Item 4G AudioGood evening Honorable Mayor and members of the City
Council. Tonight, We would like to visit with you regarding
the City of Southlake Drought Contingency Plan.
CLICK
1
Pressure Plane serving the remainder of the city. The pressure plane.should help in our ability to keep up with demand in the low reducing the demand on the low pressure plane. This
increased the size of the high pressure plane; thus, During this past Fall and Winter, Public Works staff has experience critical shortages over the past Summer.pressure plane and it
is also the one that we have city. The larger of the 2 pressure planes is the low results from elevation differences in various parts of the requirement to operate the system on 2 pressure
planes majority of the city.serve the low pressure plane which provides water to the Bicentennial, Miron and Dove Elevated Storage Tanks
The City of Fort Worth produces potable drinking water
from several raw water sources such as Eagle Mountain
Lake and Benbook Lake, owned by the Tarrant Regional
Water District. The City of Southlake receives potable
drinking water from the City of Fort Worth through 2
pipelines.
One pipeline is referred to the Caylor Pump Station line.
This is the 42-inch pipeline that was completed and placed
into service last year. The second pipeline is referred to as
the Alta Vista line. Both of these pipelines come into the
western portion of the city and feed 2-5 MG Ground
Storage Tanks. These are the storage tanks located at the
northeast corner of Pearson and FM 1709.
From there, several pumps pump the water in one of two
directions. Some of the water is pumped to the Florence
Elevated Storage Tank and serves the High Pressure
2
Plane. The remaining water is pumped into the Low
Due to high demands during the hot Summer months, our
pumping capacity reaches it limits. This means that during
a peak demand period, our water customers are using
water faster than we can pump the water. When this
occurs for a prolonged period of time, we increase the
probability that we could empty all of the elevated water
storage tanks; thus, resulting in a pressure drop in the
city’s water system.
In accordance with State regulations, should the pressure
20
drop below pounds per square inch, we would be
required to issue a “Boil Water Notice”. Therefore, we
need to build into our Drought Contingency Plan, a vehicle
to mandate a reduction in water consumption should the
demand reach a certain level.
3
The State of Texas requires that all water systems which
serve more than 3300 connections adopt a Water
Conservation and Drought Contingency Plan. The State
adopted this regulation in 1997, requires the adopted plan
to be filed with the Texas Commission on Environmental
Quality and requires a reevaluation every 5 years.
Furthermore, as a condition of our Purchase Agreement
with the City of Fort Worth, we are required to adopt a
Drought Contingency Plan that at a minimum, is as
stringent as theirs.
4
Southlake’s Drought Contingency Plan first went into effect
in August of 1996 and last revised in January of 2006 and
mirrors the Drought Contingency Plan of the City of Fort
Worth.
Today, our plan contains triggers based strictly on City of
Fort Worth or Tarrant Regional Water District parameters
5
…and does not contain triggers reflecting the specific
pumping parameters of the City of Southlake System.
Thus, we occasionally have difficulty in controlling
consumption of water during peak demand periods.
This heavy consumption results from heavy demand from
our customers during the early morning hours.
Consumption is especially high during dry periods and
times of drought.
6
As alluded to earlier in my presentation, our ability to
provide water to our customers is potentially limited by one
of two factors:
•Pumping capacity -Providing more pumps will not help
as will are nearing the pressure class of the pipeline and
the elevated storage tank capacity.
•City Staff is currently working on a study of potential
routes for a line which will provide water to the north side
of the city. In addition, the Master Plan calls for a new
Elevated Storage Tank north of the TW King Pump Station.
This should improve the distribution capabilities of the
city’s system.
7
dropped below 8 feet.
This graph represents the water level in the city’s 4
elevated storage tanks. The water level in each of the
tanks can range from 0 to 40 feet. The vertical axis
represents this range from 0 to 40 feet. The horizontal
axis represents time from left to right.
Each of the city’s 4 tanks is represented by a separate
colored line.
This graph reflects the elevation of water in all four of the
city’s elevated storage tanks over a 4 day period last
Summer. Please notice on the graph that the elevation of
the water in the low pressure plane tanks dropped each
day, reaching their lowest points a little after 8 a.m. each
day.
The Red Arrow indicates a critical point at which on this
8
day the water level in the 3 low pressure plane tanks all
As mentioned earlier, it is essential that we maintain
sufficient levels of water in our elevated storage tanks for a
number of reasons,
•First and foremost, in addition to the city providing water
at adequate pressures for domestic use, we must also be
able to provide water in the event of a fire somewhere in
the city.
•Therefore, it is necessary, during periods of high demand
that we have the ability to mandate a reduction in water
consumption by limiting outdoor irrigation and other water
conservation methods.
9
Our current Drought Contingency Plan has 4 stages. The
proposed Drought Contingency Plan has these same 4
stages.
