Mill River to Mother Nature: "It's your turn, now."

12/11/12 - Today marked completion of human-led work at the Hopewell Mills Dam site, and the start of Mother Nature's lead role. 

 Photo 1: Mill River looking upstream through the former spillway site. Contractors installed tree trunks as bird perches on the floodplain.


Contractors planted the site last week with native trees and shrubs.  Hydroseeding took place today (that's the bright green you see in the photos).  Next week I'll add a few before - during - after photo sequences.  After that, the blog will take a break until the Whittenton Dam Removal Project begins upstream in few months.
   

 Photo 2&3: These pictures look downstream towards the former spillway.  In the photo above, logs and rootwads installed as habitat poke out of the stream bank.

 

 

Photo 4: This picture looks upstream from the former dam, across the impoundment, towards the Reed & Barton mill (brick buildings and smoke stack associated with the mill are in the distance).  The weird green color comes from the hydroseeding.

The last scoop

November 27, 2012 -- Today, RC&D removed the last scoop of sediment from the former mill pond.  The floodplain of the river is now revealed. 

 

Unlike what you might expect, the floodplain is not flat -- instead, it has gently sweeping highs and lows.  The engineers had included highs and lows in the design plans (referred to as "microtopography").  In the end, it was not necessary to build in the microtopography; it was already present in the natural contours.

 
Over the next week, landscapers will be planting the floodplain with native trees and shrubs, tailoring the location of the plants to the topography.  Plants that prefer wetter conditions will cluster in the low spots.  Those that thrive in slightly dryer conditions will sit on the gentle rises.  Next spring, as plants bloom or leaf out, this topographic variation will lead to a colorful mosaic.

What do the neighbors think?

The Mill River is lucky to have the Machado family watching out for it.  From their lawn at the upstream end of the former mill pond, the Machados have had a front-seat view of the dam removal project.  Every day, rain, shine, or hurricane, the Machados are outside watching the construction action.  They are familiar with every detail of the construction work.  On weekends, when the construction crews are at home, the Machados relocate fish and turtles from the construction site to nearby rivers and ponds. 

"This project is a dream come true," says Mr. Machado.  "I never thought I would see it happen in my lifetime".  He and his family enjoyed watching the swans, geese, ducks, and turtles that lived in the impoundment.  Now they are excited to see herring, kingfishers, ducks, herons, and eel return to the river in the spring.  We fully expect that the turtles will be back, too.

Here's the view from the Machado's lawn last week.  The dam site is too far in the distance to see; you are looking downstream towards it.  The Mill River is in its new channel and is almost bankfull in response to Hurricane Sandy.

Here's the same view a month ago:

And here's the site looking upstream from the former dam towards the Machado's house:

Mill River channel restoration completed

Other than touch-up work, stream channel restoration is done.  I took this picture from the middle of the impoundment looking downstream towards the former dam.  At the upper right hand corner of the photo is a bare slope.  This is where the Hopewell Mills Dam sat.  It extended from that bare slope all the way to the right edge of the photo.
 

I took this photo from the downstream end of the impoundment; it's the last meander bend before the river reaches the former dam site.  The engineering plans included pools, point bars, and gravel deposits, all of which can be seen in this photo.

 I took this picture from the middle of the impoundment looking upstream.  The brick Reed & Barton silver mill is in the distance.  Now that the channel construction is done, the crews will continue removing contaminated sediment from the floodplain and plant the floodplain with native trees and shrubs.

A Celebration of the Mill River

On Friday, October 19th, project partners, friends and local officials gathered to celebrate the Mill River, the removal of the Hopewell Mills Dam, and the future of the restored river. Tim Watts gave a fitting tribute to the past and future of this beautiful river, and reminded us of why we were all gathered together. The Wild & Scenic Stewardship Council presented Barney Frank with a National Park Service Wild & Scenic River sign to thank him for his dedication to the Taunton River and local communities. Officials from all of the participating agencies, as well as local legislators and the mayor of Taunton spoke about what the project means for the community.

Special thanks was given to our partners at the Department of Mental Health who have gone above and beyond to see the Hopewell Mills project completed. Special recognition was also given to the Reed and Barton CEO and CFO who have pledged to support the final phase of the project, removal of the West Brittania dam, located on their property.

A tour of the Hopewell Mills project was provided by Nick Nelson from Interfluve, and participants were able to see the newly constructed stream banks, pools, riffles and large woody habitat that will form the structure of the stream. Here are links to media coverage in South Coast Today and the Taunton Gazette.

Channel construction continues

The banks of the Mill River are taking shape as meander bends are constructed using coconut fiber soil lifts. These banks will provide structure to the channel until plants take hold. The bottom layer will become part of the channel bottom with gravel and cobbles, and the top two layers will degrade over time as plants grow.

Large wood and root wads from the trees that were once on the dam will later be placed in the channel to add habitat structure and a place for fish to hide and turtles to bask. The floodplain surrounding the channel will be a lower elevation and will be able to store floodwater at high flows.

The Mill River channel takes shape

Last week, construction crews finished roughing in the Mill River channel through the former impoundment.  The new channel has a gentle slope and meanders across the new floodplain.  The photo above gives a sense of the curves; this photo was taken from the mid-point of the impoundment looking downstream.  This week crews will begin constructing the stream banks by building burritos of soil.  Crews will also place gravel in the bed of the stream.
 

 

Meanwhile, the impoundment continues to green-up with pioneer wetland species and grasses.  "This looks better than my lawn," said one visitor.

The photo above was taken at the former dam looking upstream.  Again, you can get a sense of the sinuosity of the new channel as it winds off to the left.

