9628

• UCREFRP Catalog Number: 9628
• Author: Gloss, S. P., J. E. Lovich and T. S. Melis.
• Title: The State of the Colorado River Ecosystem in Grand Canyon - A Report of the Grand Canyon Monitoring and Research Center 1991-2004.
• USFW Year: 2005.
• USFW - Doc Type: \
• Copyright Material: NO

12 The State of the Colorado River Ecosystem in Grand Canyon

The Role of Conceptual Modeling in Support of Adaptive
Management in Grand Canyon

One challenge following completion of the 1995 Operation of Glen Canyon Dam Final Environmental Impact
Statement (EIS) was to identify and implement monitoring efforts that would produce scientific data suitable for
evaluating the new operating policy at Glen Canyon Dam. At that time, there was also a sense among managers and
scientists that additional, comprehensive syntheses of available data needed to be undertaken with respect to major
resource categories, such as sediment and fisheries. In addition, the need for development of a conceptual model
for the Colorado River ecosystem, consistent with the adaptive environmental assessment and management process
(now popularly called "adaptive management"), was also identified by the USGS Grand Canyon Monitoring and
Research Center (GCMRC) and its cooperators. This modeling effort began in 1998 and was continued concur-
rently with the establishment of the stakeholder-based, Federal Advisory Committee-the Adaptive Management
Work Group-and the development of the group's strategic goals for the Colorado River ecosystem (1998-2002).
Key objectives for the conceptual modeling exercise were to (I) conduct an exhaustive knowledge assessment of
the various elements of the ecosystem on the basis of existing data and hypotheses posed in the EIS and within
the context of workshops that supported stakeholder and scientist interactions; (2) identify, through this process
of modeling and simulation, key areas where data or knowledge did not exist and therefore were impediments to
developing realistic simulations (by using historical data as a means of verification); and (3) identify future research
directives (both experimental or otherwise) that would effectively fill knowledge gaps in the program related to
management needs.
Development of the physical elements of the conceptual model (the Grand Canyon Model or GCM) proceeded
relatively quickly, mostly because there were abundant data in some key areas (hydrology, sediment, and river flow)
and an operational model for the Colorado River Basin (RiverWare TM) had already been developed by the Bureau
of Reclamation. Other critical areas of the model development, however, were limited by the paucity of available
data related to biology and sociocultural resource areas (\Valters and others, 2000). By 2000, it became clearer that

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1988 Glen Canyon Environmental Studies
issues Glen Canyon Environmental Studies
Final Report, completing Phase I and starting
Phase II, which would be accelerated to support
environmental impact statement process

1

1989 Secretary of the Interior Lujan orders
an environmental impact statement on dam
operations, and National Research Council
sponsors symposium that reviews existing
knowledge on Colorado River ecosystem

1991 Interim operating criteria for
Glen Canyon Dam implemented;
razorback sucker and Kanab ambersnail
(Oxyloma haydeni ssp. kanabensis)
federally listed as endangered