February 2019 Hydrology Report

Precipitation

The City of Winter Haven received a total of 2.07 inches gross rainfall during February 2019. This amount of precipitation is slightly below the long-term average for February at 2.7 inches, yet well within the normal range. Subtracting the loss of water from the area due to evapotranspiration (ET), the net rainfall for this month totaled at -0.598 inches. The following chart displays the current monthly rainfall for the 2019 year so far (Figure 1). The Year Selector option allows for a visualization of rainfall from previous years.

Figure 1 

Surface Level

The monthly average surface level of the South Chain of Lakes increased from 131.53 ft (NGVD29) in January to 132.05 ft in February of this year. This places the current lake level above the upper normal range for this time of year (131.8 ft). Due to the unseasonably wet weather experienced in the last several months, the Southern Chain has remained high throughout much of the dry season. An increase in lake levels is atypical during the dry season, however the Southeast US is currently experiencing a La Nina weather phenomenon which usually equates to wetter, warmer Winter seasons. Figure 2 illustrates the change of lake levels in response to rainfall.

Figure 2

Groundwater

The surface elevation of the Upper Floridan Aquifer (UFA) increased from 118.4 ft above sea level (NGVD29) in January to 118.54 ft during February. The level of the UFA continues to remain well above the long-term monthly average of 115.78 ft and even persists above the normal range (118.21 ft). An increase in water usage during the dry season (mostly for irrigation), coupled with a lack of replenishing rainfall typically herald a decrease in aquifer levels during Winter months. As previously mentioned, the La Nina event has elicited wet weather which has led to unusually decreased pumping rates and considerable recharge of our water sources. Figure 3 illustrates the current level of the UFA during 2019.

Figure 3