Catawba-Wateree Groundwater Network

Science Center Objects

The multiyear drought in North and South Carolina (summer 1998-fall 2002) brought wide recognition of the vulnerability of the water resources in these two States to climatic conditions. To prepare for drought conditions in the future, water managers and State and Federal water-resource agencies sought to develop tools to assess hydrologic conditions in both a predictive and responsive manner. USGS partnered with the Catawba-Wateree Water Management Group to establish a monitoring network of near real-time streamflow gages (surface-water stage/discharge) and wells (groundwater levels), which are the essential components for assessing hydrologic conditions.

The multiyear drought in North and South Carolina (summer 1998-fall 2002) brought wide recognition of the vulnerability of the water resources in these two States to climatic conditions. To prepare for drought conditions in the future, water managers and State and Federal water-resource agencies sought to develop tools to assess hydrologic conditions in both a predictive and responsive manner. USGS partnered with the Catawba-Wateree Water Management Group to establish a monitoring network of near real-time streamflow gages (surface-water stage/discharge) and wells (groundwater levels), which are the essential components for assessing hydrologic conditions.

Introduction

Picture of a truck used to drill groundwater wells.
Air Rig in position to drill. Photo by Eric Rudisill, USGS(Public domain.)

The multiyear drought in North and South Carolina (summer 1998-fall 2002) brought wide recognition of the vulnerability of the water resources in these two States to climatic conditions. To prepare for drought conditions in the future, water managers and State and Federal water-resource agencies sought to develop tools to assess hydrologic conditions in both a predictive and responsive manner. USGS partnered with the Catawba-Wateree Water Management Group to establish a monitoring network of near real-time streamflow gages (surface-water stage/discharge) and wells (groundwater levels), which are the essential components for assessing hydrologic conditions. To prepare for drought conditions in the future, water managers and State and Federal water-resource agencies are seeking tools to assess hydrologic conditions in both a predictive and responsive manner. Monitoring networks of near real-time streamflow gages (surface-water stage/discharge) and wells (groundwater levels) are essential components typically used to assess hydrologic conditions.

The Catawba River originates in North Carolina and flows east and south into South Carolina. Downstream of the Lake Wateree Dam the river name changes to the Wateree River. For the area of the monitoring network, the Catawba River Basin (CRB) is defined upstream as tributaries to Lake James in North Carolina, and continuing downstream to the Lake Wateree Dam in South Carolina.

The groundwater component of the hydrologic cycle is often overlooked in basinwide water-resource monitoring. Groundwater provides base flow to streams and is the primary streamflow component during drought conditions, and seasonally when rainfall/runoff is less frequent. Understanding the relations between groundwater and surface water is essential to efficient management of the resources by water-supply planners.

 

Background

During periods of drought (1998-2002 and 2007-2009), releases of water from the reservoirs required careful planning to maintain water-supply and in-stream flow requirements. The Catawba River flows through 9 counties in North Carolina and 5 counties in South Carolina. The Catawba-Wateree Federal Energy Regulatory Commission (FERC) Project number 2232) includes 13 hydropower stations and 11 surface-water reservoirs operated by Duke Power (http://www.duke-energy.com/lakes/levels.asp). Major reservoirs in the CRB are Lake James, Rhodhiss, Hickory, Lookout Shoals, Norman, Mountain Island, Wylie, Fishing Creek, and Wateree (fig. 1). These hydropower stations provide more than 800 megawatts of electricity and water supply for more than 1 million people in North Carolina (North Carolina Division of Water Resources, 2001). The Catawba-Wateree FERC project license was issued in 1958 and is currently being reviewed for renewal.

 

Drillers installing Lake Wateree Saprolite Well (KER 433). Photo by Bruce Campbell, USGS.

Drillers installing Lake Wateree Saprolite Well, photo 1
Drillers installing Lake Wateree Saprolite Well, photo 1(Public domain.)

