As we head into summer, thoughts of green lawns and lush landscaping come to mind. The warm weather months ahead will increase our outdoor activities—and our water use—dramatically. Daily residential water use in our area is approximately 140 gallons per person. Water utilization is typically relegated to indoor use during the cold winter months, with less than 4 percent used for actual consumption. Remarkably, during the summer, average water usage skyrockets to 200 gallons per person per day, as illustrated in the graph below: So, what causes this dramatic increase in water use when the weather gets warm? Hot and dry weather, coupled with our desire to keep our lawns nice and green, has always been the primary culprit. However, over the past three decades, the installation of automatic underground lawn irrigation systems has contributed significantly to escalated summertime water use. Such systems have become prevalent as a means to increase real estate values, as residents place a higher emphasis on property beautification through landscaping investment and maintenance. The ease of use and automatic operation of irrigation systems make lawn and landscape watering a simple task that requires little thought and effort. Since water costs in our region tend to be very low when compared to other utilities, there is little incentive to conserve our precious natural resource. However, long-term changes in weather patterns can significantly impact our groundwater resources.
All we need to do is look to the west coast and take note of the significant effects of the drought in California. During the 1960s, Long Island experienced a similar long-term drought that drastically lowered groundwater elevations. In this era of climate change, history can and probably will repeat itself. Therefore, now is the time to develop good habits and simple sustainable practices that will promote more efficient use of our vital drinking water supply. Studies disseminated by local Cornell Cooperative Extensions have concluded that lawns tend to be over-irrigated. These studies determined that the irrigation of lawns every other day at a rate of one inch per week is sufficient for most areas. Because of the significant water use associated with lawn irrigation, sprinkling your lawn rather than soaking it is a simple, logical way to promote efficient use of the drinking water supply. Start by watering every other day rather than every day. Daily watering is not necessary, and too much water can do more harm than good, promoting lawn fungus and increasing runoff to storm sewers.
To minimize water loss through evaporation, avoid irrigating on windy days and when temperatures are highest (generally mid-day, between the hours of 10:00 a.m. and 4:00 p.m.). You can also take advantage of simple, low-cost technologies that promote water sustainability. The use of smart controllers and sensors on lawn irrigation systems will automatically adjust water usage based on weather and soil conditions. These sensors can override an automated timer and shut the system down during rain events. Similarly, moisture sensors can detect moisture levels in the soil and override the system controller to avoid over-watering. Don’t be surprised if you come across an app for this purpose in the near future! Practicing outdoor water sustainability is simple, cost-effective, and smart. It all starts with you and your lawn. Saving water today will ensure an abundant supply now and well into the future. Paul Granger, P.E., is Vice President of H2M Water. He can be reached at firstname.lastname@example.org.