Streamflow Depletion: A Challenge for the Neponset
During August 2010, flows in the Neponset River fell to 88% below normal during a relatively modest dry spell. Tributaries have run dry. The Neponset is one of the state’s most “hydrologically stressed” rivers.
Artificially low summer water levels in the Neponset river and its tributaries impact the health of fish and wildlife, reduce or at times eliminate recreational use of the river, lead to more concentrated pollution levels in times of low flow, and suggest that some of our water supplies may not be reliable during periods of serious drought.
Water withdrawals, sewer systems and paved surfaces all contribute to the Neponset's problem with reduced flow in the summer. Fortunately, it is possible
to restore more natural streamflows in the Neponset Watershed. Read on to learn more about the causes of this problem, what NepRWA is doing to improve the situation, the encouraging progress that has already been made, and what you personally can do to help restore the Neponset's
flow.
The Natural Water Cycle: Groundwater Kept Us Flowing
Before the Neponset Watershed was developed, our rain fell on forests and meadows during dozens of small storms each year.
About half that rain was taken up by plants and evaporated. Another 10-20%, ran off quickly into nearby streams during larger storms.
The remaining 30-40% soaked into the ground, refilled underground areas of sand and gravel known as aquifers, and then flowed underground gradually toward the river where it re-emerged
to flow cool and steady, contributing to the “base flow” of the river during the dry summer months.
The Neponset’s Man-made Water Cycle
In the Neponset Watershed, we have dramatically altered the natural water cycle. The result is a loss of dry-weather flow in the river, which seriously impacts wildlife, water quality and recreation.
More Withdrawals
More than 160,000 people draw water from the Neponset’s underground aquifers for drinking and
other uses, with some 16 million gallons per day of permitted withdrawals. Most of it
never is returned, instead getting piped to far-away sewer treatment plants or evaporating from lawns. Another 18 million gallons per day
leak into cracked and aging sewers, destined for the same distant treatment plants.
Fewer Deposits
At the same time, we have reduced the amount of water that soaks into the
ground by constructing some 28 square miles of roads, parking lots and other “impervious surfaces” in the watershed. These paved areas reduce groundwater recharge by some
11 million gallons per day.
Changing Rainfall Patterns
Adding to the concern, climate change
already has begun to change historic patterns of rainfall, recharge and evaporation—shifting us toward warmer temperatures which makes for more evaporation, along with larger and less frequent storms, which make for more runoff, less groundwater recharge and more frequent summer droughts.
Restoring our Water Balance
The good news is that there is enormous opportunity to restore the river by making our drinking water, wastewater and stormwater infrastructure more efficient. We can:
Manage wastewater locally instead of sending it to distant treatment plants.
Make homes and businesses more efficient.
Stop water from leaking into sewers.
Clean up polluted runoff and send it back into the ground.
Change at the Top
NepRWA is advocating for legislative and policy changes at the state level by partnering with groups from across the state to press for the adoption streamflow standards that will put us on a more sustainable path.
Implementing Locally
But policy change from above won’t be enough. NepRWA’s strength is in working directly with our 14 cities and towns to help modernize our infrastructure, educate the public and our young people, and enable all of us to use water more sustainably.
Progress Underway
Sharon’s water use has dropped by 20%, thanks to a sustained conservation program, in partnership with NepRWA. The program has reduced Sharon’s operating costs, helping keep water bills low and avoiding millions in potential supply expansion costs, all while protecting the river. NepRWA is undertaking similar efforts in Canton, Milton, Stoughton, and has done past work along these lines in Walpole.
NepRWA
also is working with Canton, Dedham, Milton, Sharon, Stoughton and Walpole to begin designing and installing rain gardens and infiltration basins and other measures to clean polluted runoff and put it back in the ground.
Our Streamflow Action Plan
Partner with at least six towns to plan and implement water conservation efforts.
Evaluate town efforts to reduce water leaking into sewers. Advocate for more state and federal requirements and funding to address sewer leaks.
Advocate for enforceable streamflow standards and stronger stormwater management requirements.
Work with cities and towns to accelerate the retrofitting of streets & parking lots to send more clean runoff back into the ground.
What You Can Do
Support NepRWA’s Streamflow Action Plan by
making
a donation. Donations from individuals are critical to this work!
With a donation during spring 2011, you automatically will be
entered into a sweepstakes
to win a kayak!
Upgrade fixtures to
save water at home.
Let state and federal officials know that you care about clean water and healthy streams.
Vote in your local elections and participate at your town
meeting; not all of our towns have embraced water efficiency yet!
Questions?
Contact us at 781-575-0354 or staff@neponset.org.
