OCR Text |
Show Will having near equal salinities in the north and south arms improve biological productivity? There is insufficientpre- andpost- causeway baseline data ( salt tolerance, nutrient availability, population dynamics, etc.) to support this view one way or another. DWR is currently studying a number of these factors, and it would be prudent to see the outcome of their investigation before decisions are made concerning equalizing the salinities in the north and south arms. Is the railroad obligated to maintain the culverts and breach to allow for bi- directional flow? The state should take action to rectify this situation and enforce its contract with the railroad. The railroad has utilized fill and riprap material to fortify the causeway which has contributed to settling, reduced the permeability of the causeway and as a result reduce bi- directional flow through the causeway. Any attempts to remove debris in the culverts has been unproductive due to natural events like sedimentation and mild storms. Improvements to the causeway should include additional breaches with wing walls on any new and existing culverts to reduce the quick reversal of dredging efforts. Initially, inspections should be conducted at least monthly to determine when it is necessary to clear the culverts. The current situation is based on speculation not fact. The state has not addressed all of the facts regarding salinity in the draft SCCT. The public has been mislead. There is not an increase in salinity of the north arm relative to the south arm. The difference in salinity has not changed from past values when accounting for the influence of the rising and falling lake level. The difference in salinity increases when the lake rises and decreases when the lake level falls. In 1984, the salinity difference decreased in spite of the lake level rising. This deviation from the pattern of the previous 17 years was due to the breach in the causeway and the subsequent 1987- 1989 pumping of north arm brine into the West Desert and north replacement with south arm brine. Both operations reduce the salinity difference. The salinity difference after 1995 is no greater in magnitude or rate of increase than the measurements before 1984. The total salinity mentioned in the SCCT did not account for the effect of salt precipitation in the West Desert or dissolution in the north arm. This uncertainty is removed by analyzing the concentration of a single ion that does not precipitate, such as potassium which indicates no greater difference between the north and south arms of the lake. The UGS measurements of the south and north arm concentrations do not support the current condition in regard to salinity. The salinity disparity is no greater than past measurements and therefore cannot adversely affect the ecosystem any differently than the past 30 years. 284 |