(5.4) OPINION - Rodman Dam Spillway: Why Not Just Remove the Floodgates?

Rodman Dam Spillway
Why Not Just Remove the Floodgates?


Rodman Dam Spillway with its four 40-foot wide floodgates above a 6-foot elevation concrete crest



An Information, Opinion, Photos, & Sources Report
Compiled by Ocklawahaman Paul Nosca
Created: 24 February 2016
Last Revised: 21 October 2019

 

 

NOTE:  Click-on individual photos to enlarge them!



THE SCIENTIFIC DATA THAT WE NOW KNOW

The SJRWMD "Technical Publication SJ2016-1" by John Hendrickson contains the data -- about DISSOLVED SILICA, NITROGEN, and PHOSPHORUS (and their combined effects on possible [downstream] St. Johns River harmful algal blooms) -- best supporting that the restoration of the Ocklawaha River will be beneficial for the entire St. Johns River (Florida's ONLY "American Heritage River") basin.

The findings of "Technical Publication SJ2016-1" report that the potential downstream detrimental nutrient load to the St. Johns River estuary by a free-flowing Ocklawaha River will be much less than previously predicted (by old 1999 science) and at these lower levels can probably be mitigated in other sections of the St. Johns River basin using measures and procedures known to SJRWMD.

Hendrickson, John. 2016. Effects on Lower St. Johns River Nutrient Supply and TMDL Target Compliance from the Restoration of a Free-Flowing Ocklawaha River. Technical Publication SJ2016-1. 107 pages. St. Johns River Water Management District, Palatka, Florida is available at: ftp://secure.sjrwmd.com/technicalreports/TP/SJ2016-1.pdf


SO AN ENVIRONMENTAL RESOURCE PERMIT (ERP) FOR OCKLAWAHA RIVER RESTORATION COULD PROBABLY BE APPROVED BY SJRWMD SOON -- BUT WHAT ABOUT THE MONEY???
WELL, MAYBE IT COULD BE DONE MUCH MORE CHEAPLY THAN PREVIOUSLY THOUGHT!


MY OPINION

Just a thought that I have had again lately -- especially during drawdowns of Rodman Reservoir (a.k.a. Lake Ocklawaha or Rodman Pool). Why do we not go ahead with the 3-year orderly drawdown of Rodman Reservoir that was envisioned by "The Governor and Cabinet, sitting as the Board of Trustees of the Internal Improvement Trust Fund" back in 1995? See the excerpted paragraphs further below in this web-page.

At the end of the third year just open and/or lift the four 40-foot wide floodgates to their maximum height above the 6-foot elevation concrete crest of the Rodman Dam (a.k.a. Kirkpatrick Dam) spillway and let the 160-foot wide Ocklawaha River (in 4 channels) flow through it! Later on, maybe remove the four floodgates completely.

Yes, for only a short time perhaps, there will be a man-made falls or shoals during periods of lower river flows -- which could become a popular "white water" tourist attraction (canoes and kayaks) for Putnam County, Florida.

As a US Army veteran, I have complete trust that the Corps of Engineers has the equipment available that would allow them to modify parts or all of those four open 40-foot wide flowing channels with a 6-foot elevation concrete crest to allow for better navigation by both powerboats and manatees.

The just above Rodman Dam segment of the Ocklawaha River would scour a channel over to the Rodman spillway and would use the existing tailrace channel downstream to flow towards the natural lower section of the Ocklawaha River and the St. Johns River.

Artesian springs along the river would flow again and the massive evapotranspiration of the stagnant man-made impoundment would be greatly reduced -- resulting in more freshwater flowing towards the St. Johns River.

The vehicle bridge and roadway would still be usable along with the boat ramp and restrooms.

Fishing below "Rodman Falls" from the present existing facilities will continue. But an open spillway will allow migratory fish species to once again be able to travel between the St. Johns River and the Ocklawaha River up as far as Silver River, Silver Springs, and Moss Bluff. LARGEMOUTH BASS angling will continue to be outstanding in the riverine environment and there will be seasonable STRIPED BASS "runs" as well up to Silver River or beyond. Atlantic-race STRIPERS can reach 30 pounds or more -- a great Florida-native (historically) gamefish that needs a suitable spawning habitat once again in the St. Johns River basin -- instead of depending on the State of South Carolina to provide Atlantic-race STRIPED BASS for stocking in Florida waters.

The Cross Florida Barge Canal in Rodman Reservoir with its 6-foot elevation bottom will basically become dry ground or a shallow wetland.

