It’s been over a year already, but memories of the aftermath of Tropical Storm Ida are fresh for many in Greenwich whose properties were damaged by water.
About 30 residents of Pemberwick turned out for a meeting at town hall on Nov 9 that was led by deputy DPW commissioner Jim Michel and attended by engineers from DPW and CDM Smith, plus DPW commissioner Amy Siebert and First Selectman Fred Camillo.
In the high intensity, short duration rain storm in the overnight hours between Sept 1 and 2, 2021, residents in Pemberwick were slammed particularly hard by water – water not just from the Byram River, which has a history of flooding, but by water that came down a steep hill from the area of West Lyon Farm and shot across Pemberwick Park to wreak havoc on streets including Rex, Luxy, Dale Drive, Lucy and Monica Road.
At the time, residents said they were familiar with the rise and fall of the Byram River. Some property owners at lower elevations close to the river are in flood zones and were already required to be insured.
But the flooding on Sept 1 was different, they said, and they were not insured from the water that came from above via Pemberwick Park and over Pemberwick Road.
Residents lost their furnaces, hot water heaters, washers and dryers, refrigerators and freezers.
In the days of clean up following the flood, Stella Roberto, who moved to 2 Dale Drive in October 1966, said her house was not in the flood zone and she was not required to have flood insurance.
She said her house had only had two previous floods, which she attributed to the development of West Lyon Farm.
“The first flood came in 1977, when West Lyon Farm was under construction. We had no run off before then. My husband grew up next door. They never had a problem with water up at Lyon Farm. Water came up from the river, but it never reached here.”
“Then, March 2, 2007, we had our second flood,” she recalled.
The third flood was in those terrifying overnight hours between Sept 1st and 2nd, 2021.
In addition to pointing a finger at West Lyon Farm Drive, she said the trash rack behind Pemberwick Park’s home base was too small and was jammed with debris because DPW had not properly tended to it.
The “trash rack” is the metal grate at the opening of the pipe that takes water down the hill and under Pemberwick Park to the Byram River.
Army Corps of Engineers Byram River Project Versus Town Projects
Mr. Michel said the September 2021 flood was preceded by 3-1/2 inches of rain that had already saturated the ground. In addition, Ida had a peak of almost 4 inches in a 2-hour period.
He said rain fell from 6:00pm to midnight, with a really big peak right around 9:00 pm.
“That really taxed the storm systems,” he said.
He went on to show maps of the Byram River watershed area which comprises more than 15 square miles. The watershed funnels down through Pemberwick, which is just 1.6 square miles.
Mr. Michel said the Army Corps of Engineers project was a long time in the making.
“They came through with a study. They looked at the entire Pemberwick area. They started the project in 2012, got to the solution stage in 2018. As part of looking at that project they looked at flood proofing, levees, detention basins, dredging…and selected a plan to modify the bridges at Route 1,” Mr. Michel explained. “That is their tentative plan, and it has funding through the federal government.”
Mr. Michel described that news was nothing short of miraculous.
He cautioned residents that the Army Corps project was not a cure-all.
“Even after this project, they still are anticipating there will be damages during flood events. That’s something to remember,” he said.
Greenwich DPW Study
In 2022 DPW focused on what happened in Pemberwick Park and what how the drainage pipes were functioning.
They considered many things including creating storage on Pemberwick Field and dredging Caroline Pond.
They also reviewed West Lyon Farm.
“We took this project and went very detailed. People are asking when will there be answers. When will we see things built?” Mr. Michel said.
However, he explained, “We want to see what is the most efficient use of town funding. We took this project and went on a very micro scale looking at every last little detail and modeled it in different ways.”
Replacing the Trash Rack
Mr. Michel said the trash rack took a pretty good hit with debris in September 2021. And alongside a huge rut was created by water circling around the stone walls rather than funneling through the drainage pipe.
He shared photos of a forested area upstream, where storm water had washed away soil and exposed roots of trees that he said would ultimately die.
He said based on DPW studies, the recommendation is to replace the trash rack, extend wing walls, and raise the headwall height.
Also, he said, given the pipes were undersized on Rex street, his department was looking to update the pipe network under the park, down through Rex Street and out to the Byram River.
However, he said because of utility lines underground, it would be a challenge to install a 60″ pipe. Instead, DPW was considering installing two pipes side by side. The goal is to accommodate a 100 year storm, with a 1% chance of happening every year.
“That tells us we’ll be working with the parks group to do better maintenance on the upstream. We don’t want to eliminate the entire forest. That’s not reasonable. It’s good for absorbing the rainfall and taking in rainfall. We need to do better maintenance of the streambed. We’ll work with parks.”
Jim Michel, Dept of Public Works Deputy Commissioner
DPW is also considering building a berm on the back side of the park and letting the park collect water. But, he said, “We’re not sold on this option.”
“We don’t know if it can accommodate the volume of water coming down. But it may be an additional safety measure we implement as we finalize our design.”
