Convergence Park Proposal

A Plan for New Savannah Bluff Lock and Dam That Works.

A revitalization project that benefits the whole community.

In 2018, the Corps of Engineers announced plans to remove the New Savannah Bluff Lock and Dam and replace it with a rock ramp. The project is to allow endangered fish to reach their historic spawning grounds as required by an agreement that settled certain disputes concerning the Savannah Harbor Deepening. The project has pitted neighbor against neighbor and has become mired in lawsuits. This presentation suggests there is a different path, one that needs to be considered, one that would:

*Maintain the existing pool in Downtown Augusta/ North Augusta;

*Allow migratory fish access to historic spawning grounds;

*Provide a recreational hub and tourism draw for Augusta's River Region;

*Provide an economic stimulus to South Augusta and Augusta as a whole.

By modifying the Corps rock dam, adding a series of gates and a flood channel/ recreation channel, we have designed a solution that meets everyones needs. Use the slider to explore the before and after.

Background

01 / 09

Our Lifeblood

The Savannah River helped build the towns along her banks by serving as a highway, source of food and water, and a choice place to recreate.

The Last Dam

Built in 1931, the New Savannah Bluff Lock and Dam provided a higher pool of water in Augusta for the barge traffic. Commercial barge traffic at this location ended in the 1970s.

A Park for Everyone

The park has long been a meeting place for people from all walks of life within our community. It is the only handicap accessible fishing location along the river in Augusta.

After the Barges

Long after the barge traffic ended, the lock and dam continued to serve as a community bank fishing spot. The dam continues to hold the water higher in downtown Augusta / North Augusta.

Current Conditions

After years of deferred maintenance, the Dam has fallen into disrepair. Not all gates are functional, the inside lock wall is no longer usable, and a large scour hole exists directly downstream of the dam itself.

The Harbor and the Fish

Because of the damages caused by the Savannah Harbor Deepening project, a federal requirement exists that the Corps of Engineers reestablish historic spawning routes.

The Corps Solution

The Corps is proposing to build a rock dam to re-establish the historic spawning route and keep the pool above the dam elevated. This plan is plagued with issues and is currently part of a lawsuit .

Conflict

The Corps proposal has many unresolved issues, and the project has become embroiled in lawsuits. Our team of experts have been working to come up with a solution.

The Solution

We are a team of experts working together to create a proposal that meets all of the needs of the project. By using state of the art technology and the foremost experts in whitewater and sturgeon we have designed a solution where everyone wins.

The Video

River Run Intro Video Savannah River

The Pool

Heart of Two Cities

Augusta, Ga. and North Augusta, SC are located along the banks of the Savannah River, however their portion of the river itself is actually a pool. The water in the pool is about eight feed higher than it would be without the dam below.

The Pool Lowered

The Corps preferred alternative significantly lowered the water level upstream. This issue is compounded by an old Corps wall, an 1800's relic of the old Augusta Port.

114.5' above Sea Level

The desire of those in Augusta's River Region is to see the river level remain on average at 114.5' above sea level. For that reason our design used that level as one of our primary indicators of success.

Obermeyer Crest Gates

Our design is a best-of-both-worlds solution. Using crest gates mounted on the lowest of the Corps rock dam alternatives, the pool level can be maintained without increased flood risks. While at the same time providing the ideal flow through the fish passage for the fish.

Pneumatic Gates

Twenty five 6'x20' Obermeyer pneumatic gates are mounted on the crest of a 108' elevation rock dam. Each gate is independently controlled remotely providing the ultimate control of water levels and velocities. Use of the rock ramp for recreation would only be allowed during times safe for spawning fish.

Our Solution

By adding the flexibility of a series of crest gates on the weir and creating a tiered floodway channel through the park, we have converted a project plagued with issues into a solution that we believe will work for everyone.

The Fish

01 / 06

The River Runners

"Perhaps the most shocking is the loss of 'mega-fishes'- so called because of their enormous size- whose populations have declined by 94% since 1970, including many species of now- critically endangered sturgeon." - National Geographic

The Endangered Dinosaur

The Savannah River is home to two kinds of critically endangered sturgeon. The Atlantic and the Shortnose Sturgeon are some of the oldest animals in existence dating back over 40 million years.

