Mad River Bank Stabilization Project

Background

The project area is located in Waitsfield's historic Village, which is listed on the Federal Register of Historic Places.  It is also a Designated Village Center through the Vermont Downtown Program.  It consists of a number of historic structures built in very close proximity to the Mad River, a covered bridge over the Mad River, and a municipal building that serves as the town offices and library. The Waitsfield Covered Bridge is the oldest operating covered bridge in Vermont. The Village serves as a regional hub for multiple uses, including civic, retail, restaurants, condominiums, homes, other businesses, and even agriculture.  Waitsfield is located in the heart of the 143 sq mile Mad River watershed, which drains in a northerly direction into the Winooski River and ultimately into Lake Champlain.

In May of 2010, the town of Waitsfield took proactive steps to protect the stream corridor by adopting both a fluvial erosion hazard (FEH) ordinance and an enhanced flood hazard ordinance using the FEH maps produced from geomorphic assessments.  This effort was identified as a top priority in both the 2008 Upper Mad River Corridor Plan and the 2007 Fluvial Geomorphic Assessment of the Mad River Watershed report. Waitsfield recognized that protecting floodplain and river corridor function provides flood storage, mitigates flood hazards and enhances water quality.  Mapping support from the Central Vermont Regional Planning Commission was possible due to a prior PDMC Planning Grant.

Goals and Objectives

The primary goal of this project is flood mitigation, designed to reduce or eliminate risk to people and property from flood-related erosion hazards and their impacts.   Implementation of this project would significantly reduce acute flood-related erosion risk to an historic village area and would protect the Waitsfield Town Office, marketplace area, and a well-traversed road that connects several rural communities.   The Town was able to determine where the hazards are of greatest concern and identified specific measures needed to reduce the severity of existing hazards; this project accomplishes these objectives.   These mitigation objectives include avoiding flood damage from bank erosion and bank retreat and channel avulsion through the Historic District, which could damage the bridge abutment of the Covered Bridge.   The project seeks to stabilize approximately 425 linear feet of the eroding bank upstream of the Covered Bridge by reinforcing and riprapping the eroding bank and installing a riparian buffer.   The project combines flood mitigation and river corridor protection.   Additionally, the Town's effort to protect existing floodplain upstream and downstream and this project, in conjunction with this project, addresses both flood related inundation and erosion hazards.   The project will also control sediment loading and help to restore riparian vegetation.The methodology involves the installation of a bulk toe rock revetment, riprap emplacement and buffer along the actively eroding stream bank.   The upstream limit of work is the old dam site, and the downstream limit is the Covered Bridge abutment.  The project is expected to stabilize the eroding bank upstream of the Covered Bridge and include the installation riparian vegetation.

Description of Need

The Bridge Street Marketplace area has suffered chronic flood losses in the recent past. In fact, this area has been affected by severe flooding on at least six occasions since 1927.  The northwestern streambank of the Mad River, just upstream of the Covered Bridge and immediately adjacent to the historic Village, was actively eroding, resulting in bank retreat and heightening the risk of channel avulsion.  The flood of August 28, 2011, also known as Tropical Storm Irene, caused more damage to this streambank, weakening the ground underneath and adjacent to the first line of historic buildings.  Prior to that, a severe rainstorm in October 2010 caused considerable erosion of that bank.   Severe flooding in 1998 caused losses exceeding several hundred thousand dollars.  This included severe flood damage to the Waitsfield Town Office (2 feet of water in the lower level), flooding of several retail stores, and damage to a vital road connecting several rural communities.

The State River Management Program of the Agency of Natural Resources has been monitoring the bank soil erosion for the past ten years.  Based on comparing ortho-rectified aerial photos and topographic maps, the streambank has been eroding laterally toward the Waitsfield Village at a rate of approximately 2 feet per year.   The rate and post-Irene location of the bank has heightened the risk of significant damages to the Village and Covered Bridge when the next large flood event occurs.   The August 2011 flood event heightened the risk of channel avulsion through the Historic Village and around the Covered Bridge.

Grant Funding

Waitsfield applied for and received a grant through the Hazard Mitigation Grant Program (HMGP) from the Federal Emergency Management Agency (FEMA) to implement this flood mitigation project.  Grant funds through the Vermont Dept. of Environmental Conservation Ecosystem Restoration Program supported the initial survey work and studies necessary to complete the FEMA HMGP grant application.  The Ecosystem Restoration Grant Program also contributed 100% of the initial 25% match required State of Vermont also contributed a significant proportion of the cost share, reflecting Waitsfield's commitment to: (a) protect river corridors and floodplains from future development through the passage of strict local flood hazard bylaws, and (b) partner with Vermont Dept. of Environmental Protection and FEMA to protect the businesses, historic buildings, road, Town offices located on Bridge Street and Covered Bridge.

Contract Award

Three bids were received: Kingsbury Companies, LLC (Waitsfield, VT) - $145,555.00; S.D. Ireland (Williston, VT) - $209,900.00; and Markowski Excavating, Inc. (Florence, VT) - $241,803.59.   The Waitsfield Selectboard voted to award the contract to the low bidder, Kingsbury Companies, LLC, subject to the receipt of additional funding.  We received word on August 19, 2013 that an additional $13,627 had been awarded by FEMA through the HMGP program.