December downpour doubles typical monthly average

December’s weather defied the usual dry trend of this time of year with the districtwide average rainfall more than doubling the typical total. Ten of the 18 counties within the St. Johns River Water Management District region received twice their average, while Duval, Nassau and Baker counties experienced rainfall levels nearing or even tripling their usual December amounts. 

With all the recent rain, it's worth noting that during the cooler months, grass doesn't require frequent watering. Providing one-half to three-quarters of an inch of water every 10–14 days suffices. If your lawn has received substantial rainfall, consider turning off your irrigation system and managing it manually when necessary.

You can evaluate when your grass needs watering by observing specific signs such as folded grass blades, a blue-gray appearance, or slow recovery from footprints.

A full report outlining December’s hydrologic conditions was presented at the District’s Governing Board meeting Jan. 8. Highlights include:

A map illustrates rainfall conditions in December across the St. Johns River Water Management District.

Rainfall

• Districtwide, December’s rainfall averaged 5.56 inches, which is 3 inches above the monthly average.
• County-wide monthly rainfall totals ranged from a high of 8.74 inches in Baker County to a low of 2.69 inches in Okeechobee County.
• Over the past 12 months, rainfall has been near or slightly above average in most of the District.
• Districtwide, the cumulative rainfall total for the past 12 months is 54.41 inches, 3.40 inches above the long-term average. County-wide totals varied between 48.5 inches in Osceola County to 59.1 inches in Volusia County.

Groundwater 

• Upper Floridan aquifer conditions were a mix of mostly high or normal ranges at the end of December.
• Districtwide groundwater levels, expressed as a single index, fall within the 62nd percentile, considered normal for this time of year.

Spring flows

• Silver Springs recorded a mean monthly flow of 697 cubic feet per second (cfs), or 451 million gallons per day (mgd), within the high range for this time of year.
• Blue Spring station in Volusia County reported a mean monthly flow of 161 cfs, or 104 mgd, which falls within the normal range.
• Rock Springs experienced a slight increase in mean monthly flow, remaining in the normal range at 60 cfs (39 mgd).
• Wekiwa Springs also exhibited a slight increase, recording a mean monthly flow of 64 cfs (42 mgd), consistent with the seasonal norm.

For further insights into rainfall totals and other hydrologic data, visit www.sjrwmd.com.

Visit WaterLessFlorida.com for tips to help landscapes thrive while saving water and money. Follow the water conservation conversation at #sjrwmd #waterconservation #savewater.

About the St. Johns River Water Management District 

St. Johns River Water Management District staff are committed to ensuring the sustainable use and protection of water resources for the benefit of the people of the District and the state of Florida. The St. Johns River Water Management District is one of five districts in Florida managing groundwater and surface water supplies in the state. The District encompasses all or part of 18 northeast and east-central Florida counties. District headquarters are in Palatka, and staff are also available to serve the public at Apopka, Jacksonville, and Palm Bay service centers.  

For more information about the District, please visit www.sjrwmd.com.