Item 6A
Item 6A
Ordinance No. 662-C;
Revise the City of Southlake’s Drought Contingency Plan
Drought Contingency Water Conservation
It’s been raining…and raining
So, why a water conservation discussion?
Why drought contingency?
Ellis 109,400 448,600 339,200 310%
Johnson 124,300 444,200 319,900 257%
Kaufman 69,900 277,700 207,800 297%
Parker 85,600 328,400 242,800 284%
Rockwall 42,500 145,000 102,500 241%
Wise 47,600 102,400 54,800 115%
Urban Region 5,067,400 9,107,200 4,039,800 80%
Regional Population
Collin 492,300 1,166,700 674,400 137%
Dallas 2,232,500 2,817,200 584,700
26%
Denton 428,100 1,085,300 657,200 154%
Tarrant 1,435,200 2,291,700 856,500 60%
Water Conservation and Drought Contingency Planning
Water Conservation and Drought Contingency Planning
1997 - State adopted regulations
water systems > 3,300 connection
adopt Water Conservation and Drought Contingency Plans (DCP)
Wholesale purchase from Ft. Worth
Contract terms - require wholesale customers Drought Contingency Plan
At minimum, restrictive as the City of Ft. Worth’s DCP
Water Conservation and Drought Contingency Planning
Southlake’s Drought Contingency Plan
adopted in August, 1996
Revised in January, 2006 (Ord. 622-B)
mirrors the Ft. Worth plan
“triggers” or conditions which warrant the various stages of conservation measures to take effect
all refer to Ft. Worth’s treatment capacity and
the Tarrant Regional Water Districts reservoir capacity
Water Conservation and Drought Contingency Planning
Current DC Plan
does not address specific local water system limitations
limit our ability to meet peak demands
Causes:
Heavy demand
Peak demand – Early a.m.
Drought conditions
Drought Contingency Planning
The two limiting factors in our water systems are the pumping capacity and the elevated storage tank capacity
Drought Contingency Planning
This chart of elevated storage tank levels shows the diurnal water demand for a 4 day period in August 2006
Water Conservation and Drought Contingency Planning
Must maintain sufficient levels of water in the elevated storage tanks
fire protection and domestic use,
Therefore,
Necessary to limit outdoor irrigation
when local water demand causes tower levels to reach critical levels
Potential Problems
High demands
pumping capacity reaches it limits.
water customers demand > pumping capability
probability of emptying EST tanks
pressure drop in the city’s water system.
State regulations,
Pressure drop < 20 pounds psi
Mandatory Issuance of “Boil Water Notice”.
need to build “Local Triggers” into Drought Contingency Plan
Current and Proposed Stages
Stage 1 – Dry Conditions
Stage 2 – Water Watch (<18’ Elev)
Stage 3 – Water Warning (<18’ Elev)
Stage 4 – Emergency Water Management (< 12’ Elev)
Changes
Hypothetical-
Proposed Ordinance
In effect last Summer
Stage 2 Trigger – July 14, 2006
Remained in effect until 9/30/06
Proposed Ordinance Language
If conditions warrant, stand-down from Stages 2, 3 or 4 is available to DPW
Watering Restrictions -10a.m. – 6 p.m.
Remain in Place
SUMMARY
Required by State
Required by Fort Worth
Addition of Local Triggers
High Demand caused
Equipment Malfunction
No Action = Potential Increase of Water outage
Water Conservation and Drought Contingency Planning
Questions?
Water Conservation and Drought Contingency Planning
Stage 1 – Dry Conditions
Normal conservation measures on a voluntary basis
Voluntary lawn and golf course fairway
irrigation recommended once every 5 days with no watering allowed between 10 a.m. and 6 p.m.
Water Conservation and Drought Contingency Planning
Stage 2 – Water Watch
Trigger: Water level in 3 elevated storage tanks falls below 18’ for three consecutive days with the Pearson pump station operating at 100% capacity
Mandatory - Landscape irrigation restricted to once every 5 days
Mandatory - No hosing off of pavement, buildings or windows
Mandatory - Vehicle washing restricted to commercial facilities only
Use of water from Fire Hydrants restricted to fire fighting and uses necessary to maintain public health, safety and welfare
Water Conservation and Drought Contingency Planning
Stage 3 – Water Warning
Trigger: With the Stage 2 restrictions in place for at least 2 weeks, the water level in 3 elevated storage tanks fall below 18’ for three consecutive days with the Pearson pump station
operating at 100% capacity
All Stage 2 restrictions plus the following restrictions apply:
Mandatory - No operation of ornamental fountains
Mandatory - No draining, filling, refilling or adding water to pools or jacuzzi type pools
Mandatory - No foundation watering except by hand held hose and only then on the 5 day watering cycle
Mandatory - Any action allowing water to run onto pavement or otherwise wasting water
Water Conservation and Drought Contingency Planning
Stage 4 – Emergency Water Use Management
Triggers:
With the Stage 3 restrictions in place for at least 2 weeks water level in 3 elevated storage tanks fall below 12’ for three consecutive days with the Pearson pump station operating
at 100% capacity
and/or
malfunction or breakdown of a water system component (pump, storage tank, or supply line) which severely limits the City’s ability to provide water
and/or
At the discretion of the Director of Public Works
Water Conservation and Drought Contingency Planning
Stage 4 – Emergency Water Use Management
All Stage 2 and 3 restrictions plus the following restrictions apply:
NO IRRIGATION
No installation of new landscaping
Water Conservation and Drought Contingency Planning