WQC Info Item Jan 2024 - Yadkin & South Yadkin Rivers Reclassification - WS CA and PA Boundaries

Elizabeth Liebig
Classifications and Standards Branch
Division of Water Resources
Information Item: Reclassification of Portions of the Yadkin River, South Yadkin River, and
Associated Tributaries in Rowan, Davie, and Davidson Counties (Yadkin Pee-Dee River
Basin) to Class WS-IV Critical Area (CA) and Class WS-IV Protected Area (PA)
January 10, 2024
Purpose of Today’s Information Update
•Provide background on upcoming Water Supply reclassification
•Review rules that apply to the delineation of Critical and Protected Areas in Water Supply Watersheds
•Review the Salisbury-Rowan Utilities (SRU) proposal
•Provide additional information requested by WQC during November 2023 meeting
•Summary of studies pertaining to the river and reservoir hydrodynamics in this area
•Review of Critical Area (CA) and Protected Area (PA) maps
•Receive WQC feedback on Critical and Protected Area Boundary approach
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Intake Locations
Existing Intake
Proposed Intake
Normal Pool Elevation of
High Rock Lake reservoir
Delineating Critical and Protected Areas
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•15A NCAC 02B .0202 items (20) and (48) – define the CA and PA boundaries, respectively
•Subpart (a) applies to a water supply intake within a reservoir
•Item (48)(a) - extending either five miles in an as-the-river-runs manner upstream from and draining to
the normal pool elevation of the reservoir in which the intake is located or to the ridge line of the
watershed, whichever is nearest the normal pool elevation of the reservoir;
•Subpart (b) applies to a water supply intake within a stream or river
•Item (48)(b) - extending either 10 miles in an as-the-river-runs manner upstream from and draining to
the intake located directly in the stream or river run-of-the-river or to the ridge line of the watershed,
whichever is nearest the intake. In some cases the protected area shall encompass the entire
watershed;
•Subpart (c) allows the EMC to approve a different distance for the CA and PA
•Item (48)(c) - extending a different distance from the reservoir or intake as adopted by the
Commission during the reclassification process pursuant to Rule .0104 of this Subchapter
•This reclassification is being proposed under 15A NCAC 02B .0202 items (20)(c) and (48)(c)
Critical and Protected Areas for an Intake Within a Reservoir
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Proposed Intake
Existing Intake
Approximate Protected Area
following reservoir rule language
High Rock Reservoir boundary
Approximate Critical Area
following reservoir rule language
SRU Proposal for Critical and Protected Areas
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•SRU will be requesting that portions of the Yadkin River / HRL reservoir, South
Yadkin River / HRL reservoir and associated tributaries be reclassified to Class
WS-IV with the CA and PA extending a different distance from the reservoir or
intake as adopted by the Commission1
•Because the current intake predates the construction of the dam and was treated
as riverine, SRU will be requesting that the EMC support the same approach for
this relocated intake
•SRU Approach – Delineate Protected and Critical Area boundaries as if the water
supply intake was within a stream or river:
•extending either 10 miles in an as-the-river-runs manner upstream from and draining to
the intake located directly in the stream or river run-of-the-river or to the ridge line of
the watershed, whichever is nearest the intake2
1. 15A NCAC 02B .0202 (20)(c) and (48)(c)
2. 15A NCAC 02B .0202 (48)(b)
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Critical and Protected Areas for an Intake Within a River
Proposed Intake
Existing Intake
High Rock Reservoir boundary
Protected Area following
riverine rule language
Critical Area following
riverine rule language
Reservoir Zones of High Rock Lake Reservoir
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•Water flow in reservoirs are categorized
into 3 zones: riverine, transitional, and
lacustrine (Cooke et al 2005)1
•Chemical and physical properties of the
“upper” regions of High Rock Lake
reservoir are riverine in nature (Rudd
2018)2
Figure 1: Longitudinal zonation within reservoir basins1
1.Cooke, G.D., Welch, E.B., Peterson, S.A., and Nichols, S.A.(2005). Restoration and
Management of Lakes and Reservoirs. Taylor and Francis Group. Boca Raton, FL.
2.Rudd, M. (2018).An Evaluation of Water Quality Parameters and Flow Dynamics in High
Rock Lake, North Carolina to Assist in the Development of Nutrient Criteria for Lakes and
Reservoirs in the State. Master of Environmental Management Degree Candidate. Duke
University.
Existing Intake:Increased Bed Elevations
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•Doyle Report2 concludes:
•The bed elevation at SRU’s existing intake has increased
more than 10 ft since the intake was constructed in 1917
(prior to dam construction and the establishment of the
reservoir)
•The dam and its sediment delta are the primary causes of
increased water surface elevations at the current intake
Figure 2: Example reservoir sediment profile1
1.Randle, T.J. and Bountry, J.A. (2017). Sediment Analysis Guidelines for Dam Removal. U.S.
Department of the Interior, Bureau of Reclamation for the Federal Advisory Committee on
Water Information, Subcommittee on Sedimentation, Denver, CO.
2.Doyle, M. 2007. High Rock Dam and Sediment Delta Flooding and Sedimentation Effects
(1927-1959) on City of Salisbury Critical Infrastructure.
Water Flow in the Upper Regions of High Rock Lake Reservoir
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•Water was modeled as “having a uniform,
bounded cross-section with steady,
unidirectional flow of 735 cubic feet per
second (cfs)” at Salisbury-Rowan WWTP
(CORMIX Analysis 2006)1
1.CORMIX Analysis. (2006). Salisbury-Rowan Utilities Technical Report. Salisbury-Rowan
WWTP Yadkin River Diffuser. January.
2.Kostic, S. and Parker, G. (2003). Physical and Numerical Modeling of Deltaic Sedimentation in
Lakes and Reservoirs. International Association of Hydraulic Research Congress. August.
Figure 3: Typical structure of a deposit in a reservoir2
Comparison Map of Critical and Protected Areas
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Approximate Protected Area
following reservoir rule language
High Rock Reservoir boundary
Approximate Critical Area
following reservoir rule language
Critical Area following
riverine rule language
Protected Area following
riverine rule language
Proposed Intake
Existing Intake
Existing Protected Area for
Tuckertown Reservoir
Critical and Protected Area Comparison Table
Approximate Area
for an Intake
Within a River
(square miles)
Approximate Area
for an Intake
Within a Reservoir
(square miles)
Approximate
Difference
Between Scenarios
(square miles)
Critical Area 0.4 86 85
Protected Area 66 309 243
Total
(Critical and Protected Areas)66.4 395 328
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Next Steps for Rulemaking
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Winter 2023 –
Spring 2024
•Conduct study of waters to be reclassified (DWR)
•Obtain local government resolutions (SRU)
•Prepare rulemaking package with fiscal analysis (DWR)
May 2024 •WQC Approval to Proceed to EMC
July 2024 •EMC Approval to Proceed to Public Notice
August – October 2024 •Public Notice and comment period
January 2025 •EMC Adoption
Project/Funding Timeline:
•Spring 2024 BRIC FEMA Grant Award
•Summer 2024 Bidding and Contract Execution
•Fall 2024 NTP Construction Contract
•Fall 2026 Completion of Construction Contract (2-year estimated duration)
•Spring 2027 Project Completion (FEMA BRIC Grant must be expended & project completed within 3 years of award)
Questions?
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Elizabeth Liebig
Classifications Coordinator
[e-mail]
Phone: [phone]
Paul Wojoski
Branch Supervisor
[e-mail]
Phone: [phone]