The North Texas Municipal Water District announced that their water supply region will go back to once weekly landscape irrigation during September and October. The once weekly watering schedule for the City of Allen begins Sunday, August 31 and runs through October 31. Your designated watering day will not change. The day you water now will be the same day you can water on a weekly basis. Please refer to the updated water schedule map to determine the watering day for your neighborhood. Once November begins, the regular Stage 3 seasonal watering schedule of twice a month is effective through March 31.
Once weekly watering is being allowed to address the impact that the drought and lower water usage has created for ensuring water quality. Because the increased consumption from once weekly landscape irrigation will lower lake levels two to three feet, it is still important to water only if needed on your allowed watering day. We must have winter rainfall to fill our lakes before we can declare an end to the current drought and the related need for water use restrictions. If residents do not have rain and freeze sensors, we ask that you turn off automatic irrigation systems and use the system once weekly in the manual mode if needed on your one allowed watering day per week.
More About the Factors Impacting Water Quality and Treatment Practices
For public health reasons, all water systems are required to maintain a minimum level of chloramine (a disinfectant) to control undesirable bacterial growth in the water system. During the heat of the summer, treated water and storage tank temperatures rise causing the disinfectant levels to drop much faster than in the winter months. Normally, this is not an issue because cities move much more water through their systems in summer months due to landscape irrigation demands so that water is moving through the system before the disinfectant levels drop significantly due to heat. Water use in Allen would normally be three times more in the summer months than in the winter months.
With the reduced water usage this summer, it has been more difficult for all NTMWD member and customer cities to maintain disinfectant levels throughout the distribution system. In order to maintain water quality, city staff must add disinfectant at both ground and elevated storage tanks and must line flush in specific areas of low disinfectant concentration. This has worked to maintain safe and healthy water quality. However, as an alternative to the significant amount of line flushing that has been required, NTMWD decided to allow once weekly landscape irrigation to generate the higher water use currently needed to maintain disinfectant levels.