9 Comparison to UGS data

The patterns of salinity and Gilbert Bay elevation observed in Figures 7.1 and 7.2 and 7.3 are also consistent with those from an independent dataset provided by UGS (Figures 9.1 and 9.2). This dataset includes a longer time series of density data from a wider range of lake elevations. It also demonstrates that in addition to the changes observed following the breach opening, the conditions observed in both the pre (2010 - 2016) breach and post (2017 - present) time periods are likely different from historical observations (Figure 9.1).
These data are available for download via geology.utah.gov/docs/xls/GSL_brine_chem_db.xlsx.

Figure 9.1: Gilbert Bay surface (depth <= 3 ft) density (UGS data, combined active sites).

Figure 9.2: Comparisons of density to WSE relationships among UGS and USGS datasets.

Figure 9.3: Salinity estimated from UGS density measurements via USGS empirical model formula as presented in the CMMP compared to modeled salinity thresholds. Note that these are not bathymetrically weighted values as used in evaluating permit performance.