Water study presented to council
GLOVERSVILLE – Chad Kortz of C.T. Male Associates said Tuesday the groundwater situation in the area near an affordable housing project will not be affected.
“It is possible after a much more detailed study, because it is impossible to know for sure, the Kinderhook project could improve the groundwater situation but it will not have any negative impacts to the groundwater,” Kortz said.
Since the project was proposed in 2009, residents in the area have voiced concerns about it. Particularly, some were concerned the development might exacerbate groundwater problems.
Kort told the Common Council on Tuesday one drainage study of the area around the affordable housing project showed no expected increase in water “ponding” at manhole locations or drains due to the new housing.
Kortz, presenting the findings of the Kinderhook drainage study, said a second storm study did show more stormwater surcharges at two manhole locations.
The study started in the summer of 2012 and Kinderhook Development provided $25,000 for a drainage study in the area of the $11 million affordable-housing project being constructed on the hill at the end of two dead-end streets: Lee Avenue and Northern Terrace.
The 57-acre drainage area studied modeled flow rates for Gloversville based on two rainfall amounts projected over a 24-hour period: 2.3 inches and 3.9 inches. The amounts were the highest rainfall totals in the last year and the last 10 years, respectively.
The analysis considered both pre- and post-construction conditions.
Before the construction, the study showed that during the one-year storm rate, two structures surcharged, and in the 10-year storm rate, a total of nine structures surcharged, Kortz said.
Kortz explained that surcharge means general ponding of water on the surface, usually at manhole locations or drains, and is expected because dumping all stormwater drainage would create problems for others down stream.
“You would expect to see some amount of ponding above those catch basins or manholes,” Kortz said. “This isn’t necessarily unexpected or a problem. Lots of times one of the functions of stroessner systems is to act as a buffer, so that everything doesn’t get downstream so fast that you have a gigantic flooding problem downstream.”
In post-construction conditions, the one-year storm rainfall amount caused the same two structures to surcharge as in the pre-condition analysis.
The 10-year storm rainfall amount made 11 structures surcharge.
The two additional surcharges were on the corner of Brentwood Ave and Lee Avenue and on Lee Avenue.
However, Kortz, said, they were not considered to be alarming.
According to the presentation, the current storm system in the Kinderhook area has 55 catch basins, 22 manholes, 95 pipe sections with pipes ranging from 12 inches to 36 inches in diameter. The system discharges the storm water into the Cayadutta Creek just south of State Street and was installed from 1919 to 1964.
“In general, for a storm system that was constructed from 1919 to 1964 with really no upgrades that we can find it functions quite well,” Kortz said.
“I think it is functioning the way it was designed to,” DPW Director Kevin Jones said at the meeting. “The thing to bare in mind over there is all of those streets have a pretty good slope, so any of that surcharge will run down the street, so it not like it is building a swimming pool in someone’s front yard.”