Lake Louise Dam reclassified, Emergency Action Plan adopted

Editorial Note: No timeline has been ascertained for the completion of the necessary work to repair the noted conditions. ConnectLocal.News has contacted project engineers to obtain an estimated time for the re-opening of Lake Louise Road, and will update this story as soon as that information is made available.

Video of Lake Louise leveldown - taken by ConnectLocal.News last week. The first video is the spillway drain, the second is the discharge into the plunge pool.

With a unanimous vote Tuesday, Stephens County Commissioners approved a new Emergency Action Plan (EAP) for the Lake Louise Dam. This plan, a coordinated effort between county officials, the county Emergency Management Agency, dam owners and the Georgia Safe Dams Program, outlines in detail a plan of action to be taken in the event of “an emergency associated with the Lake Louise Dam, which is caused by an unusually large flood, earthquake, a malfunction (hydraulic or structural) of the spillway, malicious human activity such as sabotage, vandalism, or terrorism, or the failure of the dam.”

The adoption of the EAP is the culmination of a months-long process involving several physical and regulatory changes regarding the Lake Louise Dam, but is in no way indicative of any current or expected safety concerns with the dam, county officials emphasized.


Although the Lake Louise Dam will now be classified, permitted and monitored as a Category I dam under the Georgia Safe Dams Act and program guidelines, as opposed its existing Category II classification, since there are currently no habituated structures within the dam’s flood inundation zone, the dam will not pose a threat to life even in the event of dam failure, County Administrator Phyllis Ayers and Stephens County EMA Director Danielle Rhodes stated.

“A Category I classification is not an indication of the condition of the dam. The classification relates to the hazard potential should the dam fail for any reason. In addition, the classification is not an indication of the likelihood of failure,” states Safe Dams Program documentation.

Within the documentation of the EAP, under the heading of “Residents/Businesses/Highways at Risk, it is stated that “A major flood caused by a sudden breach of the dam is estimated to inundate 0 homes, 0 businesses, 1 Railroad (Norfolk Southern Railroad) and 2 Roadways (Lake Louise Road, Riverdale Road)


The Dam

Lake Louise Dam, a 76-foot high dam built in 1937, is located at the eastern boundary of Lake Louise, along Lake Louise Road, just to the north of E. Currahee Street/Hwy. 365/Hwy. 123. The identified drainage area is 1920 acres (3 sq. miles) and drains into Lake Hartwell. The dam, up until the adoption of the EAP and the current work being conducted on the dam, was classified as a Category II dam.


The Georgia Safe Dams Act/Program

Pursuant to the Georgia Safe Dams Act, the Safe Dams Program is responsible for developing and maintaining an inventory of dams, classifying dams, and ensuring compliance of all regulated dams. The Safe Dams Program is also responsible for working with dam owners on their compliance with the Act and corresponding rules, and where necessary, taking enforcement actions against owners who do not comply with the Act and Rules.


Dam Classifications

The three main classifications of dams described in the Act and Rules are “Category I”, “Category II”, and “Exempt”. To be considered a Category I dam, the improper operation or failure would result in a probable loss of human life. The Georgia Safe Dams Act requires permits for these projects. Dams that meet the height and/or storage criteria but would not cause probable loss of life are classified Category II. Exempt structures include any dam that is licensed by the Federal Energy Regulatory Commission, structures constructed as part of EPD approved surface mining, any dam owned by the United States Government, any structure that is not greater than 25 feet in height and impounds less than 100 acre-feet of water, any structure that is not greater than 6 feet in height regardless of storage volume, and any structure that impounds less than 15 acre-feet regardless of height. Permits are not required for Category II or exempt structures.


The Lake Louise Dam has been classified, throughout its history, as a Category II dam due to the fact that there is no predicted loss of life in the event of dam failure, attributed largely to the fact that there are no habited structures within the inundation zone. Dams that are re-classified from a Category II dam to a Category I dam by command of the Safe Dams Program are often reclassified because of the building of habitable structures within the inundation zone.


The reclassification of the Lake Louise Dam from a Category II to a Category I dam is not being ordered by the Safe Dams Program, as it still qualifies as a Category II dam since there is no loss of life predicted in the event of a dam failure, due to the fact that there are no habited structures within that inundation zone.