Our Fishing Heritage

People have lived along the banks of the Savannah River for more than 10,000 years. Until recent years, the river has provided a ready and abundant population of fish. However, with industrial pollution, dams, and boat strikes our native populations have plummeted to dangerous levels.

Fish Passage Reconnect Fish Highways

Up to 80% of freshwater fish migrate in a river system. When the river is reconnected, not just the sturgeon benefit, all of the fish do. This design incorporates notches and resting pools making passage upstream and back down safer than the current Corp proposed design.

Optimal Flows

Shortnose Sturgeon can only migrate upstream if the flow through the passage is around 1m/sec. Because each of the pneumatic gates are independently controlled , this flow can be maintained.

Flood/recreational channel is fish safe

The floodway terminates at Butler Creek and incorporates various techniques to discourage sturgeon from entering the channel. If a fish does get into the channel, the design includes pathways around rapids features to make its way upstream. These bypasses also serve as wading pools for people wanting to enjoy the water without a boat.

The Park

01 / 06

Building a Park for the Future

This historical park has been neglected far too long. With the construction of the fish passage comes an opportunity to revitalize the park in ways the community and visitors will love.

Historically Important

The existing park has long been a hub of activity in Augusta. By installing ADA compliant docks and bank fishing access points, we are expanding the current amenities. Our vision enhances and celebrates current users.

A Park for Everyone

The park is designed with everyone in mind. The semi- circle is a wading pool built so those not wanting to tube or kayak can still enjoy the water safely. The park amenities are ADA compliant and easy to access.

Recreational Attraction

By creating a floodway channel with through the park and outfitting it with adjustable gates, the park will become a major attraction for tourists and Augustans alike. The flexibility of the gates means the course can go from a tubing adventure to a competition canoe/kayak course with the touch of a few buttons.

Pool Recreation

With ADA compliant docks and an improved boat ramp, this park will provide even more access to the river than is currently possible. Whether you have a boat or not, you will be able to enjoy the river and all it has to offer.

More than just a River

The park will provide opportunities for small businesses to run amenities like a zip line, food trucks, disc golf course, tubing operations and a bait shop. These amenities will be determined as the project progresses.

Who We Are

Bill is a senior attorney at the Southern Environmental Law Center. After graduating from Harvard Law School in 1990, he served four years in the Army as an attorney with the Corps’ Chief Counsel’s office in Washington, DC. Bill later practiced at Alston & Bird’s Atlanta office for six years before becoming lead wetlands attorney for Region 4 of the U.S. EPA.

Dr. Boyd Kynard served as our Sturgeon expert. He has a PhD in Fishing and Fisheries Sciences and Management and has conducted field and laboratory stream research on migratory fish in rivers on three continents over his extensive career. Boyd is one of only four fish passage experts to be given a lifetime achievement award from the International Conference on Engineering and Fish Passage in 2012. Boyd was part of the BECTEL team that reviewed the Corps preferred alternative.

Dr. Brian Wellington of Newfields Engineering developed and ran the engineering model demonstrating the efficacy of the design. Brian is a seasoned project engineer with expertise that includes hydrologic modeling, water quality modeling, and erosion and sediment control design. He earned an M.S. in Water Resources Engineering and a Ph.D. in Civil and Environmental Engineering from Syracuse University.

Tonya Bonitatibus, Savannah Riverkeeper, is constantly looking for ways to get people out on and in the river. She is discussing the importance of this project for the river and the community as a whole. Tonya has long been an outspoken proponent of the whitewater project at the lock and dam park.

Cost / Benefit

Dan Gilbert

The owner of Whitewater Express discusses the benefits of whitewater in Columbus, Ga. In 2019, more than 50,000 people traveled from over one hour away or more to visit the river.

Richard Bishop

Former Uptown Columbus director discusses the benefits of a similar restoration project has had on Columbus, Ga. Since 2014, gross reciepts are up over 50%.

