A prominent Ambler land-use planning center has taken on the sizable task of reversing a 30-year trend of flooding and erosion at the Pennypack Creek watershed in an attempt to avoid further damage to the area.
Over the next 29 months, the Center for Sustainable Communities (CSC) at Temple-Ambler will examine the watershed and update its zoning and mapping standards to meet the needs of “mega-mall-type” development taking place in the area.
A $330,000 grant from the William Penn Foundation and $100,000 raised by the 12 municipalities in the watershed will fund the project.
“All the maps are dated right now,” said Dr. Jeffrey Featherstone, director of the CSC and an associate professor for of Community and Regional Planning.
“They tell you where you can build, but you really can’t build there.
“The information on which they (the 12 municipalities of the watershed) developed is outdated. You don’t want people living on floodplains.”
The study, which got underway just a month ago, will entail drafting new floodplain maps, improved planning for storm water management, and zoning changes to improve future development.
It will also seek ways to improve water quality.
Featherstone said the study will “provide the basic information for a storm water plan for the watershed.”
When the study is finished, it will be up to the municipalities — who requested the study — to implement the findings.
Some mapping has already begun, and Ambler engineering students have begun river surveys and cross sections.
Current maps and standards for the watershed are based on information gathered more than 30 years ago, Featherstone said, and the urbanization of the area makes that data obsolete.
As the area develops flooding becomes more of a problem, he said. Instead of water flowing slowly into the creek, it goes to storm sewers, which unleash the water into the creek faster than it can be handled.
During 1999’s Hurricane Floyd, eight people were killed along the banks of the Pennypack when heavy rainstorms caused flooding.
Mike McGhee, manager of Horsham Township — which is in the watershed area — acknowledged urbanization as a problem to the watershed and said he and citizens have become “more sensitive” to it.
“Storms like Hurricane Floyd and Tropical Storm Allison, for example, far exceeded the 100-year flood level,” he said.
Featherstone said reported flood damages in the watershed area are in the range of $7 million to $10 million.
But he estimated the actual damage could be five times higher, because many homes don’t have flood insurance and their damage goes unreported.
Joe Golden, manager of Upper Southampton Township, which is also in the watershed, said his township has 10 to 12 homes in “serious danger of flooding.”
While storms like Floyd and Allison pose the strongest threat, even lesser storms can lead to trouble.
Featherstone said just a few inches of rain can be too much for the Pennypack to handle and continued development only exasperates the problem.
“Unfortunately, we’re seeing [floods] under circumstances much less dramatic.
Anytime you get anything over a couple of inches, you’re going to have problems,” he said.
“Now all of the people downstream who thought they were safe are finding out they are no longer free from flooding.”
While the major concern has been flooding, the water is carrying more pollutants, too.
The Environmental Protection Agency has declared the Pennypack an “impaired stream,” and the CSC study plans to address it with a number of water quality tests.
Doug Brill can be reached at firstname.lastname@example.org.