The Reservoir Committee at a Crossroads?

by Steve Miranda

The Reservoir Committee was created nearly 50 years ago to address issues associated with the growing number of reservoirs emerging in the 1950s. During that decade, reservoir construction was rising quickly and reached a peak in the 1960s. At that time freshwater ecology was a relatively young science, although limnology had been around as a discipline for 50 years or more. There were many questions and challenges presented by large reservoirs, which were approached by applying concepts and methods developed by limnologist in freshwater lakes. Lakes (and thus reservoirs) were viewed as waterbodies that functioned for the most part independent from streams and their watersheds. Because each type of water body had unique characteristics and unknowns, they were considered, studied, and managed as independent units. Not surprisingly, the SDAFS established independent committees that dealt with reservoirs and warmwater streams separately.

Since those early days, our understanding of freshwater systems has evolved. In 1980 Vannote et al. published their paper on the river continuum concept. Shortly after in 1983, Ward and Stanford advanced the serial discontinuity concept that predicted and explained the effect of reservoirs along the river continuum. Not much later in 1989, Junk et al. expanded the river continuum concept with the flood pulse concept essentially acknowledging the importance of the horizontal component in many river systems. Once again, Ward and Stanford (1995) expanded the flood pulse concept to account for the effects of modifying floodplain rivers. More recently, Dahm et al. (1998) and Ward et al. (1998) have defined impounded rivers beyond the two dimensional longitudinal and latitudinal space to include the vertical dimension extending from the river bed or floodplain surface down to the bedrock. These developments have positioned reservoirs in their rightful place as part of a large system of water transport. Within this system, biotic and abiotic components including fish interact longitudinally along the main axis of the river, horizontally with the floodplain, and even vertically with the water table and atmosphere.

This view portrays reservoirs as anthropogenic disturbances that affect natural river processes. Proponents of dams contend that their benefits outweigh their costs, that the negative impacts of large dams on the environment are sometimes overstated, that dams often enhance environmental conditions, and that dams are now an essential part of society and critical for human survival. Opponents counteract that the ecological and socioeconomic costs associated with large dams are now recognized, that in many cases these costs outweigh the benefits, and that there are better ways to obtain the services provided by dams. While this debate is taking place in relicensing documents, the scientific literature, courts of law, and in public opinion, society is beginning to take down some of our dams – in fact, just two weeks ago (2/23/2004) the Army Corps of Engineers blew up Embrey Dam in the Rappahannock River, Virginia, with the blessing of the USFWS and VDGIF.

As the Reservoir Committee moves towards developing their 4th symposium it finds itself at a crossroads. Should the committee continue on the straight and narrow path defined in the 1950s, and focus almost exclusively on reservoirs as lake units independent of their watersheds? Or should the committee evolve to think of reservoirs and their fisheries as part of a riverine system whose continuity has been altered by one or many reservoirs?

Some agencies have already faced this decision. For example, TVA once had a large contingent of fisheries biologists that over the years made important contributions to the Reservoir Committee. The agency has substantially reduced their reservoir fisheries staff and shifted their emphasis to watershed and river action teams that take a more integrated approach to river management, relying on partnerships with the public, as well as government and nongovernment organizations that focus on narrow aspects of watershed, river, and reservoir management. That does not mean that reservoir managers must become watershed managers, but simply that they should think about reservoirs as part of a bigger system and should network with those working in the river and watershed. Such redefined conceptualization may in turn produce new directions and solutions to seemingly uncrackable problems.

My position on these issues is evolving. I am personally struggling with matching my training and past accomplishments with the new demands of resource management (just a midlife crisis? – nahhh, I am way past midlife). I encourage you to voice your opinions and begin a dialogue that will help define the role of the upcoming symposium, and that of the Reservoir Committee early in the 21st century. The committee should seriously re-examine its role in view of modern concepts and society’s changing expectations. I suggest the next symposium should be a tool for generating pertinent knowledge required to achieve whichever road is chosen, not an outlet for reverberating the current status of reservoir management.