Efforts are being made to align these stages so that they
are consistent with all North Texas Water Authorities so
that as media picks up on these stages and information is
disseminated in the region, people are not confused.
The names of these stages follow the nomenclature used
for weather related events.
10
•The first stage calls for voluntary water conservation
measures; and,
•irrigation is recommended, but not required to be limited
to once every 5 days.
•Remember, that last year, we were required to amend the
city’s ordinance calling for no irrigation between 10 a.m.
and 6 p.m. from June 1 to September 30 of each year.
11
•addition of the local trigger.Contingency Plan. The only change in Stage No. 2 is the Stage 2 are the same of those under our current Drought Please note that the water conservation
efforts under or the Drought Contingency Stage is escalated.implemented, Stage 2 will remain in effect until October 1 plane elevated water storage tanks. Once Stage 2 is expect that
water levels should rise in the low pressure Once these water conservation measures are in place, we safety and welfare fighting and uses necessary to maintain public health, Finally,
water use from Fire Hydrants is restricted to fire
The 2 nd stage, Water Watch is initiated when the water
level in all 3 lower pressure plane tanks falls below 18 feet
for 3 consecutive days while 3 pumps operating at the
Pearson Pump Station. Pumping with more than 3 pumps
will exceed the pressure rating of the pipe.
Once Stage 2 of the Drought Contingency Plan is
implemented, several mandatory water conservation
measures go into effect:
•Irrigation is limited to once every 5 days;
•No use of water for hosing off of pavement, buildings or
windows;
•Vehicle washing is restricted to commercial facilities only
12
which have water reuse processes; and,
otherwise wasting water is strictly prohibitedaddition of a local trigger. addition of a local trigger. difference in the proposed plan from our current plan is the difference in the
proposed plan from our current plan is the efforts remain the same as those in our current plan. The efforts remain the same as those in our current plan. The Again, as in Stage 2,
the mandatory water conservation Again, as in Stage 2, the mandatory water conservation ••otherwise wasting water is strictly prohibited
Once the water conservation measures resulting from the
implementation of Stage 2 are in place and should the
water elevations once again fall to an elevation of 12 feet
in all 3 low pressure plane elevated storage tanks for 3
consecutive days, Stage 3 with 3 pumps pumping will be
imposed.
In Stage 3 of the proposed Drought Contingency Plan, all
water conservation measures of Stage 2 remain in effect
and the following restrictions go into effect.
••Operation of ornamental fountains must be discontinued;Operation of ornamental fountains must be discontinued;
••No draining, filling, refilling or adding water to pools or No draining, filling, refilling or adding water to pools or
jacuzzi type pools will be allowed;jacuzzi type pools will be allowed;
••Foundation watering will be limited to hand held hose and Foundation watering will be limited to hand held hose and
only then on the 5 day watering cycleonly then on the 5 day watering cycle
13
••Any action allowing water to run onto pavement or Any action allowing water to run onto pavement or
•At the discretion of the Director of Public WorksAt the discretion of the Director of Public Works•
Finally, Stage 4 is referred to as Emergency Water Use
Management. Stage 4 results from a malfunction or
breakdown of a water system component such as a pump,
storage tank or supply line which severely impacts the
operation of the city’s water system.
This Final Stage has 3 triggers:
••Water level in 3 elevated storage tanks fall below 12’ Water level in 3 elevated storage tanks fall below 12’
for three consecutive days with the Pearson pump for three consecutive days with the Pearson pump
station operating at 100% capacity;station operating at 100% capacity;and,orand,or
••malfunction or breakdown of a water system malfunction or breakdown of a water system
component (pump, storage tank, or supply line) which component (pump, storage tank, or supply line) which
severely limits the City’s ability to provide water; and, severely limits the City’s ability to provide water; and,
or,or,
14
In Stage 4, all Stage 2 and 3 water conservation measures
are in effect. In addition, Stage 4 requires:
•NO Landscape Watering;
•As well, as no installation of new landscaping until the
underlying cause of the Stage 4 level is resolved.
15
This chart indicates the schedule that the City of Southlake
will utilize in the event a 5 day watering schedule is
implemented. This is the same watering schedule that is
recommended under Stage 1 –Dry Conditions of the
Drought Contingency Plan.
This is the same watering schedule recommended by City
of Fort Worth and Tarrant Regional Water District. In fact,
this proposed watering scheduled is used by most water
authorities in the North Texas Region.
Please note that this is the same schedule that is used
throughout North Texas and remains the same as is our
current plan.
16
Just a quick summary…
The Drought Contingency Plan is required by the State of
Texas and the City of Fort Worth, from whom we purchase
water from.
The proposed Drought Contingency Plan calls for the
addition of “Local Triggers” resulting from High local
demand that exceeds the systems pumping limitations or
in the case of Stage 4. an equipment malfunction
Without the addition of these local triggers, the potential for
running out of water in the city is increased.
17
18
19