The Cape, and much of the northeast really, is in the middle of a pretty significant drought. Ponds, streams, and reservoirs are low, and water levels in wetlands are abnormally low. Drinking water wells are stressed by high summer demand and many towns have finally bowed to reality. Many, but not all towns, now recognize the need to reduce or eliminate non-essential water use to protect the availability of future supplies, to maintain adequate water system operating pressures, and to keep storage tanks filled. While the weather is beyond our control, the factors that exacerbate the shortages reflect the choices that we make.
It is typical for summer water use to be between two to three times higher than the annual average. Part of that increase on Cape Cod has to do with the increase in seasonal population, but the real driver is outdoor irrigation. Water use in homes with irrigated lawns and non-native landscapes is high, and drives seasonal water use to the point where, combined with drought, municipal water supplies are strained. By choosing to plant species that are water hogs or poorly suited to our soil types, property owners are contributing to the problem. Cultivated grasses need a lot of water to stay green and, even when green, provide little or no support to native species and are pretty much biological dead zones. The same goes for many non-native ornamental shrubs and annual flowers; they may look good to you, but their presence strains water resources and crowds out more ecologically beneficial native plants.
There is also a fair bit of confusion about the merits of using private wells to irrigate. Let me be clear, turf irrigation with private wells is a bad idea. Not only does the use of private wells to irrigate non-native plantings have all the drawbacks described above, it also feeds a psychology that undermines the adoption of better water use principles. Seeing the sprinklers going hard at mid-day, when much of the sprayed water evaporates before saturating the soil, makes everyone less inclined to observe wise water use practices. The fact that most people have no way of knowing who is on a municipal supply and who is on a private well adds to the problem, notwithstanding the few yard signs some post that really only provide the veneer of sound environmental practice.
The really big problem with unfettered private well lawn watering is that each private well is a straw sucking water from the same aquifer that feeds our ponds, rivers, wetlands, and municipal wells. While each private well is small, the cumulative effect of thousands of wells taking water and wasting it on watering grass is meaningful. While you may hear that the aquifer is thick and there is plenty of water, the reality is that the upper reaches of the aquifer are what feed vernal pools, recharge wetlands, and feed shallow ponds and streams. Once the water level falls below these resources, they will dry up. Shifting your irrigation from a public water supply to a private well may help you comply with town use restrictions, but it doesn’t help the environment.
You hear it from us all the time: Replace your lawn with more native plantings. Let your lawns go brown in the summer; they will come back as the weather changes. With a more resilient lawn and yard, you will have a sustainable drought resistant landscape that will not need to be watered and can survive a dry summer or two. Irrigating with a public water supply or a private well is just a poor ecological practice. The use of rain barrels and cisterns can extend the use of spring rains to help plants get established or to water food gardens. The most meaningful choice you can, and must make, is to replace your thirsty yard plantings with more native plants that support Cape species and don’t require watering, pesticides, and fertilizers.
