Glen Canyon Dam Adaptive Management Program Administrative History

Federal advisory committees — which may also be designated as commissions, councils, or task forces — are created as provisional advisory bodies that can circumvent bureaucratic constraints to collect a variety of viewpoints on specific policy issues. Advisory bodies have been created to address a host of issues, ranging from policies on organ donation to the design and implementation of the Department of Homeland Security. These committees are often created to help the government manage and solve complex or divisive issues. Such committees may be mandated to render independent advice or make recommendations to various bodies within the federal government by congressional statute, created by presidential executive order, or required by fiat of an agency head.

Congress formally acknowledged the merits of using advisory committees to acquire viewpoints from business, academic, governmental, and other interests when it passed the Federal Advisory Committee Act (FACA) in 1972 (5 U.S.C. Appendix — Federal Advisory Committee Act; 86 Stat.770, as amended). Enactment of FACA was prompted by the belief of many citizens and Members of Congress that such committees were duplicative, inefficient, and lacked adequate control or oversight. Additionally, some citizens believed the committees failed to sufficiently represent the public interest — an opinion punctuated by the closed-door meeting policies of many committees. FACA mandated certain structural and operational requirements for many federal committees, including formal reporting and oversight procedures for the advisory bodies. FACA requires that committee membership be “fairly balanced in terms of the points of view represented,” and advice provided by committees be objective and accessible to the public. Additionally, FACA requires nearly all committee meetings be open to the public. Pursuant to statute, the General Services Administration (GSA) maintains and administers management guidelines for federal advisory committees. During FY2008, GSA reported a total of 917 active committees with nearly 64,000 total members that provided advice and recommendations to 50 federal agencies. The total operating costs for these committees in FY2008 was $344.3 million. Agency administrators, the President, and Congress continue to create federal advisory committees in the 111th Congress.

Committees that fit certain FACA criteria and are created by the executive branch are governed by FACA guidelines. FACA was designed to eliminate duplication of committee expertise and make advisory bodies in the executive branch more transparent. Congress may decide, however, to place FACA requirements on a body that it statutorily created. Existing statutes are sometimes unclear as to whether a congressionally created committee would have to comply with FACA requirements — except in cases when the statute explicitly mandates FACA’s applicability.

Legislation (H.R. 1320) was reintroduced in the 111th Congress that would require members of advisory committees be selected without regard to their partisan affiliation. Also pursuant to the legislation, executive branch agency heads would be authorized to require members serving on agency advisory committees to fully disclose any actual or potential conflicts of interest. Additionally, GSA’s Administrator would be given authority to create regulations and guidelines to further ensure that an advisory committee offered impartial advice and recommendations. The bill would also require each advisory committee to create a website, publish advance notice of meetings, and provide public access to proceedings on its website. The bill was sent to the House Committee on Oversight and Government Reform, and ordered to be reported from the committee on March 10, 2009. Similar legislation was introduced in the 110th Congress (H.R. 5687), but was not enacted.

Between 1999 and 2005, drought in the western United States led to a >44 m fall in the level of Lake Powell (Arizona-Utah), the nation's second-largest reservoir. River discharges to the reservoir were halved, yet the rivers still incised the tops of deltas left exposed along the rim of the reservoir by the lake-level fall. Erosion of the deltas enriched the rivers in sediment such that upon entering the reservoir they discharged plunging subaqueous gravity flows, one of which was imaged acoustically. Repeat bathymetric surveys of the reservoir show that the gravity flows overtopped rockfalls and formed small subaqueous fans, locally raising sediment accumulation rates 10–100-fold. The timing of deep-basin deposition differed regionally across the reservoir with respect to lake-level change. Total mass of sediment transferred from the lake perimeter to its bottom equates to ~22 yr of river input.

It is apparent that before emplacement of the dam gully degradation in terraces was restored by periodic alluvial deposition from river floods, but perhaps even more important is the redistribution of flood sands onto higher terraces by wind. Thus, we propose the term "restorative base-level hypothesis" to emphasize the dynamic equilibrium between gully erosion and renewed deposition, a process that remains active in Cataract Canyon but is disrupted in Grand Canyon by the presence and operation of the dam.

We developed type geomorphic settings to develop a conceptual process model for the diverse small-catchment geomorphic system in Grand Canyon. Research findings explain how streams are able to cross broad, flat terraces given a rainfall event and how they become progressively more integrated with the river. The primary channelization processes are ponding and overflow, alluvial fan progradation, and infiltration and piping, all of which contribute to nickpoint migration. An understanding of these processes was essential to building the geomorphic model.

The predictive mathematical model quantifies erosional vulnerability by applying a hypothetical rainfall event of 25 mm/hour onto a catchment above a "pristine" terrace sequence. The principal driving factor for erosion is basin area. The principal resisting factor for erosion is terrace diffusion capacity, which is a function of terrace sand cross-sectional area and infiltration capacity. Several important modifying factors are applied to the basic model to determine relative vulnerability of each terrace to gully erosion. Vulnerability of the top terrace at each catchment is plotted against the measured amount of gully erosion in that terrace, providing a base line against which progressive changes in gully depth can be easily monitored in the future.

Field studies and research show that: (1) gully erosion of terraces has been severe during the past 20 years in Grand Canyon due to unusually high precipitation; and (2) sediment deprivation coupled with the lack of large annual floods has caused a reduction in restorative (depositional) factors. Continued measurement and documentation of geomorphic processes in catchments, particularly at type geomorphic settings, will further refine and verify the predictability of the model. We conclude that beach-habitat-building flows are essential for initiating natural restorative processes and that one of the most important processes in gully mitigation may be eolian reworking of newly deposited flood sands onto higher terraces. Prior to the construction of Glen Canyon Dam, gully-deepening and river/wind depositional processes were in dynamic equilibrium, allowing the preservation of ancient cultural sites for the past several thousand years.