WATERSHED CONDITIONS: PEE DEE RIVER BASIN Broad Upper Savannah Lynches SANTEE Pee Dee Catawba- Saluda Wateree Little SA Pee Dee V ANN Congaree PEE DEE Waccamaw Black AH Santee Lower Edisto Savannah ACE Ashley- VIRGINI A Cooper Combahee- Coosawhatchie NO RT H C A R OLI NA Pee Dee Santee basin basin SOUTH Savannah CA RO LI NA basin ACE GEORGIA basin South Carolina Water Assessment 5-1 PEE DEE RIVER SUBBASIN Marion, and Cheraw saw population declines of 0.5 to 8.1 percent between 1990 and 2000. The 2005 per capita income in the subbasin counties ranged from a low of $20,005 in Williamsburg County to $30,399 in sixth-ranked Georgetown County. The 2005 per capita income in South Carolina averaged $28,285. Median household income for 1999 ranged from $28,205 in Williamsburg County to $35,312 in Georgetown County, all below the State median household income of $37,082. The 2000 annual-average employment of non- agricultural wage and salary workers in the subbasin’s counties was about 130,000. The distribution by type of employment included management, professional, and related, 26 percent; production, transportation, and materials moving, 25 percent; sales and office, 24 percent; service, 14 percent; and construction, extraction, and maintenance, 11 percent. PEE DEE RIVER SUBBASIN In the sectors of manufacturing, mining, and public utilities, the combined annual product value from the The Pee Dee River subbasin extends from the North subbasin counties exceeded $8 billion in 1997. Major Carolina border southeast to Winyah Bay and encompasses employers in those counties included Sonoco Products, parts of eight South Carolina counties, including most Wellman Incorporated, and Galey and Lord. of Chesterfield, Darlington, Florence, and Marlboro Counties, approximately half of Marion County, and small Agriculture remains important in this section of the parts of Dillon, Georgetown, and Williamsburg Counties State, and crops and livestock have a cash value of more (Figure 5-1). The subbasin area is approximately 2,350 than $325 million. Florence County ranked fifth in the square miles, 7.8 percent of South Carolina’s land area. State for cash-crop and livestock receipts from farm marketing, and Dillon and Darlington Counties ranked DEMOGRAPHICS twelfth and fourteenth, respectively. The delivered value of timber in the subbasin counties ranged from The 2000 subbasin population was estimated at $10 million to $36 million in 2005, when Georgetown, 227,200, which is about 5.7 percent of the State’s total Williamsburg, and Florence Counties ranked fourth, population. By the year 2020 the population in the eighth, and tenth in delivered value (South Carolina subbasin is expected to reach 271,000. The counties Forestry Commission, 2008). expected to exhibit the largest population increases from 2000 to 2025 are Georgetown, with a projected increase of SURFACE WATER 27 percent, and Florence, with an increase of 12 percent. Hydrology The counties in the Pee Dee River subbasin are predominantly rural in character and population. Florence The main stem of the Great Pee Dee River is the County overall is classified as urban, Georgetown County dominant hydrologic feature of the subbasin. This river is classified as rural, and the remaining subbasin counties originates in North Carolina and receives most of its flow are classified as very rural. The major population centers from drainage in North Carolina. (Although its formal in the subbasin are Florence (30,248), Bennettsville name is the Great Pee Dee River, it is often referred to (9,425), Darlington (6,720), Marion (7,622), Hartsville simply as the Pee Dee River and will be referred to as (7,556), and Cheraw (5,524). Bennettsville, Darlington, such herein.) Major tributary streams in South Carolina South Carolina Water Assessment 5-3 Mt Croghan 1 9 1295.9 Pageland Chesterfield Ruby 52 T ho r. m C CHESTERFIELD ps onCheraw 9 GR Cr. EA T MLB-112 Tatum CTF-81 1305 2 CTF-56 ed 1305.61 ook CTF-57 4 Cr Bennettsville MARLBORO Clio Patrick 1 1306 s k e e CTF-211 r DAR-96 C Blenheim 1309 r Cr. MLB-110 Ceda e e Society r h Hill T 5 McBee Lake 1 Robinson DAR-228 401 15 P 1309.1 E 3 E k ac Bl Hartsville DARLINGTON 95 DILLON Darlington D Sellers C E 1311.5 re E ek C a t f i 301 s Je Quinby h ffr 501 ie FLO-473 1309.8 s FLO-128 20 Marion 1310 Florence 76 C reek 1310.1 MARION 52 FLORENCE C r R . I V E FLO-475 R EXPLANATION MRN-77 1310 Active USGS streamflow gaging station 378 MRN-78 1305 Discontinued USGS streamflow gaging station Johnsonville CTF-81 Water-level monitoring well (see Table 5-5) WILLIAMSBURG 1 Lake (see Table 5-2) Hemingway HORRY Pee Dee River subbasin boundary County boundary GEORGETOWN Highway 701 Fall Line State Scenic River Marion Municipality 0 10 20 30 40 miles Figure 5-1. Map of the Pee Dee River subbasin. 