As part of the FERC relicensing process, stakeholder groups that include more than 160 representatives from 97 different organizations are meeting to address common regional interests of citizens, river and lake keepers, fishermen, recreational boaters, property owners, industries, and State and Federal resource agencies. As an outcome of numerous stakeholder meetings, a “Catawba-Wateree Agreement-in-Principle (AIP)” was drafted. Attachment G within the AIP entitled, the “Low Inflow” of the AIP draft includes a section entitled, “Recovery from the Low Inflow Protocol (LIP) for the Catawba-Wateree Project”. Groundwater levels were identified as an essential component for determining hydrologic conditions. The goal of determining critical levels for groundwater conditions are to assist Duke Power toward the assessment of impending onset, or recovery from, drought conditions. Determination of critical groundwater levels for the CRB is inherently difficult because of the lack of long-term groundwater level data for the CRB. A long-term data set generally is needed to determine the magnitude of climatic effects on groundwater levels. Data collected from the newly constructed wells will be compared to existing long-term groundwater levels data from wells outside of the CRB.

Because of near real-time data-collection capabilities and experience with long-term data collection, the United States Geological Survey (USGS) was asked to design and construct a groundwater monitoring network for the CRB. This document contains descriptions of tasks proposed for the construction of a CRB groundwater network in North and South Carolina using existing USGS drilling capabilities and resources from ongoing cooperative USGS-State agency and national programs.

Objective

The objective of this project is to construct a groundwater-level monitoring network for the CRB to assist water managers in assessing hydrologic conditions, particularly during times of drought. The constructed wells (10 well clusters of two wells each) will be instrumented with near real-time water-level monitoring equipment with data available every hour via USGS web pages. These water-level data can be used to establish critical “trigger” levels for groundwater conditions, as part of the CRB water-resource monitoring effort. Scientists from both the USGS, Duke Power, and stakeholder groups will work together in an effort to assess hydrologic conditions and determine critical groundwater levels for the CRB.

 

Approach

 

Drilling a Regolith well. Photo by Eric Staub, USGS. Eric Staub, USGS

Because of the large study area and diverse hydrogeologic settings, 10 monitoring well stations are suggested to attain areal proximity to the 4 major reservoirs (Lake James, Norman, Wylie, and Wateree) and cover the regional geologic units (belts). Seven of the ten sites would be well clusters, including both regolith and bedrock wells, while the remaining five sites would consist of only regolith wells.

Drilling activities proposed as part of this monitoring network will consist of the construction 9 new regolith wells (6 in NC; 3 in SC) and 4 new bedrock wells (SC – 2 wells, contract drillers; NC – 2 wells drilled by NC DWQ or contract drillers).

Drilling a Regolith well. Photo by Eric Staub, USGS.
Drilling a Regolith well. Photo by Eric Staub, USGS.(Credit: Eric Staub, USGS. Public domain.)

The initial period of this project (2009-2011) will focus on the selection and access of drilling sites. Well-drilling locations will be selected based on their proximity to surface-water reservoir, designated regional geologic unit, and logistical access (including appropriate permits). Base flow analyses of available surface-water discharge data may be conducted to determine areal differences of groundwater contribution related to regional geologic unit. Each individual well-cluster drilling site also will be located outside of the influence of the surface-water reservoir (topographically higher than flood plains, or river terrace deposits) to obtain representative groundwater level data.

After drilling permissions and permits are obtained, the USGS drilling crew will mobilize to the selected locations. The USGS North Carolina Office operates a trailer-mounted auger drilling rig that will be used to construct 9 new regolith wells; 6 in North Carolina and 3 in South Carolina. Contract drillers will be utilized for the bedrock wells in NC and SC. If difficult drilling conditions arise in constructing the regolith wells at specific locations, an estimate of contract drilling costs will be obtained through an open bid process.

As the new wells are constructed, near real-time groundwater-level monitoring instrumentation will be installed. Raingages will be added if data are not available from nearby USGS raingages or other agencies. These data will be transmitted to the USGS Water Offices in North and South Carolina and made available to the partners on USGS web pages every hour. Data will be verified through field measurements and quality assured in accordance with USGS NC and SC Water Offices Groundwater Quality Assurance Plans.

