The District established the Dover/Plant City Water Use Caution Area (D/PCWUCA) and a Recovery Strategy to address issues that followed an “unprecedented” cold event in 2010. An area assessment done in 2020 indicated that the Recovery Strategy was no longer needed, and in 2021, the District’s Governing Board approved rulemaking to eliminate the Recovery Strategy.
In January 2010 there was a cold-weather event in the Dover/Plant City area when temperatures dropped below 34 degrees for nine nights over an 11-day period.
For local farmers, it is common practice to spray water on their crops during cold protection events, which is referred to as crop protection. The main crops in this area that require crop protection are strawberries, citrus, blueberries and plant nurseries.
Approximately 892 million gallons per day of water was used during this 11-day period to protect crops. This significantly lowered the aquifer level and created many unforeseen problems. About 750 wells were negatively affected and 140 sinkholes formed in the area causing about $8 million in damages. To address these issues, the District established the D/PCWUCA which encompasses 259 square miles.
Dover/Plant City Water Use Caution Area (D/PCWUCA)
The D/PCWUCA established restrictions for new Upper Floridan Aquifer groundwater withdrawals used for crop protection, new standards for well construction, and incentive programs to encourage growers to use best management practices for cold protection through the Facilitating Agricultural Resource Management Systems (FARMS) program. In addition, a Minimum Aquifer Level Protection Zone (MALPZ) encompassing approximately 66 square miles was also established within the water use caution area where no new cold protection quantities were allocated. A summary of the protective measures that were implemented are outlined below:
- Daily restrictions were placed on groundwater withdrawals used for cold protection within the MALPZ and surrounding area.
- Well construction permitting requirements were established for wells drilled within and surrounding the D/PCWUCA. New wells are to be constructed to better standards, avoiding future potential cold protection impacts.
- The District grants up to 75% funding for projects that decrease groundwater use for cold protection within the D/PCWUCA through the FARMS program.
- The District created a tool to better assign well pumping responsibility to water use permittees, so that domestic well owners in the area who are adversely affected by cold protection events are appropriately mitigated by permittees.
- The District also improved its ability to monitor groundwater levels in “real-time” in the recovery area and to react to cold protection events by installing automatic meter reading devices on all cold protection withdrawals. Data from these devices is collected by the District and used to better understand and predict water usage.
- The District improved its notification system to growers in the area of potential cold protection events to allow growers more time to prepare.
2020 Area Assessment
The District conducted a comprehensive analysis of the area in 2020 that evaluated a variety of key trends. The assessment concluded that in the D/PCWUCA there has been an air temperature warming trend over the past 128 years and there is an ongoing and projected decrease in agricultural land and water use due to urbanization. Additionally, it was determined that the minimum aquifer level had been achieved through an evaluation completed with an updated computer modeling design event that captured 95 percent of the cold protection events that have been observed since the late-1800s. Based on the assessed trends and minimum aquifer level achievement status, the District reevaluated the need for a Recovery Strategy.
The District also assessed the January 2010 freeze event that promoted the establishment of the Recovery Strategy. Using area temperature records, including one station with 128 years of data, it was estimated that the chance of this event reoccurring was once in approximately 570 years. Given the results of this temperature evaluation, staff concluded that it was inappropriate to base recovery strategy criterion on such an unprecedented event. Based on this determination and on the status assessment utilizing the updated modeling design event and the trends that were identified in the analysis, District staff recommended that the Recovery Strategy be eliminated. The D/PCWUCA and its associated protective measures, however, were recommended to remain in place due to the geologic, climatic and agricultural conditions present in this area. As a result, the District’s Governing Board approved the necessary rule making to eliminate the Recovery Strategy at its 2021 August meeting.
The District will ensure the same protective measures implemented when the D/PCWUCA was developed remain in place to reduce resource impacts from occurring due to potential groundwater withdrawals during future cold protection events. In addition to the protective measures previously identified, the District will continue to conduct annual minimum aquifer level status assessments to monitor the effects of cold protection groundwater withdrawals, agricultural use trends, new sinkhole formations in the area, and dry well reports. The FARMS program will continue to provide incentives to decrease the use of groundwater for cold protection and other crop production quantities in this area. If trends change when annual assessments are completed, the District will consider whether the approach needs to be adjusted.