OCR Text |
Show Figure 6. Water- salt balance model simulation results with present conditions. Simulation results for present conditions show a very different picture. North arm salinity remains near saturation to south arm elevation 4201 feet while south arm salinity varies from about ocean salinity of three percent at an elevation of 4192 feet to a peak of nearly ten percent at 4202 feet. This simulation assumed that the culverts were completely plugged and that the salt load of the present lake is 600 million tons less than that for the simulation of figure 5. The causeway modeled in this run has about twenty percent of the permeability of the simulation in figure 5 for water level elevations 4200 and about eighty percent of the permeability above that point. The model results tell us that while the culverts are significant to the salt balance of the lake, that they alone are not adequate to provide the circulation necessary for a properly functioning lake. Figure 7 shows the simulation of present conditions but with the culverts cleaned. Note that south arm salinity is somewhat higher, but never reaches the range that is typically associated with ideal brine shrimp production. The extreme freshening of the lake shown in figure 6 at lower lake elevations was not evident in this simulation. 368 |