08/27/11 Greenwich Roundup Reports ....

YOU WONT READ THIS IN THE GREENWICH TIME:

Town Resident Warns Of Even More Greenwich Streets That Are In Danger Of Flooding

Michael Finkbeiner: "The selectmen should base the street list on the FEMA FIRM maps, which are for the National Flood Insurance Program."

Where are the Pemberwick streets?

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The Above SLOSH model looks like an evacuation zone map for Pemberwick, but Mr. Finkbiener says it is not.

However the FEMA Flood Insurance Rate Map Firmette clip for a small section of the Byram River, should be compared to the SLOSH Map used by the Town of Greenwich according to Mr. Finkbiener.

In a CATAGORY 1 Hurricane, which Irene may not be at Connecticut landfall, only the lime green zone is indicated for impact.

In Pemberwick, this would only be Den Lane and River St, since rainfall is not included.

Once rainfall is added as a hazard, a very different picture emerges.

There is a FEMA CLIP and mention Mr. Finkbriener's FEMA FIRMette collection on-line at http://bit.ly/n1byb3.

The corresponding FEMA clip for Pemberwick is at http://bit.ly/qTBood

In an email interview Mr, Finkbiener told Greenwich Roundup ....

"The SLOSH map is mis-leading, since many residents may read the map as an evacuation zone map, which it is not, and conclude they are safe because they are in zone 2 or 3, which don't apply to this storm's slosh.

This is false, they are at risk due to river and stream urban flooding - not tidal storm surge.

For the purposes of the Pemberwick - Glenville area, the only Pemberwick streets on the list are there due to tidal flooding, which is not the primary risk.

And for the same reason, no Glenville streets are included, although many are at high risk right now!

Therefore, I urge the Pemberwick - Glenville Association and the Greenwich Emergency Management office to reformulate warnings and evacuations, based on the FEMA Flood hazard, which includes tidal, but more importantly, river and stream flooding due to excessive rainfall and intensity, which will be the killers in this storm event.

Again, to explain - SLOSH is the wind and tide risk without rainfall. FEMA FIRM is the combined flood risk based on hydrology, hydraulics of piping infrastructure, and the interaction between tides, storm surge and rainfall runoff."

From: Michael Finkbeiner [mailto:mwfinkbeiner@gmail.com]
Sent: Friday, August 26, 2011 11:28 PM
To: VAD5573@aol.com; Peter Tesei; drew.marzullo@greenwichct.org; David N Theis
Subject: Re: Latest Town Hurricance Alert

The Town's Evacuation program appears to be based on the SLOSH Category I list only, not the FEMA Flood Insurance Risk mapping that is the basis of the Flood Hazard Overlay Regulations of the Town, Sec 6-139.

The Street list and SLOSH maps used by the Selectmen represent wind driven tidal flooding by salt water only, and ignore the rainfall, runoff, and urban flooding hazard of the rain component of the storm.

Pemberwick Streets are not included for this reason. Neither are the other non-shoreline flood prone areas included. The Byram, Mianus, and Horseneck Brook watershed flooding components are ignored.

However, IRENE is likely to be remembered for its rain and flooding components as the primary hazards.

The Town's Emergency Management Response should rely on the FEMA Maps of June 18, 2010 to assess flood risk and hazard.

I testified to this effect on June 1, 2010 at the P&Z hearing for the revised Flood Hazard Overlay Regulations.

Michael Finkbeiner, LS

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Mr. Finkbeiner seems to be saying that ....

It is important to understand that the SLOSH model is only for storm surge, not rain or fresh water flooding.

The Town appears not looking at the flood impact of rain in this analysis.

One must add the sea water run-up in the SLOSH model to the rivers and streams carry local flood waters into Pemberwick.

The SLOSH plus high-tide makes this a very serious event for everyone flooded in 2007.

UPDATE:

Michael Finkbreiner Added These Comments To This Report:

I mis-spoke about Pemberwick Streets - most of them are on the Selectman's Notice of 8/26 6:15 pm. but on the map they are for hurricane Cat 2 & 3. Add Cat four, and you have a map similar to the FEMA FIRM for Pemberwick.

But the Glenville streets and all the other flood prone streets subject to river and stream flooding, but not tidal storm surge, are missing.

The reason is that the SLOSH model is for the purpose of separating the rising tide risk from the river flooding risk coming from upstream watershed areas. This is necessary in writing an evacuation plan for different types of storm events.

Thus the Selectmen, and specifically by identified parties of Mr. Warzoha and Ms. Baisley in their Press Release, representing Emergency Management and Dept of Health, have mis-led the public by mis-use of the SLOSH Model map document, and lack of a rainfall-flooding evacuation plan.

This may prove to be a life threatening error.

If Irene arrives as a tropical storm event, the SLOSH wave-energy run-up models are of NO relevance.

What is needed is focus on the lack of infrastructure repairs, and urban hydrology appropriate to coverage conditions of land use in Greenwich.