Lowhead Dam Removal Case Study

St. John's Dam - Sandusky River

Historical Information

1. Dam Name: St. John's Dam - Sandusky River

2. Estimate height of dam in feet - 150' length 7' 2' height

3. Dam Type:

a) earthfill dam
b) concrete arch dam - X
c) gravity dam
d) masonry dam
e) timber cribs
f) other, please explain

4. Location Description: St. John's Dam located on the Sandusky River in Seneca County near the intersection of County Rd. 6 and Township Rd. 131.

5. Year Constructed: Early 1900's    Year Removed: 2003

6. Dam Owner:

a) public - X Ownership transferred to ODNR, 03/11/03
b) private - X - Ohio American Water Company
c) abandoned

7. Dam Function:

a) generate hydropower
b) irrigation
c) domestic water supply - X discontinued 1988 following the drought
d) navigation
e) flood control
f) recreation
g) industrial water supply
h) unknown

8. What repairs have been done to the dam? _______________

9. Reason(s) for Removal:

a) aesthetic enhancement - X
b) fish and wildlife habitat improvement - X
c) cost savings
d) community revitalization - X
e) public safety hazard - X
f) water quality improvement - X
g) recreational improvement - X
h) alternative to dam

10. Project Sponsor (who initiated project): The project was initiated by Ohio American Water Co. who owned the dam. They agreed to turn St. John's Dam over to the Ohio Department of Natural Resources (ODNR) Division of Natural Areas and Preserves who wanted to remove the dam because it was a hazard and no longer served its intended purpose. ODNR then entered into an agreement with the Ohio Dept. of Transportation (ODOT) to have the dam removed. ODOT agreed to remove the dam and pay all removal costs as part of mitigating a highway project that was recently completed nearby. This dam removal project is now referred to as the St. John's Dam Pooled Stream Mitigation Area (PMSA).

11. Dam Removal Funding Sources:

a) federal -
b) state - X
c) local governmental agencies
d) other (please explain)

12. Cost of Dam Removal: $79,000

13. List all Contractors by Name, include Address and Telephone #:

1) Mosser Const., Tiffin, OH

14. Permits Required:

a) federal - A 404 permit was not required because the work did not involve a discharge of dredged or fill material into the river. The concrete debris was removed from the river to an upland location the same day it was demolished.
b) state
c) municipal

15. Dam Photographs:

a) before removal - X
b) during removal - X
c) after removal - X

16. Problems Encountered

a) before removal - A local landowner whose property is on the Sandusky State and Scenic River expressed concern with the breaching of St. John's Dam. He also objected to the use of public funds to cover the cost of removal. DNR responded to his objections and continued to proceed with the project.

b) during removal - As part of the pre-dam removal data set at the St. John's Dam, a team of OSU researchers was preparing to deploy equipment and make some morphological/hydraulic measurements in the channel on the morning of November 14, 2003. The dam was breached early and as a result the researchers were unable to deploy five bed load traps. In addition, they were also prevented from conducting transects across the downstream channel to measure current velocities and bed topography. Unfortunately, water levels remained high that weekend. Consequently, they were unable to deploy the remaining traps before the complete removal of the dam on Monday, November 17, 2003. The data from these traps and surveys would have been important for quantifying bed load transport associated with the removal.

When the dam was removed problems were encountered with sloughing of the banks near some homes. This problem was partially attributed to the fact that the dam was removed in a couple of hours, thereby creating high water levels downstream over the next couple of days. As a result, the banks became saturated with water and sloughing problems occurred. It is conceivable that had the dam been lowered and eventually removed over a couple of days it might have lessened this problem.

c) after removal - The Ohio Department of Transportation (ODOT) sent a Geotechnical Engineer to evaluate the sloughing problem that occurred at Locust Grove. After careful review, it was determined that the worst of the problems were over. The situation was compounded by the fact that the Locust Grove development was built primarily on fill material.

17. Before Removal:

a) Estimated Reservoir Area in acres - The dam impounds 14 river miles or 455 acre-feet of river.

b) Composition of river bed (eg. sand, pebbles, boulders, bedrock)- In 1998, ODNR?s Division of Geological Survey mapped the river bottom from the dam to four miles upstream and found no sediment load behind the dam. The riverbed consists of bedrock.

c) Types of Fish caught in the river - The Division of Wildlife has been studying the fish population through electroshocking and taking water samples at five sites. They are using the same sites from which data was taken after the Kirby Tire fire in 1999 so it can be compared to EPA data. The same sites were also used for an EPA total maximum daily load (TMDL) study in 2001. Above the dam, very few game fish were caught

d) Water Quality

i) behind the dam Good____ Fair____ Poor - X
ii) below the dam Good - X Fair____ Poor____

Comments:

18. Were any studies of the river conducted before the dam was removed?

Yes or No.
If yes, who conducted the studies and who is the contact for obtaining them?

19. Have studies been conducted on the river after the dam was removed to document changes in the river?

Yes ? X No
If yes, who conducted the studies and who is the contact for obtaining them?

 

ODNR will conduct Index Biotic Integrity (IBIs), Invertebrate Community Index (ICIs) and Qualitative Habitat Evaluation Index (QHEIs) at five existing OEPA habitat and biological monitoring sites above the dam and below the dam. The frequency of monitoring will be twice a year over the next five years.

ODOT will perform QHEIs every two miles on the main stem of the Sandusky River starting at the first riffle downstream of the dam to the riffle located at the end of the dam impoundment. The frequency will be once a year on the first, third, and fifth monitoring years following the removal of the dam.

ODNR, Division of Geological Survey will survey substrate composition and conduct channel morphology analysis for five years after removal of the dam.

The Ohio State University will conduct unionid mullusk inventories at the riffle below the dam and at one of the OEPA habitat and biological monitoring sites above the dam once every year for five years after the removal of the St. John's Dam.