5-4 Chapter 5: Watershed Conditions: Pee Dee River Basin include Black Creek, Catfish Creek, Jefferies Creek, Falls Lake, is located about 15 miles upstream from the and Thompson Creek. Black Creek, the largest of these state border. The operation of these reservoirs, primarily tributaries, flows through the more urbanized (Hartsville, for hydroelectric power generation, strongly influences Darlington, Florence) part of the subbasin. Streams in the behavior of the Pee Dee River in South Carolina, the upper part of the subbasin originate in or traverse particularly during periods of low flow. the upper Coastal Plain. Most streams in this subbasin Six U.S. Geological Survey (USGS) streamflow are associated with extensive swamp areas and follow monitoring sites are active within this subbasin, three on indistinct channels that often divide and recombine. the Pee Dee River and three on Black Creek. A gaging A 70-mile segment of the Pee Dee River from the station on the Pee Dee River outside the subbasin near US 378 bridge to Winyah Bay was designated as a State Rockingham, N.C., also provides useful flow data. The Scenic River in 2002. (See the River Conservation section entire period of record on the main stem reflects regulated of Chapter 9, Special Topics.) flows by hydroelectric-power facilities in North Carolina. Black Creek streamflow is affected by two impoundments, Although the Pee Dee River in South Carolina is Lake Robinson and Prestwood Lake. Streamflow statistics free-flowing, in North Carolina it is heavily regulated by for seven active and four discontinued gaging stations are a series of six large reservoirs, the last of which, Blewett presented in Table 5-1. Table 5-1. Selected streamflow characteristics at USGS gaging stations in the Pee Dee River subbasin 90% Minimum Maximum Maximum Gaging station name, Period Drainage Average exceeds daily flow daily flow peak flow location, of area flow flow (cfs), (cfs), (cfs), station number record (mi2) (cfs) (cfsm) (cfs) year year year Pee Dee River 1927 58 242,000 270,000 near Rockingham, N.C. to 6,863 7,903 1.15 1,490 1290 2007* 1951 1945 1945 Whites Creek 1979 0.0 732 911 near Wallace to 26.4 29.2 1.11 4.7 1295.9 1995 1990 1987 1992 Juniper Creek 1940 0.0 3,910 near Cheraw to 64 72.6 1.13 18.0 – – – 1305 1958 1945, 51, 55, 56 1945 Pee Dee River 1990 48 118,000 124,000 near Bennettsville to 7,600 7,456 0.98 1,160 1305.61 2007* 2000 2003 2003 Cedar Creek 1970 8.7 850 1,030 at Society Hill to 58.2 92.8 1.59 32.0 1306 1981 1981 1979 1971 Black Creek 1959 9.7 2,460 4,500 near McBee to 108 150 1.38 44 1309 2007* 2002 1990 1990 Black Creek 1960 6.1 2,890 4,450 near Hartsville to 173 213 1.23 89 1309.1 2007* 2002 1990 1990 Black Creek 2001 48 6,090 6,450 near Quinby to 438 400 0.91 148 1309.8 2007* 2002 2004 2004 Pee Dee River 1938 653 217,000 220,000 at Peedee to 8,830 9,655 1.09 2,810 1310 2007* 2001 1945 1945 Pee Dee River 1996 671 96,600 99,000 below Peedee to 8,850 8,069 0.91 1,720 1310.1 2007* 2001 2003 2003 Catfish Canal 1966 0.0 755 890 at Sellers to 27.4 26.3 0.96 2.0 1311.5 1992 1978 1971 1971 mi2, square miles; cfs, cubic feet per second; cfsm, cubic feet per second per square mile of drainage area 90% exceeds flow: the discharge that has been exceeded 90 percent of the time during the period of record for that gaging station * 2007 is the most recent year for which published data were available when this table was prepared South Carolina Water Assessment 5-5 1309 (unregulated) Where it enters South Carolina from North Carolina, Black Creek near McBee, S.C. the Pee Dee River has an average annual streamflow of 1,000 about 8,000 cfs (cubic feet per second). At Peedee, in 75–100 percentile (high flow) northwestern Marion County, the river has an average 25–75 percentile (normal flow) 0–25 percentile (low flow) annual streamflow of 9,655 cfs and can be expected to be Daily mean flow indicated by orange line at least 2,810 cfs 90 percent of the time. Streamflow in this river is reasonably steady as indicated by the relatively flat flow-duration curve (Figure 5-2). Flow in the upper portion of the Pee Dee River may be quite variable on a weekly basis due to hydropower discharges upstream in North Carolina; however, discharges from hydropower facilities, in addition to ground-water support from the upper Coastal Plain, sustain relatively steady long-term 100 flows.