each of the two summer seasons. 28% in 1997 and 38% in 1998 appear to have returned to, or gotten worse than their pre-flood condition. This is based on the amount of sand visible in photographs, which usually shows only the beachfront. The positive long-term effect of the 1996 flood flow may be even greater: due to lack of pre-flood photos for several beaches, or because of switched photo positions, we couldn¹t determine the condition of 22% of beaches in 1997, and 9% in 1998.

These were only some of the compiled results. Full results will be available via the gcrg 1997­98 Adopt-a-Beach report, available as of this writing. Gcrg would like to again thank the Grand Canyon Conservation Fund (a non-profit grant making program, established and managed by Grand Canyon River Outfitters) and the Grand Canyon Monitoring and Research Center for funding support of this program. We also wish to express huge thanks to everyone who adopted a beach during the past three years. We¹re looking for adopters again for the 1999 season. This is an important program‹our program. As guides, it¹s an incredibly effective way that we can contribute to our own knowledge of changing conditions of our river camps, and add our voice to the process of ongoing scientific study down there. At this point, it¹s really critical that we keep the program going. For purposes of data analysis, the more beaches that are adopted, the more credible the study. Participation has dropped off (one final stat!) by over 50% since the first year. It¹s understandable that since no report appeared (due to funding difficulties) in 1997, and not much talk was heard by gcrg, we all sort of forgot about Adopt-a-Beach. We want to turn this around, and get back on track. Anyone can adopt a beach from the selected study set. You can participate either by making a tax-deductible contribution of $100 per year, or by volunteering to photograph it. Adopters will receive an annual summary of results including participants. There¹s no limit to how many people can adopt a particular beach, although our goal is to get as many different beaches signed up as possible. The contribution and/or volunteering show a personal commitment to the stewardship of a favorite place, and to the study. The cameras and information packets are ready to go. Contact the gcrg office to sign up.

Gary O'Brien

Thanks to the 1997 and 1998 Adopters