Of riffles and muck

September 21, 2012 - With the diversion channel finally in place, RC&D began removing sediment from the impoundment this week.  Sediment was trapped by the dam over hundreds of years.  It is stratified into two layers: a surficial layer of silt (muck) and a layer of sand.  Beneath the sand is the historic floodplain of the Mill River.  Crews are removing the silt layer and placing it in an upland reuse area nearby.

Also this week, crews began building a riffle where the Mill River enters the (former) impoundment.  Above is a picture of the excavator as it builds the riffle.  Below is a short video clip.

Finally, crews graded the channel for the Mill River at the downstream end of the project area.  Eventually, the crews will construct a riffle here and build river banks.  I took this picture standing at the upstream end of where the spillway of the dam used to be.

Dewatering and Diversion Continue

Work on diverting the Mill River through a new temporary channel is continuing today. This lined channel will carry the river while a new channel is constructed through the impoundment. This is when the exciting work of river restoration begins - creating meander bends, channel banks and woody habitat.

Remnants of the old mill were still visible last week. The crew was unable to break apart these larger sections of the old mill walls which have stood the test of time and machinery. A report on the industrial archaeology of the mill will be completed at the end of the project, and we will use the information to create interpretive signage at the site.

Changing Habitat in the (Former) Impoundment

8/28/12 - This week, the contractor is constructing a diversion channel around the Hopewell Mills Dam impoundment.  While the water was drawn down almost three weeks ago, the sediment is still wet and mucky. The diversion will help dry out the sediment so that heavy equipment can excavate the new channel and shape the floodplain.

The wet sediment, meanwhile, hosts migratory shorebirds as they head south.  Birdwatchers have seen Killdeer (Charadrius vociferus) and Least Sandpipers (Calidris minutilla).  Both species feed on insects found in mudflats, so it's not surprising that they are flocking to the impoundment.  The photo abov shows 1) the new channel of the Mill River towards the upstream end of the impoundment; and 2) the mudflat habitat that is popular with the shorebirds.  The mudflat condition is only temporary; at the end of the project, the Mill River will meander through a meadow planted with native trees and shrubs. 

 

It is exciting to watch the site change.  Compare the photo above, taken 8/28/12, with the one below, taken from the same point three weeks ago.

The first riffle in 200 years

August 23, 2012 - The Mill River flows freely through the former Hopewell Mills Dam spillway site for the first time in 200 years.  Like all free-flowing rivers, the Mill River now has the power to move bed material and build habitat.  We humans frequently engineer and construct habitat features like pools and riffles.  Yet, rivers have been doing that work without our help for eons.  Within a week of fully removing the spillway of the old dam, this riffle developed.  Note the slight turbulence caused by the cobbles and small boulders -- riffles aerate the river water.  Riffles are also "kitchens" where stream insects live and fish feed.  Contractors still have a lot of work to do to excavate contaminated sediment and shape the new stream channel.  But, this naturally-formed riffle reminds us that once the construction crews leave the site, Mother Nature and the river will take it from there.

In this picture, taken the same day, construction crews install dwatering pipes through the earthen berm dam.  While the spillway of the dam is gone, thousands of yards of material still fill the old floodplain.  This artificial fill will be removed so that the Mill River can regain floodplain habitat and function.

And The Walls Came Down

Today's work included more removal of the earthen dam, and chipping away at the walls. After much hammering, the walls came down. Water levels are up, due to recent rain (downpours), so a diversion channel will be constructed through the eastern side of the dam to further drain the impoundment. By next week, much of the recognizable dam will be gone!

Millions of Herring

Brian Graber (American Rivers) and Rachel Calabro (Save the Bay) discuss the Hopewell Mills Dam removal and the Mill River Restoration.

Chipping Away At the Spillway

Beth Lambert from the MA Division of Ecological Restoration passed along this photo this morning of the construction crew starting to break apart the Hopewell Mill Dam's spillway. While removing the dam includes months of construction work, the spillway removal is the classic dam removal moment!

A River Returns

Today, the impoundment continues to drain, and the old channel is beginning to appear. Project partners spent the day meeting with media and documenting the progress. Mary Griffin, Commissioner of the Massachusetts Department of Fish and Game was on site to speak with reporters. Yesterday, Save The Bay was on hand to speak with Channel 12 in Providence. An industrial archaeologist was on site today to document parts of the old Hopewell Mill that can be seen in the earthen embankment of the dam. This photo shows what was once one of the interior walls of the mill.

The First Scoop

The impoundment has been drained by allowing water to flow through the old dam gates. Water now flows under the dam, and the spillway is dry. Excavation of sediment behind the dam is beginning and the spillway will be lowered slowly as the impounded sediments dry.

Work begins at Hopewell Mills

Work has begun at Hopewell Mills, and lowering of the spillway will start this week. Trees have been cleared from the top of the dam, roots and all. These trees with their root wads will be reserved and used in the former impoundment to give structure to the new stream channel and provide habitat and bank stability. The construction crew will be lowering the impoundment by moving gates that exist in the old dam, releasing water downstream. When water levels drop, the concrete spillway will be lowered using a hydraulic hammer. This part of the work will most likely begin on Thursday.

Work is ready to begin!

Permits have been received and our contractor, RC&D, is ready to start work next week. Mobilization and site preparation will begin on Tuesday, July 24th. Check back often for photos and notes from the field!

Hopewell Mills Dam Removal

The first major project in the Mill River Restoration will be the removal of this dam at the Taunton State Hospital. Final permitting is under way, and work will begin this summer.