Providence Journal 3/25/00 Back
By PETER B. LORD Journal Environment Writer
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QUALITY CONTROL: Journal photo/MARY MURPHY |
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Remember last summer's drought? And the torrential rains two summers ago? Both extremes had major and unexpected effects on Rhode Island's lakes and ponds, according to data collected at the University of Rhode Island.
Reports submitted by hundreds of volunteers for URI's Watershed Watch program showed that last summer's drought lowered water levels in some lakes and ponds by 3 feet. Stillwater Pond in Smithfield and Spalding Pond in North Stonington, Conn., were so shallow that volunteers couldn't launch their boats.
The water that remained in some ponds was more polluted than usual because there was less water but the same amount of contaminants. In other ponds, however, the water was clearer because the lack of rainfall meant that contaminants weren't washed into the body.
"The same disparities could be seen after heavy rains, according to Watershed Watch Director Linda T. Green. Sometimes a heavy rain will cleanse a pond. At other times, heavy rain will carry pollutants from nearby land into the pond.
"In 1998, for instance, Rhode Island had 9 inches of rain over three days in June," Green said yesterday. "Coupled with an unusually wet winter and spring, that affected the water quality in many lakes and ponds for the rest of the year."
The rains flushed nutrients out of some ponds, she said, and in some they flushed in nutrients. In others, the rains washed additional matter into the water, causing it to be darker, reducing algae and plant growth on the bottom.
"It's a real challenge to figure out whether apparent changes in water quality are due to weather or due to actual water quality problems or improvements," Green said.
And the weather in the last few years, she conceded, has made that challenge all the greater.
Watershed Watch will release its report on the 1997-98 monitoring seasons at a meeting for volunteers and the public at 7 p.m. Wednesday in Room 273 at URI's Chafee Hall, Kingston.
The report focuses on the impact of weather because 1997 was somewhat average while 1998 was unusually wet. Additional data and anecdotes from last year showed what happens when the weather swings in the other direction, Green said.
Look at the last three Junes and you can understand why people joke about the weather in New England.
Last year, less than a quarter of an inch of rain fell during the entire month. That was the second driest. June in 104 years of record-keeping.
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WATERS MONITORED |
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The following are lakes, ponds and rivers monitored by Watershed Watch. Loca-tions with asterisks (*) have volunteer monitors who are looking for partners to share the monitoring. Sites with two asterisks (**) are those where monitors are especially needed because no one is signed up yet. Children can be monitors if accompanied by adults. If you want to volunteer, call 874-2905. |
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Barrington |
Spring Grove Pond** |
Stillwater Pond* Stafford Pond** Warwick Gorton Pond** Little Pond Sand Pond** Warwick Pond West Greenwich Carr Pond** Mishnock Lake* Tarbox Pond* Tillinghast Pond** Tippencansett Pond** Wickaboxet Pond** Westerly |
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Journal graphic |
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In the previous year, Rhode Island was deluged with so much rainfall a total of 10.27 inches - that overflows of sewage into Narragansett Bay closed some beaches for the July Fourth weekend. It was the second wettest June in recorded history.
You have to go back to 1997 to find a June close to average. A total of 2.3 inches fell then, compared to the average June rainfall of 3.39 inches.
"We always joke that we're still waiting for a year of average weather," Green said yesterday. "1997 was the most average year we've seen in terms of overall temperature and precipitation."
Watershed Watch, now in its 13th year, was one of the first volunteer monitoring groups in the country. Today there are more than 800.
Based at URI's Cooperative Extension Service, Watershed Watch enlists about 250 volunteers who monitor nearly 100 lakes, ponds and rivers in 25 communities.
Some volunteers are regulars, Green said. A teacher at Tolman High School, in Pawtucket, monitors Slater Pond with students from her science class every year. The Girl Scouts regularly monitor Larkin Pond next to their camp in South Kingstown.
More volunteers are needed for the monitoring season, which runs from May to October. Mandatory classroom training is offered the evening of April 6 and the morning of April 8. Field training will be offered in May.
For ponds and lakes, volunteers must have access to a boat that can take them to the middle. They must test water clarity once a week at midday, and test every other week for water temperature, algae and dissolved oxygen. On a few days, they must collect water samples for laboratory analyses.
More information may be obtained by calling Green or volunteer coordinator Elizabeth Herron at 874-2905, or by visiting their Web site at www.edc.uri.edu/uriww.
This year, Watershed Watch has 30 sponsoring organizations. The Surfrider Foundation has joined it this year and offered to monitor a number of popular surfing locations for bacteria.
Constance Corey, who monitors the state's water quality at the Department of Environmental Management, said much of her data comes from the Watershed Watch volunteers, and they do their work so well "we pretty much treat them as if they were DEM people."
The DEM uses the reports to identify pollution problems, Corey said. And soon it will use Watershed Watch data to help set new limits on phosphorous and nitrogen, two triggers of algae growth, in various ponds and lakes.
The biggest discovery of the last few years, Corey said, has been to find out how weather dependent water quality can be.
"The difficulty is trying to tease out what is natural and what is maninduced so that we can regulate it," Corey said.
The reason dry or wet weather can have different effects on different ponds often stems from the way water flows into or out of the pond, Green said.
For instance, Larkin Pond, a kettle-hole pond with no inlet or outlet, is usually very clear. But during last summer's drought "there was a startling decrease in water clarity and algae levels went way up."
Worden's Pond in South Kingstown, usually only 6 feet deep, lost a few feet of depth, but became less clear too, she said.
But Tiogue Lake in Coventry got clearer during the drought.
"One conclusion doesn't fit all," Green said. "That's part of what makes it fascinating, and part of what makes it frustrating."