Stormwater design for development meets criteria
Lower Towamensing Township hopes water runoff concerns at a gated community have been alleviated.
Township engineer Greg Haas of Carbon Engineering, spoke with the township's board of supervisors on Tuesday about the Boulder Oaks Development to be built by Brian Stroup.
Haas said the Boulder Oaks Section 3 plan consists of a 24-lot subdivision adjacent to the current Boulder Oaks Development. The stormwater, in its existing condition, runs to the north, he said.
A design engineer analyzed the site, and a sub-water shed was created for the top part of the mountain that conservatively calculated predeveloped runoff and routed that down the side of the hill, Haas said.
As a result, Haas said "the predeveloped flows are calculated to be more conservative than if the entire watershed would be included."
To handle drainage in the post-developed condition, Haas said they have composed a treatment that is comprised of three large basins that will collect the water. For each rain event, there's going to be a certain amount of runoff retained in each basin, he said.
The net result is a decrease in the discharge rates as per the township's Subdivision and Land Development Ordinance (SALDO) for the two through 100 year storm events, Haas said.
"The design met all the criteria of the SALDO," Haas said. "Even with the underestimation, we felt the design was very conservative and there shouldn't be any effects."
In several instances, Haas said he believes the conditions should be improved because the development of the property will divert water away from those properties that currently have drainage issues.
Supervisors Chairman Ron Walbert said the a thorough review was done on the development.
"We didn't haphazardly pass this development," Walbert said. "The Planning Commission did its due diligence."
Last month, supervisors fielded various questions from several property owners fearful of major water runoff from the development.
Nanovic said at that time the developer has to meet the requirements of the township's SALDO, and has to build it according to the plans.
The subdivision has received conditional preliminary plan approval up to this point.