This document summarizes a dredging and disposal project at John Redmond Reservoir in Kansas that took place from 2015 to 2017. Over 3 million cubic yards of sediment were removed from the reservoir and placed into confined disposal facilities. The project involved permitting and environmental reviews, construction of the disposal sites, dredging operations using a large electric dredge, and ongoing reclamation efforts to return the disposal sites to agricultural use. The $20 million project was financed through state bonds and water resources funds to help address declining storage capacity in the reservoir due to sedimentation.
7. • 33 U.S.C. Section 408
– RoD Authorized KWO to conduct project on federal property
– Programmatic Environmental Impact Statement (PEIS)
• Section 106 Programmatic Agreement
– USACE Tulsa District, KSHS & Osage Nation of Oklahoma
– Ensure any historic sites were identified/protected
• Section 404 Permit (USACE) & Stream Obstruction Permit (DWR)
– Slurry pipeline crossing of Neosho River
• Dam Safety Permits KDA-DWR
– Required for all CDFs (based on DWR dam criteria)
• Floodplain Fill Permits (DWR)
– CDFs B and F (SFHA Zone A)
• Water Term Permit (DWR)
– Authorized use of water from Redmond for dredging purposes (> 6 months)
• NOI for Stormwater Runoff from Construction Activities (KDHE)
• NPDES Permit (KDHE)
– Effluent Limits at point of discharge
PROJECT PERMITTING
8. PHASE I IMPLEMENTATION TIMELINE
• 2012 - Planning process begins with USACE
• May 2015 – Section 408 Request Final RoD and
FONSI on Programmatic EIS Issued.
• November 2015 – June 2016: Confined Disposal
Facility (CDF) construction takes place
• May 2016: Dredging operations begin
• October 2016: Dredging operations complete
• October 2016: CDF dewatering efforts begin
• 2017 to current: CDF reclamation
21. CDF DEWATERING AND RECLAMATION
Continue Work with Great Lakes Dredge & Dock on CDF
Reclamation
• CDF dewatering has progressed since October 2016
• June 2017, treated water no longer being released to Neosho
River
• CDF F first in line to be put back into cropland production
– All dredged material stays on site, CDF walls will be removed and dirt
work will be completed to establish surface drainage network as well as
re-slope perimeter to stabilize.
24. PROJECT SUMMARY
• 3,000,000 CY of sediment removed (~1,900 AF)
– Average: ~19,000 CY/day
– Max: ~32,000 CY/day
• $20 million ~ $6.67/CY
– Total cost includes permitting, engineering & design, construction,
dredging, lease payments and land reclamation
– Includes some funds for watershed practices above reservoir
• Project financed by 15-year Bond
– State Water Plan Funds
– Water Sales Revenue through Water Marketing Program
To get the presentation going let’s first look at the question of Why Dredge Redmond? That’s a question we get asked frequently, so I’d like to give some background as to what the situation was with John Redmond Reservoir that made it a candidate for a large-scale dredging project.
As many of you know, our reservoirs are in a battle with nature. While artificial, constructed lakes or reservoirs are efficient at trapping and holding water, they are also efficient at trapping sediment. This chart shows some of the federal reservoirs within Kansas and the estimated percent of capacity lost to sedimentation. As you can see from this graphic, reservoirs such as John Redmond, Tuttle Creek and Toronto have lost around 40 percent or more of their conservation pool capacity.
The fact that we are losing storage to sedimentation is not surprising. Sedimentation rates are part of the engineering design plans for these reservoirs. What is surprising is that many of these reservoirs are silting in at a higher rate than anticipated. In the case of John Redmond, the current estimated sedimentation rate is over 1.5 times that of the design sedimentation rate.
Losing reservoir storage capacity impacts the ability to deliver raw water to meet downstream water use needs. This graph shows supply and demand projections for the Neosho River Basin served by John Redmond Reservoir.
The red line shows available supply if no action were to be taken and Redmond continued to silt in at it’s current sedimentation rate, the blue line represents current customer demand within the Neosho River Basin from Redmond on downstream, and the green line shows supply factoring in a 2’ pool rise, Phase I dredging operations at Redmond, as well as streambank stabilization projects above Redmond to help reduce the amount of sediment entering the lake.
For those of you not aware of this, a reallocation request was initiated by the Kansas Water Office in 1996 and was authorized by the Corps of Engineers in 2013 which allowed for 2’ of flood storage to be converted into water supply storage. This reallocation increased the state’s water supply storage capacity within Redmond by a little more than 17,000 acre-feet.
As you can see, the green line still dips below the current customer demand for the basin as we approach the 2030’s and before the year 2045. This 2045 date is significant in that Wolf Creek Nuclear power plant, which draws water from releases made from Redmond and pumps this water to their cooling lake, has an operating license which goes through 2045. This illustrates the need to do additional sediment removal work within Redmond to increase available water supply storage, helping to ensure available supply meets current customer demand, including the demand of Wolf Creek Nuclear power plant, through at least the year 2045.