Technical Info

01 / 06

What are Crest Gates

Crest Gates are pneumatic gates that use clean air to operate. The Obermeyer gates are used throughout the world to regulate water flow.

Economical and Better

The Obermeyer gates are mounted on the crest of the rock weir at 108' above sea level. The 25 gates across the river cost under $4 million making this proposal cheaper than the Corps' current alternative.

Federal vs. Local Dollars

The weir, in-river crest gates, and flood channel are all components of the federal mitigation project and should be paid for by the project. Local interests would pay for the recreational gates in the floodway and other desired amenities.

Long Term Maintenance

The crest gates have a 50-year lifecycle, and replacing them is simple and economical. Thus, the cost of maintaining the crest gates will be far less than maintaining the current dam.

Who Regulates Flow?

Through releases at the J. Strom Thurmond Dam , the Corps of Engineers would continue to regulate river flow. The City of Augusta would be able to regulate the water passing through the floodway channel.

Where are they located?

Recreational Locations:

Charlotte, North Carolina

Bend, Oregon

Boise, Idaho

Denver, Colorado

Vail, Colorado

McHenry, Maryland

Holtwood, Pennsylvania

Hydrology/Hydraulic Modeling

*Site was modeled as a 1-D steady state model in HEC-RAS

*Model was developed by converting the US Army Corp’s 2-D unsteady state model for the site.

*Conversion included:

Removing 2D Flow Grids

Modifying terrain in proposed location of weir

Adding Analysis Cross sections

Modeling Objectives

*Maintain Water Surface Elevation at 114ft at City of Augusta (5 St Bridge)

*Ensure that flow velocities through proposed weir gates are maintained at levels that will not impact fish migration <= 4.5 ft/sec

Model Inputs

Weir Elevation – 108 ft

Number of Obermeyer Gates -25

Fishway Rock Arc Length – 30ft

Fishway Slot Length - 10 ft

Model Scenarios

*Three Flow scenarios were modeled

*High Flow Conditions (January to April)10,500cfs

*Moderate/Average Flow Conditions (March to May) 8,500cfs

*Drought Flow Conditions 3,500cfs

At higher flows about 10,000 cfs all of the river crest gates would be folded down completely. Flooding flows would be accommodated by folding down gates in the bypass/whitewater channel as well.

At average flow of 8500 cfs 7 of the 20' wide gates would be folded down on the Georgia side.

During times of drought at 3500 cfs 4 gates would be open on the Georgia side allowing fish to still pass in the fish passage.

Explore

A flythrough video of the Convergence Park rendering.

Q&A

Q. Can Obermeyer gates hold water level in Augusta safely at 114.5? Current gates have bottom outlet gates, I heard they work better, is that true?

A. Yes, the gates can safely hold the water level in Augusta. No, the bottom outlet gates do not work better. The proposed gates are superior to the bottom outlet gates for regulating upstream level because the discharge from crest gates increases to the 1.5 power as the upstream water level rises, without invoking any automatic control or passive compression of air in the bladders. The gates are automated to sense gate position and calculate flow rate allowing for the control mode to be selected based on upstream level, spillway discharge, or other parameters as required. The discharge from bottom outlet gates varies in proportion to the .5 power of the upstream elevation. Much larger and frequent adjustments of a bottom discharge gate are thus required in order to regulate upstream level.

Q. What happens if one of the air bladders fail, will the river drain?

A. No, the river will not drain. There are 20 independently controlled gates built across a weir set at 108' elevation. Under normal operations a majority of the gates would be folded down. If 1 gate failed the operations system would compensate to retain upstream elevation through manipulation of remaining gates until repairs can be made. This system has been used on high hazard dams throughout the world safely for many years.

Q. Can the fish swim over the gates?

A. Yes, a folded crest gate does not create an impediment to fish passage and in fact when the gates are used together, the ideal flow rate for sturgeon and other anadromous fish can be achieve as a wide variety of flows. This builds resiliency into the project.