DATA LINKS

Real-time data for the sites shown in the site location map at the top of this page are available at:

  • Site 1: Pleasant Gardens
  • Site 4: Lancaster County Airport
  • Site 5: Lake Wateree
  • Site 6: Langtree Peninsula at Lake Norman
    • IR-130 LANGTREE RS MW-2S NR MT MOURNE (Regolith well)
    • IR-131 LANGTREE RS MW-2I (Transition zone well)
    • IR-132 LANGTREE RS MW-2D (Quartz diorite well)
  • Site 7: Linville Research Station
  • Site 8: Glen Alpine Research station
    • BK-126 GLEN ALPINE RS (Bedrock well)
    • BK-127 GLEN ALPINE RS(Shallow well)

Research Station Table

Below are the stations where data was recorded.

Research Station AreaStationData type
USGS Research Station at Pleasant Gardens, NC354133082042203 (MC-109)Groundwater (bedrock)
USGS Research Station at Pleasant Gardens, NC354133082042201 (MC-107)Groundwater (regolith)
USGS Research Station at Pleasant Gardens, NC3.54133E+14Raingage
USGS/NCDENR Linville RS near Linville, NC (discontinued)360455081530101 (AV-074)Groundwater (bedrock)
USGS/NCDENR Glen Alpine RS near Morganton, NC354302081433201 (BK-126)Groundwater (bedrock)
USGS/NCDENR Glen Alpine RS near Morganton, NC354302081433202 (BK-127)Groundwater (regolith)
USGS/NCDENR Glen Alpine RS near Morganton, NC3.54302E+14Raingage (discontinued)
USGS Raingage Near Morganton, NC3.54353E+14Raingage
USGS Research Station near Granite Falls, NC355031081243202 (CD-101)Groundwater (transition)
USGS Research Station near Granite Falls, NC355031081243203 (CD-102 )Groundwater (bedrock)
USGS Research Station near Granite Falls, NC3.55031E+14Raingage
USGS Oxford RS Nr Claremont, NC354616081085101 (CW-350)Groundwater (transition)
USGS Oxford RS Nr Claremont, NC354616081085102 (CW-351)Groundwater (bedrock)
USGS Oxford RS Nr Claremont, NC3.54616E+14Raingage
USGS/NCDENR Langtree Penninsula RS near Mooresville, NC353135080524201 (IR-130)Groundwater (regolith)
USGS/NCDENR Langtree Penninsula RS near Mooresville, NC353135080524202 (IR-131)Groundwater (transition)
USGS/NCDENR Langtree Penninsula RS near Mooresville, NC353135080524203 (IR-132)Groundwater (bedrock)
USGS/NCDENR Langtree Penninsula RS near Mooresville, NC3.53135E+14Raingage
USGS/NCDENR Pasour Mountain RS, near Dallas, NC352012081154301 (GS-289)Groundwater (regolith)
USGS/NCDENR Pasour Mountain RS, near Dallas, NC352012081154302 (GS-290)Groundwater (transition)
USGS/NCDENR Pasour Mountain RS, near Dallas, NC3.52012E+14Raingage
USGS York County RS near Rock Hill, SC345830081033101 (YRK-3296)Groundwater (regolith)
USGS York County RS near Rock Hill, SC345830081033100 (YRK-3295)Groundwater (bedrock)
USGS York County RS near Rock Hill, SC3.4583E+14Raingage at YRK-3295
USGS Research Station at Mineral Springs, NC345609080415102 (UN-147)Groundwater (transition)
USGS Research Station at Mineral Springs, NC345609080415103 (UN-148)Groundwater (bedrock)
USGS Research Station at Mineral Springs, NC3.45609E+14Raingage
USGS Lancaster County RS nr Lancaster, SC344333080503600 (LAN-497)Groundwater (regolith)
USGS Lancaster County RS nr Lancaster, SC344333080503601 (LAN-498)Groundwater (bedrock)
USGS Lake Wateree RS near Biddle, SC342440080443900 (KER-433)Groundwater (regolith)
USGS Lake Wateree RS near Biddle, SC342440080443901 (KER-435)Groundwater (bedrock)
USGS Lake Wateree RS near Biddle, SC3.4244E+14Raingage at KER-433