2012 – extended dry period; full in May, at 30% capacity in Nov. of that same year
Looking closer at Redmond, bathymetric surveys can be used to view and quantify the amount of sediment across the entire lake bottom to determine the amount of water supply storage lost to sedimentation. Comparison of lake bottom elevation data from 1957 to the bathymetric survey conducted in 2007 shows a good portion of the lake experiencing over 1’ of sediment deposition, with areas closest to the dam near the outlet and along the Neosho River channel through the reservoir seeing 10-25’ of deposition.
The dredging project itself is on both federal and private property. The Kansas Water Office has real estate agreements in place for the dredging zone on Redmond, the pipeline route across federal property, the staging area which shows up in orange at Damsite Park, as well as use of land in association with CDF B. All other disposal sites are on private property, and the Kansas Water Office entered into lease agreements for use of this property.
From the dredge zone on Redmond, dredged material was pumped around the north side of the dam embankment, then south across the Neosho River towards the disposal sites downstream of the dam. Dredged material placed within the CDFs then was routed back through the CDFs, with gravity-treated effluent water being discharged back to the Neosho River out of CDF B. This discharge is permitted with an NPDES permit obtained by the Kansas Water Office through the Kansas Department of Health and Environment.
Here’s a look at the timeline for Phase I dredging operations at Redmond, including the start of the planning process. From 2012 through 2015, the Kansas Water Office worked with the Corps of Engineers to determine the feasibility of a dredging project at Redmond, then initiated the process of developing a Section 408 request and Programmatic Environmental Impact Statement.
Earth work started on construction of the CDFs in November 2015 and enough capacity was built to be able to start dredging operations in May 2016. By October 2016, 3,000,000 cubic yards of sediment had been removed from Redmond and Phase I dredging operations were complete. With the removal of this sediment, almost 1,900 acre-feet of water supply storage capacity was restored within John Redmond Reservoir. From the completion of Phase I dredging operations through today, CDF dewatering activities have been taking place which will ultimately allow for reclamation of the disposal sites.
Now we’ll briefly look at some pictures of the project, beginning with some of the construction activity associated with CDF construction. Overall, this phase of the project which built enough capacity to treat 3,000,000 cubic yards of dredged material lasted approximately 7 months.
Over 5 miles of pipeline was assembled to route dredged material from Redmond to the downstream disposal sites.
A slurry pipeline crossing of the Neosho River was built to route the dredged material to the disposal sites south of the Neosho. For this crossing we did acquire a Section 404 Permit from the Corps of Engineers.
The dredge itself was trucked in on a series of roughly 20 semis and put together onsite. This picture shows the dredge as it’s nearing completion and getting close to being pushed into the water in advance of dredging operations.
Great Lakes Dredge & Dock Company out of Oak Brook, Illinois was the company which won the design-build contract for dredging operations at Redmond. The dredge utilized at Redmond was the Dredge “LP”. On the right picture you can see a portion of the cutter head on the dredge.
The LP is an electric powered dredge which had power supplied to it via a line which was attached to the floating slurry pipeline. A fleet of support vessels was also in place including a crane barge, tug boats, a survey vessel, crew boats, and a skidder barge to provide sufficient workforce for dredging operations.
One booster pump was necessary to help push the dredged material to the downstream disposal sites. This booster pump was placed on the north side of Damsite Park just to the west of the northern extent of the Redmond dam embankment. With this booster pump in line, there was enough power in place to push the dredged material out to CDF I-South, the furthest disposal site away from the dredge.
On May 17, 2016, a kickoff ceremony took place at Redmond to commemorate the start of dredging operations. Dredging at Redmond is a significant event in that this project represents a first of its kind in the nation with a non-federal agency sponsor conducting a large-scale inland dredging project on a U.S. Army Corps of Engineers reservoir. This project will serve as a model both in Kansas as well as nationwide for water supply restoration efforts within federal reservoirs. With dredging starting on a notable project such as this we wanted to celebrate and recognize the significance of this event.
This video shows dredged material being placed into CDF E, the largest of the 5 disposal sites utilized for the project. As you can see the material is very dark and muddy in appearance and approximately 80% and 20% dredged material. This ratio can be modified to increase the amount of solids contained within the slurry mix depending on dredging rate as well as material composition.
From the previous video, those solids within CDF E settled out and then were routed to CDF B, the final clarification cell of the disposal system. Notice how much cleaner the water is in comparison to the previous video. No flocculants were utilized to help with settling out of solids within the CDFs.
With the additional settling time in CDF B, the effluent water was ready for discharge into the Neosho River. This is the point of discharge into the river and note the clarity of the water.
Here is a view of John Redmond in the background with 3 of the disposal sites in the foreground, CDFs I-South, I-North and E. The small area between I-South and I-North was not utilized for sediment disposal to avoid impacts to jurisdictional Waters of the U.S.
CDF dewatering activities have been taking place which will ultimately allow for reclamation of the disposal sites.
CDF F (no water)
CDF E (with water)
Breakdown on major project cost components as follows: CDF Construction = 23%, Sediment Removal = 44%, Land Reclamation = 11%, Land Lease Payments = 3%, Electrical Infrastructure Upgrades = <1%