During Federal Energy Regulatory Commission relicensing of its
16-MW Ozark Beach project, The Empire District Electric Company worked to redefine the project boundary and remove land not required for project operation, thus simplifying this portion of the process.
By Sarah Howard and Kyle Slagle
The Ozark Beach Hydroelectric Project, originally constructed in 1913, is owned and operated by The Empire District Electric Company. Ozark Beach is a Federal Energy Regulatory Commission (FERC)-licensed, 16-MW run-of-river project located on the White River in south-central Missouri. The dam is 1,300 feet long.
The project includes a 2,200-acre impoundment (Lake Taneycomo) located between two federal hydropower projects, owned and operated by the U.S. Army Corps of Engineers: 200-MW Table Rock (upstream) and 340-MW Bull Shoals (downstream).
The existing project boundary encompasses large blocks of land, some of which extend well beyond the lake shoreline. However, not all of this land is necessary for operation and maintenance of the project.
Empire initiated FERC relicensing of the Ozark Beach project in September 2015, as the current operating license expires in 2022. Work successfully completed to date includes the notice of intent/pre-application document (NOI/PAD), the public review period, and the joint meeting. Work is now under way to complete a recreation resources study, a Phase I cultural resources study, an erosion study, and a downstream aquatics study. The next phase will be to complete the draft license application.
As part of the relicensing process, Empire has proposed to revise the project boundary to exclude land that is no longer required for project operation. The existing project boundary encompasses about 6,295 acres (including water), and the proposed boundary encompasses about 2,242 acres (including water). Doing so will reduce the administrative cost and burden on Empire and FERC. Empire hired Black & Veatch to perform the work required to revise the project boundary.
This article presents the approach Empire took to establish the FERC project boundary, which typically relates to the “normal maximum surface elevation” of the reservoir. For Lake Taneycomo, streamflow is heavily influenced by releases from Table Rock Dam, making it difficult to identify the “normal” and “maximum” elevations.
Identifying the land
The first step in revising the project boundary was to define the normal maximum surface elevation of the impoundment. Because flows and surface elevations in Lake Taneycomo are dictated largely by the operation of Table Rock Dam upstream, it was necessary to first establish a “normal maximum” flow release from Table Rock Dam, then model the corresponding impoundment elevation to arrive at the “normal maximum surface elevation.”
Using current and historical hourly flow data provided by USACE, 13,500 cfs was selected as the normal maximum flow release from Table Rock Dam. This value represents the maximum hourly Table Rock Dam release and corresponds to the about 5% exceedance value on the project’s flow duration curve. As such, it is a conservative value that has been presented to FERC as appropriately representing the normal maximum flow condition.
The revised project boundary for the impoundment was established by calculating the normal maximum surface elevation that corresponded to the 13,500 cfs normal maximum flow release from Table Rock Dam. Black & Veatch completed this work using an existing HEC-RAS model from USACE that was developed in 2000 for the White River.
The resulting contour represented the normal maximum surface elevation and, thus, the revised project boundary for Ozark Beach (see Figure 1). In several areas where the revised boundary extended beyond the existing boundary, the existing project boundary configuration was adopted or the 200-foot offset stipulated in the FERC regulations was implemented.
Figure 1 Revised Project Boundary
The revised project boundary will:
• Exclude properties within the existing project boundary that are not “…necessary for operation and maintenance of the project or for other project purposes…” and thus, more closely adhere to the provisions of 18 CFR 4.41(h)(2).
• Continue to include and protect project-related recreational facilities and environmental resources, all of which are retained within the revised project boundary per the requirements in 18 CFR 4.41(h)(2)(i)(B).
• Contract the project boundary around the impoundment to more closely conform to the requirements of 18 CFR 4.41 (h)(2)(iii)(B).
Obtaining FERC approval of the proposed project boundary has been incorporated into the relicensing process, as opposed to it being submitted separately as an amendment to the current operating license. Combining the proposed project boundary with the relicensing provided for a streamlined approach to the overall FERC process.
The proposed project boundary will not change the hydro project’s operation or maintenance procedures, affect the current ownership or properties, or result in any significant adverse impacts to environmental resources, local landowners, residents, businesses, community services or infrastructure. It also will not extend beyond the existing project boundary, which has been sufficient, without any known complaints or issues, for many years.
The application for transfer of project lands was filed with FERC on Dec. 5, 2016. In it, Empire requested approval to transfer fee title of 23.9 acres, or about 3,500 linear feet, within the boundary of the project to private property owners. The transfer of land ownership would be subject to retaining a flowage easement that would permit Empire to operate and manage the reservoir as required by the project’s license.
The proposed project boundary for Ozark Beach is currently under FERC review.
Sarah Howard is a senior environmental scientist in the consulting engineering services/renewable services business line of Black & Veatch’s global energy business. Kyle Slagle is director of water operations with The Empire District Electric Company.