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Florida Administrative Code (Last Updated: October 28, 2024) |
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40. Water Management Districts |
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40C. St. Johns River Water Management District |
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40C-21. The Water Shortage Plan |
1(1) This rule sets forth the manner in which the District will periodically evaluate water conditions within the District. Data thereby generated assists the District in determining whether and to what extent a water shortage should be declared.
39(2) Monitoring data – Water data and water demand data will be obtained from any source of information needed to evaluate the following:
62(a) Drought Indicators shown in Table 21-1.
69(b) Current regional 72surface water flows 75and lake levels and their relationship to low normal values.
85(c) Current and recent values of the U.S. Drought Monitor for the National Drought Mitigation Center.
101(d) Current precipitation outlooks from the Climate Prediction Center of the National Oceanic and Atmospheric Administration’s National Weather Service.
120(e) Public supply storage status.
125(3) In evaluating whether or not a Water Shortage or Water Shortage Emergency should be declared, the following evaluation process is followed:
147(a) The District will compare current data to values for specific Drought Indicators as shown in Table 21-1.
165(b) The District will compile these comparisons and consider Drought Condition Levels as shown in Table 21-2 and the factors identified in paragraphs 18840C-21.251(4)(a)-189(i), F.A.C., to determine the appropriate Drought Condition Level.
198(c) This evaluation will occur on at least a monthly basis.
209TABLE 21-1: Drought Indicators
213DROUGHT INDICATOR VALUE
216REGIONAL RAINFALL
218(12-Month Moving Sum)
221REGIONAL RAINFALL
223(24-Month Moving Sum)
226GROUND WATER LEVELS*
229Moderate
23012-month rainfall at or below: 40 inches
23724-month rainfall at or below: 84 inches
244At or below 15th percentile
249Severe
25012-month rainfall
252at or below: 35 inches
25724-month rainfall
259at or below: 79 inches
264At or below 10th percentile
269Extreme
27012-month rainfall
272at or below: 30 inches or 4-week duration of rainfall at or below the severe indicator
28824-month rainfall
290at or below: 74 inches or 4-week duration of rainfall at or below the severe indicator
306At or below 10th percentile for greater than 4 weeks
316Critical
31712-month rainfall
319at or below: 25 inches or 8-week duration of rainfall at or below severe indicator
33424-month rainfall
336at or below: 69 inches or 8-week duration at or below severe indicator
349At or below 10th percentile for greater than 8 weeks
359* Calculated based on at least 30 years of historical data
370TABLE 21-2: 372Drought Condition Levels
375Drought Condition Level
378Drought Indicator Values
381Moderate
382At least two Drought Indicator Values are Moderate
390Severe
391All Drought Indicator Values are Moderate or at least one is Severe
403Extreme
404Two or more Drought Indicator Values are Severe or at least one is Extreme
418Critical
419Two or more Drought Indicator Values are Extreme or at least one is Critical
433Rulemaking Authority 435373.044, 436373.113 FS. 438Law Implemented 440373.175, 441373.246 FS. 443History–New 1-1-84, Amended 9-16-92, 6-7-93, 8-23-18.