VERY LOW COST and IS IT SOMETHING TO CONSIDER?



Eureka Dam Spillway
Downstream Side
Two 40-foot wide floodgates
NO water flows over its 26-foot elevation crest

Eureka Dam Spillway
Downstream Side
Two 40-foot wide floodgates
NO water flows over its 26-foot elevation crest

Eureka Dam Spillway
Upstream Side
Two 40-foot wide floodgates
NO water flows over its 26-foot elevation crest



EXCERPTED COMPLETE PARAGRAPHS FROM:

Muller and Associates, Inc. 2007. Marjorie Harris Carr Cross Florida Greenway management plan (15 June 2007). Prepared with Office of Greenways and Trails, Florida Department of Environmental Protection, Tallahassee, FL.

http://www.dep.state.fl.us/gwt/cfg/Plan_PDF/CFG_LMP_Final.pdf


Numerous groups have urged the removal of the Kirkpatrick (formerly Rodman) Dam and restoration of Rodman Reservoir to the Ocklawaha River floodplain since the 1970s because of the impact of the reservoir on the Ocklawaha River and floodplain and associated ecosystems. There is resistance to this from other groups such as sports-fishing related organizations and businesses. The Governor and Cabinet, sitting as the Board of Trustees of the Internal Improvement Trust Fund, have an established policy that the Ocklawaha River should be “partially restored” (see explanation below), with the Florida Dept. of Environmental Protection as the lead agency. However, the Legislature has not appropriated funds for this purpose. If funds are made available and permits are issued, it is the intent of FDEP to undertake this restoration. SJRWMD is investigating the potential impact on the St. Johns River from restoration of the Ocklawaha.

Kirkpatrick Dam caused the flooding of a portion of Ocala National Forest lands. The flooding and occupying of these lands was allowed under a special permit from the U.S. Department of Agriculture Forest Service first issued in 1994. This special permit expired in 2002. DEP applied for a new permit, but the Forest Service included conditions about the issuance of the new permit, including a schedule for the reservoir to be drawn down and the dam to be breached. The Secretary of DEP did not sign the Forest Service permit because the permit(s) from SJRWMD necessary to draw down the reservoir had not been approved.

“Partial restoration”, the restoration alternative selected by the Governor and Cabinet in 1995, is intended to restore river hydrology and floodplain function to near preconstruction conditions through breaching of the dam, with limited removal and/or alteration of structures and alteration of topography. This alternative will retrieve National Forest System lands at the lowest cost while restoring river and floodplain hydrology. The major components of partial restoration are:

1. Drawdown of the reservoir to be accomplished in 3 phases (three years to drop from 18 to four feet
National Geodetic Vertical Datum).
2. Limited construction of channel stabilization and erosion control structures in the Ocklawaha River.
3. Limited planting of native plant species to provide for erosion control.
4. Partial leveling of the exposed barge canal side-cast spoil berms.
5. Restoration of the historic Ocklawaha River channel flow by filling the barge canal where it intersects the river channel.

6. Restoration of the historic Deep Creek channel flow by filling the barge canal where it intersects the creek channel.
7. Restoration of the historic Camp Branch floodplain and channel flow by filling the barge canal where it
intersects the creek channel.
8. Closure and securing of the Buckman Lock.
9. Removal of 2,000 feet of the Kirkpatrick dam (earthen portion).
10. Partial filling and restoration of the spillway tailrace to natural grade.
11. Development and implementation of a cultural resources operating plan.

The projected cost for repairs and to bring the Buckman Lock, Kirkpatrick Dam and Spillway and the Eureka Lock and Dam up to latest standards for operation is $14.1 million. This estimate is based on the April 2005 inspection report and years of historical data from the Inglis Lock and Dam repair projects and assessment reports. The estimated cost for restoration of the Ocklawaha River is $25.8 million. The yearly operating costs for the dam components and activities and the operating costs for the area after restoration are approximately the same, $198,000 and $234,000 respectively. Snagging for navigation maintenance is expected to increase after river restoration, contributing to almost half of the annual operating cost after restoration.



REFERENCE AS:  Nosca, P. 2019. "Rodman Dam spillway: why not just remove the floodgates?" webpage report. "Ocklawahaman Paul Nosca reports" website. Paul Nosca, Eureka, FL. 
https://sites.google.com/site/ocklawahamanpaulnoscareports/rodman-dam-spillway-why-not-just-remove-the-floodgates

 

Email: ocklawahaman1@gmail.com

 

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