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How Climate Change Affects Local Water Supply

One of the most detrimental aspects of climate change is the damage that it causes to water supply systems. One way that manifests itself is with a shortage of actual water because the water supply is not being replenished by rain. Droughts, an increasing phenomenon in New Hampshire, are another aspect of that damage. Between the years 2000 and 2020, drought conditions were present for 11 years. According to New Hampshire’s Department of Environmental Services from mid-July to mid-June the state received 25% to 50% of normal precipitation. As a result, New Hampshire Public Radio finds that “the vast majority of New Hampshire is in a moderate drought, with towns and cities bordering Massachusetts experiencing a severe drought, according to the most recent update from the U.S. Drought Monitor.” A cause for future concern about droughts in New Hampshire is not a relief either. The National Oceanic and Atmospheric Administration affirm that the drought outlook for our state will continue into the future. Almost assuredly, should there be more emissions at higher rates in the future, drought probability and conditions will worsen as time goes on.


The consequences of climate change in NH are becoming obvious, especially across the state’s southwestern region, where the drought is most serious. According to the New Hampshire Department of Environmental Services, seventy-two community water systems, as well as six municipalities have outdoor water use restrictions in place as of August 10th. These restrictions affect around 219,900 people across the state. In addition, Lebanon also prohibits landscape and lawn watering between the hours of 8 AM and 7 PM. All across New Hampshire, cities are forced to conserve their dwindling water supply. We really are not seeing the levels of rain that we need to see.

Global warming is also affecting snowfall in NH. Taking a step back to the US as a whole, almost 80% of the continental United States has experienced less snow since 1930, according to the Environmental Protection Agency. As NHPR’s Mara Hoplamazian writes, “climate change causes warmer and shorter winters, we may see less snow in many places, including New Hampshire. And some places are already starting to experience significantly less snow accumulation than normal.” In fact, that’s exactly what we see. The Carsey School of Public Policy found that New Hampshire’s winter temperatures have risen by around 4 degrees since around 1900. While that might mean more snowfall simply due to an expanded capacity for holding moisture, (the Carsey school finds that with each 1°F rise in temperature, the atmosphere can hold 4 percent more moisture) as well as the fact that snow is more likely around 32 degrees, (climate change can take the coldest days and put them in the optimal snow sweet spot) making snowfall potentially more likely. However, that window is not a permanent one, because if temperatures keep rising, then snow will just become rain. Optimal snowfall spots aside, the duration of snow cover on the ground at any given time is invariably shortened with rising temperatures. We indeed see such a phenomenon, as across the Northeast, there is a 12 to 45 day decrease in snow-covered days from 1917 to 2016. This is seriously bad news for half of New Hampshire residents who use private wells as their water source at home, as they rely on groundwater (a water source that is recharged by rain) that would be deleteriously impacted by less snow being around for less time.

The harm of there being literally less water brought on by climate change is not the only one. The warming also means that there are more cyanobacteria in our water supplies. Cyanobacteria is a bacteria that, if consumed, can cause damage to the brain, spinal cord, kidneys, and liver. It has also been found to be a skin irritant. Unsurprisingly, they have been found to cause illness in humans and animals alike. The National Library of Medicine dictates that “climatic changes (e.g. global warming, hydrologic changes, increased frequencies and intensities of tropical cyclones, more intense and persistent droughts), strongly affect cyanobacterial growth and bloom potentials in freshwater and marine ecosystems.” In the context of cyanobacteria, researchers further that climate change poses “a formidable challenge to water quality (and) water supply.” As a result, early blooms of cyanobacteria have been discovered in the public water supplies of Salem and Lebanon. This increase in heat is letting very harmful bacteria grow in the water that we drink every day, bacteria that damage our brains, kidneys, and livers. The future for cyanobacteria is not an optimistic one; as summers get warmer, professor emeritus at UNH Jim Haney says that those blooms have more of a chance to thrive.


In conclusion, climate change is threatening both the quantity and quality of New Hampshire’s water supply. Increased droughts are depleting both public water supplies and wells. Meanwhile, rising temperatures have meant that harmful bacteria are working their way into our water. Pure and simple: the water we wash with and drink every day is becoming less plentiful and less safe.



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