The change to a Category I dam is a voluntary, proactive choice by dam owners, The Georgia Baptist Mission Board, in order to meet the higher structural guidelines for a Category I dam, and to have an EAP in place, in the event that, in the future, there are habitable structures built within the inundation zone, said Ayers.


In-Progress Work

Current work on the dam is being undertaken to address issues identified in the “current dam condition” as set forth in the EAP:


“The current components to the dam are the primary and auxiliary spillway. There is no low level lake drain. The primary spillway is a 42” diameter steel vertical riser connected to a 24” steel pipe. The riser is located 40’ from the shore on the northern side of the lake. There is an inoperable valve on the primary spillway. The emergency/auxiliary spillway is a 78” steel pipe located along the shoreline +/- 220’ north of the primary spillway. This pipe discharges into an 8’ wide by 65’ long concrete flume. The last +/- 30’ of the flume is cantilevered due to severe erosion and should not be entered. There is also a 24” steel pipe located on the southern side of the dam near the Calhoun property line. This pipe daylights at the toe of the slope. It is not Operational and should not be flowing.”


On the initial, and only, event log for the Lake Louise Dam included in the EAP, it is stated that “In order to assess the condition of the 24” steel conduit at the bottom of the dam, a cleaning and video camera inspection was performed by Continental Pipe Services under the observation of (the engineers). The following situations were identified:


Break/gap found in the conduit. Exposed soil and seepage flow was observed; longitudinal cracking at multiple locations; corrosion and general deterioration on the lower half of conduit; holes in walls of conduit due to corrosion at numerous locations; pipe distortion and ovalization.


Recommendations from engineers to address above observations included “lowering the lake 10 feet and reevaluate. The lake is to remain at lowered pool until permanent repairs are initiated.”


The EAP

The EAP, drafted following the Safe Dams Program template and guidelines, defines responsibilities and procedures to “identify unusual and unlikely conditions that may endanger the dam, initial remedial actions to prevent a dam failure or minimize the downstream impacts of a dam failure, and initiate emergency actions to warn downstream residents of impending or actual failure of the dam.”


The prescribed evacuation area, in the event of emergency event judged under specified guidelines to necessitate evacuation, “includes the Lake Louise Road, the Norfolk Southern Railroad, Riverdale Road, and the docks near Walton Creek’s exit into Lake Hartwell. Habited structures are not effected,” states the EAP.


Under the EAP, there are three levels of events, with corresponding levels of response.

Level 1 – Unusual event, slowly developing

Level 2 – Emergency event, potential dam failure situation, rapidly developing

Level 3 – Urgent emergency event, dam failure imminent or in progress.


Responses to the various levels include notification of a hierarchy of private and local and state governmental contacts, as well as public notification.


“After event level has been determined, notifications are made in accordance with the appropriate notification flow chart provided in the EAP.”

“After the initial notifications are made, the EAP Coordinator should confer with the site engineer and the Georgia Safe Dams Program to develop and execute appropriate preventative actions. During this step of the EAP, there is a continuous process of taking actions, assessing the status of the situation, and keeping others informed through the communications channels established during the initial notifications.”



FYI

* There are 18 dams in Stephens County, three of which are classified by the Safe Dams Program as Category 1 dams.


* There is currently a bill being considered by the Georgia General Assembly that amends the regulations and requirements for Category II dams.


Senate Bill 319 Passed the Senate on Feb. 24 with a 47 yea, 6 nay, 2 not voting, 1 excused vote. Senator John Wilkinson voted "yes." The bill will now be taken up by the House.


SB 319 Text: A BILL to be entitled an Act to amend Part 3 of Article 5 of Chapter 5 of Title 12 of the Official Code of Georgia Annotated relating to rivers and river basins relative to dam safety, so as to prohibit the building of inhabitable structures in the inundation zone of a Category II dam without prior certification from an engineer of record; to provide for an engineer of record to perform and certify a breach analysis where inhabitable structures already exist in the inundation zone of a Category II dam; to provide for filing of the certified breach analysis; to provide for the development of building standards for inhabitable structures in the inundation zone of a Category II dam.

126 views
QuincysSideBanner.jpg
KeepLocalNewsComing.jpg

© 2020 ConnectLocal