Southeastern Connecticut is bracing for a day of heavy rain expected to pound the region starting this afternoon, bringing an estimated 3 to 5 inches of rain, including stretches when 1 to 2 inches of rain per hour could fall, the National Weather Service said in a briefing Wednesday.
Rain is expected to become heavy starting about 2 p.m. today and running through Friday morning, with steady rain ending Friday afternoon. The National Weather Service has issued a flood watch for all of New London County from 8 a.m. today through 8 a.m. Saturday.
Winds of 20 to 30 mph are expected along the coast, with gusts of 40 to 50 mph. Inland winds are expected to range from 15 to 25 mph, with gusts of 30 to 40 mph.
Norwich Emergency Management Director Gene Arters said the system is similar to the March 2010 storms that caused major flooding throughout the region, as a major storm followed several soaking rain storms.
The Yantic River in Norwich is prone to flooding in several heavily developed areas, including Norwichtown and Yantic. In 2010, several feeder streams into the Yantic also flooded in low-lying residential areas.
Arters urged all residents in flood-prone areas to prepare for the storm and recommended all residents prepare their basements for potential flooding by removing valuables and securing appliances.
Flood stage in the Yantic River is 9 feet. The National Weather Service projected the worse-case scenario showing the river reaching up to 12 to 14 feet in the overnight hours tonight into Friday morning. Moderate flooding occurs at 11 feet.
Arters said officials at the newly renovated Norwichtown Commons are preparing to install the shopping plaza's flood gates.
In 2010, the Nutmeg Companies at 31 New London Turnpike, located on a low-lying river bank property near the shopping plaza, set up a floodwater wall with concrete blocks and sandbags along the river bank. But the property was deluged when a wall of water crashed through the rear wall of a storage building that had been part of the flood wall.
Nutmeg co-owner Evert Gawendo said Wednesday that the storage building wall has been reinforced, and the company already moved flood blocks into place along the river for last Friday's heavy rain. He is confident the flood wall will hold.
The Yantic was at 4 feet Wednesday afternoon behind Nutmeg. Last Friday, the 4½ inches of rain raised it to 8 feet. Gawendo said the Nutmeg property floods at 12 feet, but the river could rise fast with the ground already saturated — as happened in 2010.
Groton Emergency Management Director Joseph Sastre said the anticipated conditions create the possibility of flooding on low-lying roads and in basements and of overflowing rivers.
"I think there's a good possibility (of flooding) simply because the ground is already saturated with all the rain we have had in the past week," he said. "I don't think the ground is going to be able to absorb more."
Small brooks, such as Whitford Brook in Old Mystic, are already at higher water levels than normal due to last week's rain, he said.
The anticipated conditions are similar to the ones experienced in March 2010, Sastre said. While he said it would not necessarily reach that level of flooding, he was "concerned because the precursors are there."
Anticipated wind gusts add a second concern: the potential for utility outages.
"When you have windy conditions and sopping wet grounds, trees and telephone poles tend to fall over," Sastre said.
The department of emergency services is aware of the situation, and the dispatch center will be staffed this afternoon and evening.
In East Lyme, Emergency Management Director Richard Morris said the town is monitoring the situation and will react to the conditions as necessary.
"We're always preparing," he said. "We're always making people aware of what's going on and posting updates of the weather changes through Facebook."
Ocean Avenue experienced some flooding last weekend due to Friday night's downpour as well as from waves from Niantic Bay. The potential for flooding, especially in low-lying areas, depends much on the tide and when it starts raining, Morris said.
However, in terms of the town's lakes, he said the spring runoff has already occurred for the most part and the lakes are not overfilled with water.