OCR Text |
Show behavior of each other in complex ways. The Planning Document approaches GSL issues based on constituencies. Resources of the lake that have constituencies are well considered in the report while resources that do not have constituencies are not. The lake should be thought of as a complicated set of subsystems rather than as a collection of individual components. Managing the lake as a system recognizes that each management decision impacts the total system. The scientific database to support this kind of systems management should emphasize interactions among the components in addition to the components themselves. 3- Recognize and to the extent possible welcome lake level fluctuations. The idea that the State of Utah can control the lake within a range of a few feet is unrealistic. The Planning Document gives the impression that the State of Utah can control the lake rather than living with its fluctuations. Hydrologically, it is not possible to control lake level changes, nor should stakeholders expect the State to possess or develop a capability to do so. The State should accept occasional flooding and work with other state and federal agencies and local governments to respect and plan for fluctuations in the lake level. Given the time scale on which human activities operate, predictions of the range of lake level fluctuations have some use in the short- term ( 1- 3- year period). Longer- term predications, however, are not reliable enough for planning purposes. The state should assume the lake will rise to the historic high levels ( 4212 ft a. s. l.) during the lifetime of most facilities and that the lake can rise even higher ( 4217 ft. a. s. l.) in today's climate regime. Given that lake level fluctuations will occur, any policy that does not acknowledge probable flooding levels is not on strong scientific footing. 4- The salt balance of the lake is well understood in its broadest terms. The railroad causeway created the dramatic dynamics that determine the salt balance between Gunnison ( north part) and Gilbert ( south part) Bays. In the past few years of rising lake level, Gunnison Bay has gained salt at the expense of Gilbert Bay. This is a transitory and expected phenomenon. However, when the lake is at high levels and declining, there is a net movement of salt from Gunnison Bay into Gilbert Bay. Thus, on the time scale of decades, the difference in salinity between Gunnison and Gilbert Bays is relatively constant. Analyses of lake chemistry by DNR and IMC Kalium, as well as results from a numerical model developed by the U. S. Geological Survey, have been used as tools to understand these dynamic changes in the salt load of the lake. All parties agree that approximately 12% of the total salt load of the lake was lost to the West Desert as a result of pumping from 1987 to 1989. IMC Kalium and the DNR- USGS model differ in their interpretation of the effect of the breach in the causeway and the role of changing causeway permeability. The former concern can probably be resolved using existing data while the latter will require geotechnical information that has not yet been assembled. We have provided details of these issues in our discussion points with the Planning Team. 5- The health of the GSL ecosystems should be of paramount importance. DNR is wise to be concerned about the health of all of the GSL ecosystems. A " healthy" ecosystem can be defined as an ecosystem that is within natural variability; whereas, an 231 |