Triggering Criteria

The City of Greenville Water Conservation and Drought Contingency Plan establishes certain "triggers" that move progressively, from voluntary conservation to mandatory conservation stages. Once certain demand levels are reached, water conservation stages are triggered.

Stage 1


REQUIREMENTS FOR INITIATION
When two or more of the following criteria are met:

City reservoir levels 532.5' (sea level) and falling
Lake Tawakoni level 434' and falling
PDSI* Moderate drought (-2.0 to -2.9)
Reservoir recharge frequency Two times in the past 12 months
Water Demand 60% of Water Production Plant capacity (7.8 MGD**)
*Palmer Drought Severity Index
**Million Gallons per Day

Stage 1 Water Restrictions

Stage 2


REQUIREMENTS FOR INITIATION
When two or more of the following criteria are met:

City reservoir levels 531.5' (sea level) and falling
Lake Tawakoni level 432' and falling
PDSI* Severe drought (-3.0 to -3.9)
Reservoir recharge frequency One time in the past 12 months
Water Demand 70% of Water Production Plant capacity (9.1 MGD**)
*Palmer Drought Severity Index
**Million Gallons per Day

Stage 2 Water Restrictions

Stage 3


REQUIREMENTS FOR INITIATION
When two or more of the following criteria are met:

City reservoir levels 531.5' (sea level) and falling
Lake Tawakoni level 431' and falling
PDSI* Extreme drought (-4.0 or less)
Reservoir recharge frequency Zero times in the past 12 months
Water Demand 80% of Water Production Plant capacity (10.4 MGD**)
*Palmer Drought Severity Index
**Million Gallons per Day

Stage 3 Water Restrictions

Stage 4


REQUIREMENTS FOR INITIATION
When four of the triggering criteria in Stage 3 are met or when the City Manager declares a critical water shortage.

Stage 4 Water Restrictions

Stage 5


REQUIREMENTS FOR INITIATION
  • When all five of the triggering criteria in Stage 3 are met
  • Major water line breaks, or pump or system failures occur, which cause unprecedented loss of capability to provide water service
  • Natural or man-made contamination of the water supply source(s)
Stage 5 Water Restrictions