t's that time of year again. The Adopt-a-Beach (aab) Program saw another great season and produced some interesting new results. First, it's nice to work on a study where the input is so varied, creative and enthusiastic. And as always, gcrg sends a huge thanks to everyone who adopted a beach and added his or her input of information in 1999. It's simple: the study could not be done without you.
Last year, the most critical goal of the program was to bring it back from an uncertain fate; participation had dwindled to less than half of that of 1996. The good news is that the numbers went back up this year. Ten more beaches were adopted in 1999 than in 1998, and the study benefited from a much greater spread of data not only from increased numbers, but also in the beaches that were adopted. (More beaches were chosen that had not been chosen in 1997 and 1998, helping to put the whole study set back in balance).
This last weekend at the gts more folks signed up to adopt a beach for the 2000 summer season than in any of the last three years! Forty-one beaches were claimed within a couple of hours on Sunday, and there are still a few beaches left that need adopters. The program could still use the help of anyone who would like to adopt a beach for the 2000 summer season. Here's why:

1) Due to low flow projections for this summer (i.e., 8–15,000 cfs all summer) many of the camps in the aab study set will show greater exposure than they would during standard (up to 20,000) flow schedules. This will enable trips to camp on newly exposed, lower elevation surfaces that have formed as eddy deposits or “bench” areas at many camps. If we can get lots of photographs of all of the beaches, it may be possible to determine new information about the effects of visitation and lower-stage fluctuating flows on these “new”campable areas. In addition, this low water effect may encourage more use of camps that are uncampable or undesirable at more common higher fluctuating flows (such as Clear Creek, Talking Heads, or Olo).
2) The more repeat photographs we receive for each individual beach, the better. Because some adopters can only do a couple of trips, its great to double up and really get a lot of visual and written information about every site.

Is change slowing over time?
The most significant observation made this year is that beaches are showing an apparent increase in relative stability over time. It's difficult to document this effect without numerical data, but photographs and guide comments have shown trends in support of it. For example, in the year following the 1996 Beach/Habitat Building Flow (bhbf), beaches showed a fairly rapid decrease in size throughout the system, with a far lesser amount showing little or no change. This was more apparent in some beaches (i.e., Owl Eyes, Tuckup, Salt Water Wash, Tatahatso) than in others. During 1997, beaches continued to decrease in size at a significant rate (that is, photographs still showed very noticeable decrease in size throughout the summer). Some photos from the 1997 season show the most dramatic erosion to beachfronts for all years of the study, in response to continuous high flows during mid-summer and in November 1997. In 1998, decrease was still visible at many beaches, but we had to look very critically at each photo to tell for sure; the number of beaches showing no change was climbing, and the number showing decrease was beginning to fall. In 1999, more beaches remained unchanged than in all previous years (1996–98).
Regardless of the cause of this general trend, repeat photography of Grand Canyon camping beaches supports the observation that magnitude of decrease in beach size is more pronounced in the time shortly after a beach rebuilding flow, than in the time long after a rebuilding flow. This was also reflected in the trend of some of the results over the full four seasons of the study. The amount of dynamic change is less noticeable over time.

1999 Results
There was very good photographic coverage of adopted beaches in the 1999 summer season. The most evident trend was the increase in the number of beaches that showed very little if any change. The greatest concentration of these stable beaches was in the Muav Gorge critical reach (rm 131–167). The greatest concentration of beaches that decreased in size was located in the Upper Gorge critical reach (rm 76–116). But, in Marble Canyon (rm 8–42) and the whole system, the proportion was almost half and half.
The general observation of change in the off-season (November 1, 1998–March 31, 1999) followed a similar trend. Since 1996, every off-season has shown a lesser amount of beaches that decreased relative to those that showed little if any change.
The longevity of high elevation sand deposited by the bhbf was assessed again in 1999. (The number of beaches in the study set that are still benefiting from deposition in that high flow event, and those that have degraded back to, or close to, their pre-flood condition.) The results showed that, of the beaches measured in 1999, more of them showed a return to their pre-flood condition than in all previous years of the study.
Every year an assessment is made to determine what processes are most responsible for the decreased size, and in what areas of the corridor. Previously (1996–1998), results have been somewhat similar. Generally, guide comments and photos verified that cutbank formation due to fluctuating flow releases had the largest effect, regardless of the critical reach. In 1997 gully formation due to rainfall events and side canyon flashes was a significant mechanism. Effects due to visitation, wind, or unknown processes have played a lesser role. This year (1999), results were somewhat different. Throughout the corridor, rainfall gully formation played the dominant role in decreasing beach size, although the greatest concentration was seen in the Upper Gorge critical reach. This was evident at places like Schist, Granite, Hermit, 120 mile and Stone, although unfortunately the rephotography at Stone Creek did not reflect the large flash flood event that occurred there in July. Also notable was an increase from previous years in the effect of visitation to beaches that was reported by guides. As in previous years, effects due to wind or other effects was less significant.

Vegetative encroachment?
We were interested in determining if the rephotography would show an increase in vegetation at camps. A complication arose in that photographs of many beaches show only a narrow portion of the beach front; a view of the whole camp would better serve to assess if increased vegetation were becoming a problem for the quality of campsite access. Still, about half of the beaches showed a slight increase in vegetation visible in the photos, while far fewer showed a large increase. So far, guides have not indicated in this study that it's even an issue. We'd love to hear more from you about this.

Finally, we want to thank everyone (heartily) who adopted a beach in 1999 (and every year), and all of you who promptly signed up at the April gts to adopt beaches for the 2000 season. It's exciting to have almost all of the study set again under the stewardship of guides (including an unprecedented participation by folks in the science community and the Park Service). We still have room for more adopters—please give us a call and we'll send out a packet in time for your first trip. I want to mention again and again that the program is completely dependent on your participation, and the results that have been directed through the Adaptive Management Program are due completely to all of your hard work in photographing and commenting on the condition of our camping beached this year and every year. Of course, we want to extend our gratitude to our contributors, the Grand Canyon Conservation Fund, and the Grand Canyon Monitoring and Research Center for their generous contributions to the program.

For further clarification of the statistics and methods of analysis employed in this study, please refer to the forthcoming final report of the 1999 results of the Adopt-a-Beach Program. As always, it will be sent to adopters, pertinent agencies and interested parties.

Gary O'Brien