Flood Inundation Maps & Report Released for Lake Champlain & Richelieu River

In the last post, information was provided about the draft report prepared by a working group of the International Joint Commission (IJC) about flood inundation and forecasting in the Lake Champlain-Richelieu River watershed.  The IJC is a a collaboration between the US and Canada to provide coordination, management and protection of shared watersheds. Here in Vermont, we have representatives that have been appointed to the International Lake Champlain-Richelieu River Technical Working Group.

Today, the final report that came out of the Lake Champlain-Richelieu River Technical Working Group was released.  The report, A real-time flood forecasting and flood inundation mapping system for the Lake Champlain-Richelieu River watershed, was an outcome of a 2013 comprehensive Plan of Study.

From the press release:

"The IJC endorses the TWG observation that enhanced coordination among agencies involved in real-time forecasts is necessary to support the development and maintenance of forecast models and quality-controlled joint water level predictions. The Commission endorses the TWG recommendation that a binational coordination body be mandated and funded to consolidate and synthesize flood forecasting work undertaken domestically into a single binational flood forecast. This body would also be charged with developing and disseminating consistent messaging to emergency responders and the public.

"Consequently, the new IJC report does not evaluate potential flood mitigation measures as this was outside the terms of reference provided by governments.

"The Commission reiterates its strong recommendation that governments implement the full scope of the 2013 Plan of Study (PoS) to evaluate past impacts, flood plain management practices and adaptation strategies, and to assess soft (i.e., low impact and cost) to moderate flood mitigation measures and their impacts."

An outcome of the report was a series of inundation flood maps that show the areas of the Lake Champlain and Richelieu River shorelines that would be inundated when the Lake flood waters are at a certain height. Again, from the press release:

"The inundation maps show flooding potential under different flood scenarios and are not designed for regulatory purposes. A preview of these maps is available on the IJC web site at: http://arcg.is/1MhXui2."

Please take some time to explore the inundation maps, as well as read through the final report which can be found at http://ijc.org/files/publications/Lake-Champlain-IJC-Report-to-Govts-Dec-2015-NEW.pdf 

Interactive Flood Inundation Mapper Released for Waterbury

The USGS Flood Inundation Mapper now includes data for Waterbury Village, Vermont.   This web-based map tool allows you to see the extent of upcoming flooding based on flood predictions from the National Weather Service.

This is the first demonstration of the USGS Flood Inundation Mapper in Vermont and it will be particularly helpful in emergency situations.  The National Weather Service already has a NWS Advanced Hydrologic Prediction Service page for Waterbury that predicts how high the river will get (stage) and describes where the water will spread.  The new USGS Flood Inundation Mapper will work together with the NWS page to visually illustrate the buildings, roads and services that will be affected during specific flood events.

Zoom to Waterbury, Vermont and click on the triangle.

USGS has also released an updated study of flood hazards in Waterbury.  This new study uses fresh information about river flows and improved landscape information covering the area north of Main Street.   The FEMA Flood Insurance Rate Map in effect now used flood information up through 1998.

Flood maps for the Winooski River in Waterbury, Vermont, Scott Olson 2014: U.S. Geological Survey Scientific Investigations Report 2015–5077.  

On the Waterbury Flood Inundation Mapper – the extent of flooding at the 429 foot stage just exceeds the USGS calculation for the extent of the one percent annual chance flood.

In April 2015 Waterbury also received an independent study commissioned by the Lake Champlain Basin Program:

Evaluating the Costs and Benefits of Floodplain Protection Activities in Waterbury, Vermont and Willsboro, New York, Lake Champlain Basin, U.S.A.R. Schiff, S. Bighinatti, E. Fitzgerald, N. Wahlund, D. Carlton, A. Church, J. Louisos, and B. Cote, Milone and MacBroom, Inc.; Fitzgerald Environmental Associates; Earth Economics, and DK Carlton and Associates. April 2015.

One page summary: Floodplain Management Economics Fact Sheet, Waterbury, Vermont.

This Lake Champlain Basin Program study looked at mapped flood hazards as well as trends affecting future flooding.  This thorough study was particularly attentive to the costs and benefits for communities like Waterbury to plan and create an affordable flood resilient future.