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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