4 Inflows and lake elevation

The opening of the causeway breach was followed by several years of high tributary inflows to the lake in 2017 (Figure 4.1). Following closure of the east causeway culvert in late 2013, about a 3 foot head difference developed between Gilbert and Gunnison Bays (Figure 4.2). This head difference was rapidly relieved (in ~6 months) following the opening of the causeway breach in December 2016. Since the initial head difference was relieved, annual elevations of Gilbert and Gunnison Bays have been relatively stable (excepting seasonal fluctuations). Head difference has also stabilized at around 0.5-1 foot, fairly consistent with historic observations.

4.1 Inflows

Figure 4.1: Approximate monthly flows of major GSL tributaries.

4.2 Elevation

Figure 4.2: Gilbert and Gunnison Bay water surface elevation.