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Show EVALUATION OF THE SCIENTIFIC UNDERPINNINGS OF THE MAY 1, 1999 GREAT SALT LAKE PLANNING DOCUMENT LAKE LEVEL FLUCTUATIONS 2. Geologic and historical context a.) The high- level fluctuations that GSL stakeholders should expect to see over time for GSL are: • 4212 feet above sea level - the still- water level of the historic highstand • 4217 feet ~ the still- water highstand level expected in our present climate regime • 4221 feet ~ the unusual but documented highstand of the past 8,000 years. b.) Lake level is intricately tied to global and regional climate. Annual precipitation, cloud cover, wind patterns and temperature affect lake volume through a variety of hydrologic processes, which in turn can affect important ecosystems and socioeconomic factors. Knowledge of the relationship between lake hydrology and global climatic processes should be important to DNR managers, yet there is virtually no mention of climate in the PD. c.) The physical configuration of the lake basin including its natural expansion to the west naturally slows lake level rises dramatically at 4215 - 4217 feet and above. When DNR plans for flooding to 4217 feet it is respecting a danger that is possible within our present climate regime. d.) Flooding damage will occur above the still- stand level due to storm action, groundwater effects and changes in foundation properties. e.) The PD does not discuss drought as a serious concern. DNR should expect GSL to decline to levels equal to or lower than those of the 1960s with attendant problems. As with highstands, the timing of lowstands of the lake is uncertain. f.) DNR has not succeeded in getting other federal, state and local agencies to recognize and respect lake level fluctuations. The PD does not acknowledge that DNR is the most logical agency to provide leadership and influence entities to recognize flooding hazards and accept risks when they build on the lake's flood plain. g.) The concept of management zones based on elevation of GSL makes sense. At some lake levels public safety is more at risk than at others. At some levels cultural resources are more impacted, etc. 223 |