As for the West Lyon Farm retention ponds, Mr. Michel said the ponds were “functioning well and doing the job they were intended to do.”
“The run off from West Lyon Farm is not the reason for the flooding,” he said. “We identified a couple minor modifications West Lyon Farm can do, and they are receptive to working with us to make some minor improvements.”
Mr. Michel dismissed the idea of dredging Caroline Pond as a method to alleviate flooding.
“Dredging of a pond is an aesthetic improvement. It does not improve the storm water capacity of a drainage system,” he said. “We could dredge it but it won’t increase capacity.”
Flood Risk Reduction: A Shared Responsibility
Mr. Michel explained that FEMA and the Army Corps of Engineers focus on a structure’s first floor elevation when damages are assessed.
“They don’t consider basements,” he said, adding that a collaborative approach is required with property owners. “Everyone has to work together.”
“Repetitive losses are rarely covered by FEMA. If there is one, and 10 years later there is another, they expect after the first claim, that things are done to your property. You use the first claim to rebuild it so it won’t happen again.”
Jim Michel – DPW Deputy Commissioner
Mr. Michel said property owners, especially in the area of Homestead, Hollow Wood and Den Lane which are at lower, were encouraged to raise their homes, even after the Army Corps project comes through. He also said they were encouraged to get utilities out of their basements and to create flood vents to allow water to pass underneath a home’s foundation.
Another suggestion was to install dry flood proofing, which involves building a barrier in front of doorways to prevent water coming during a flood or installing a “ring wall” which essentially is a wall around an entire property.
He said raising a home did not mean it had to be “ugly on stilts.” Instead, the area under the elevated house is enclosed and not used for mechanicals.
Timeline
• Finalize design of pipe expansion from Rex Street to Byram River: Winter ‘22
• Work with West Lyon Farm: Winter 22
• Trash rack improvements: Spring 23
• Pipe expansion: Summer 23
Public Comment
Carl Griffasi of Cross Street said he was pleased to hear the trash rack would be replaced.
He said insurance rates in his neighborhood had gone up 300% to 400% and the value of the neighborhood properties had decreased as a result of negligence.
He said West Haven had implemented some flood gates to mitigate flooding.
Mr. Michel said the ACE had studied the idea of levees in Byram. “When ACE looked at it 5-7 years ago, it was in the hundreds of millions of dollars to do that type of project.”
A Rex Street resident said her home had eight feet of water in the 2021 and couldn’t find flood insurance for less than $8,000.
Mr. Michel repeated the impact of being at the bottom of the watershed.
“Water from Bedford and New Castle (NY) comes down through the watershed. …That’s what the River does as it comes down to the Sound, you get more and more water. By the time you get down to Caroline Pond, there is significant significant flow.”
Mr. Griffasi said he was concerned about development in northern Greenwich and the impacts to Pemberwick. (There is a 456-unit development proposed on American Lane in the northwest corner of Greenwich).
For her part, Ms Roberto again pointed a finger at West Lyon Farm.
“Those ponds illegally held more water than they were supposed to. I feel that Lyon Farm is the cause of all our misery. Sure they’re going to try to show they’re working with you, but I don’t trust them at all.”
Mr. Michel noted that water also comes down from Moshier Street, and was potentially half of the drainage area. Further he reiterated, “It was a significant rainstorm. It was a lot of rain. It was rain we do not see on a regular basis.”
Andrea Blume, leader of the Pemberwick-Glenville Association, agreed that the increase in impervious surface was an issue.
“Now with the development particularly in this neighborhood we’re seeing less green space,” she said, adding that there had been a proposal to develop 777 West Putnam with hundreds of units. while it was withdrawn, she said she believed another proposal would be made to develop the property.
“Impervious surface is a primary focus of DPW in general,” Mr. Michel said, adding that DPW engineers review all developments for compliance with the town’s drainage manual, which he described as more restrictive than most manuals in the state.
“New developments do not increase the amount of runoff as a requirement,” he said.
Mr. Griffasi said people with in Cape Style houses can’t bring the mechanicals upstairs, and their driveways go under their homes.
“I don’t want to have no garage,” one resident said.
“What do you do with a Cape – you can’t put our furnace upstairs in a bedroom, there’s no attic. It was like Niagara Falls,” she said.
Mr. Michel said recommendations are to consider a small addition or adding a second level onto a home to move mechanicals.
“P&Z continues to look at their regulations on these. We have brought it up to them that if people are looking to solve these flooding problems, don’t be an impediment to them,” he added.
FEMA grants exist to help impacted property owners to make their homes and businesses resilient against future floods (e.g., through building elevation) or to purchase their property and relocate to safer locations. To help communities and property owners take advantage of these programs, the Western Connecticut Council of Governments (WestCOG) has launched a Regional Flood Mitigation Assistance Program. WestCOG has retained Dewberry, an engineering firm with decades of experience in disaster recovery, to educate property owners about these opportunities, determine if they qualify, and aid in the preparation and submission applications for floodproofing, buyout, and/or other forms of flood mitigation.