LOCATION WALNUT CREEK            NC

Established Series
ARP-EED
06/2025

WALNUT CREEK SERIES

Depth class: Very deep
Drainage class: Well drained
Saturated hydraulic conductivity: Moderately high
Parent material: Human-transported materials over alluvial deposits
Geomorphic location: On filled terraces of floodplains and nearby drainages
Slope range: 0 to 6 percent
Mean annual temperature: 15 degrees C
Mean annual precipitation: 1100 millimeters

TAXONOMIC CLASS:
Coarse-loamy, spolic, mixed, semiactive, nonacid, thermic Anthroportic Udorthents

TYPICAL PEDON:
Walnut creek loam, 2 percent slopes on a filled toe slope in a city business park. When described the soil was moist throughout. (Colors are for moist soil unless otherwise noted.)

^A--0 to 3 centimeters; very dark grayish brown (10YR 3/2), loam; weak granular structure, nonstick, nonplastic; friable; many very fine roots throughout and common fine roots throughout; common fine tubular pores; slightly acid; abrupt smooth boundary. (3 to 24 centimeters thick)

^Bwu--3 to 16 centimeters; yellowish brown (10YR 5/8) loam; moderate thick platy, and weak coarse subangular blocky structure; hard, friable; moderately few medium roots throughout and moderately few fine roots; few fine tubular pores; 20 percent mica flakes; 2 percent persistent gravel sized artifacts of bitumen (asphalt); moderately acid; clear wavy boundary. (0 to 14 centimeters thick)

^C--16 to 85 centimeters; yellowish brown (10YR 5/4); sandy loam; massive; loose, friable, slightly sticky, slightly plastic; few very fine roots throughout and few fine roots throughout; 15 percent fine mica flakes; 3 percent subangular mixed gravels; slightly acid; abrupt wavy boundary.

^Cu--85 to 115 centimeters; brown (10YR 5/3) sandy loam; massive; friable, slightly sticky, slightly plastic; 20 percent fine brown (7.5YR 4/3) relict clay bodies; 2 percent persistent gravel sized artifacts such as glass; slightly acid; abrupt irregular boundary.

^C'--115 to 200 centimeters; reddish brown (2.5YR 5/3) sandy loam; massive, slightly sticky, slightly plastic; 3 percent subangular igneous gravels; slightly acid

TYPE LOCATION:
Wake County, North Carolina; in a developed area on the northeast side of the intersection of Green Road and Leigh Drive.

USGS Quadrangle: East Raleigh, NC
Latitude:35.8531644
Longitude:-78.5886602
Datum: WGS84
Coordinate source: From hand-held GPS

RANGE IN CHARACTERISTICS:
Thickness of human-transported materials: Greater than 50 cm, typically greater than 75 cm
Depth to bedrock: Greater than 150 cm
Depth to seasonal high-water table: Typically, greater than 100 cm; some pedons have a water table within 100 cm.
Artifact content: 0 to 10 percent, by volume
Soil reaction: Slightly acid to neutral throughout
Particle-size control section (weighted average):
Clay content--10 to 18 percent
Sand content--Greater than 40 percent
Rock fragment content--Less than 15 percent
Combined rock and artifact content--0 to 25 percent

^A(u) horizons
Hue--2.5YR to 10YR
Value--2.5 to 4
Chroma--1 to 4
Texture--loam or sandy loam
Rock fragments--0 to 5 percent
Human-Artifacts--0 to 10 percent

^C(u)horizons:
Hue--2.5YR to 10YR,
Value--4 or 5
Chroma--4 to 6
Texture--sandy loam or sandy clay loam
Rock fragments--0 to 8 percent
Human-artifacts: 0 to 10 percent

2Ab horizons (when present):
Hue--10YR
Value 4 or 5,
chroma 1 to 4.
Texture - sandy loam
Rock fragments--0 to 5 percent

2Btb, 2BEb horizons (when present)
Hue--2.5YR to 10YR
Value--5
Chroma-- 6 to 8
Texture--clay loam or sandy clay loam
Rock fragments--0 to 5 percent

2C horizons (when present):
Hue--2.5YR to 7.5YR
Value--5 or 6
Chroma--3 to 8
Texture--coarse sand, loamy sand, or loam
Rock fragments--0 to 15 percent

COMPETING SERIES:
There are no competing series.

GEOGRAPHIC SETTING:
Parent Material: Coarse-loamy human-transported material over alluvium
Landform: Fills, raised land, or other locally raised landforms on floodplains and stream terraces along streams
Slope: 0 to 6 percent
Elevation: 50 to 100 meters
Frost-free period: 200 to 250 days
Mean Annual Air Temperature: 13 to 17 degrees C
Mean Annual Precipitation: 1000 to 1200 mm

GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Appling, Beltline, Cecil, Chavis, Chewacla, Pacolet, Wedowee series,

Appling soils have 35 to 60 precent clay in the particle-size control section; have few to many mica flakes throughout; found on nearby unmodified ridges and sideslopes
Beltline soils have between 25 and 50 centimeters of human-transported material; found on nearby cut and filled ridges and sideslopes
Cecil soils have 35 to 60 precent clay in the particle-size control section and are dominantly 5YR or redder in the argillic horizons; found on nearby unmodified ridges and sideslopes
Chavis soils have 18 to 35 percent clay in the particle-size control section; found on nearby cut and filled ridges and steeper sideslopes
Chewacla soils have aquic conditions; found in nearby drainageways and river valleys
Pacolet soils have 35 to 60 percent clay in the particle-size control section and have few to common mica flakes in the argillic; found on nearby unmodified ridges and sideslopes.
Wedowee soils have 35 to 60 precent clay in the particle-size control section; found on nearby unmodified ridges and sideslopes

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage Class: Well drained
Surface runoff: Low
Saturated Hydraulic Conductivity Class: Typically moderately high except where compacted.
Ponding: None
Flooding: None

USE AND VEGETATION:
Major uses are for residential, commercial, and recreational applications in an urban setting. Vegetation may include managed and unmanaged plant communities with a mix of native and non-native species. Many areas are vegetated with non-native ornamental landscaping and/or turfgrass associated with developed land uses. Some areas may exhibit weedy, invasive, and/or primary succession vegetation communities (e.g., abandoned lots and other unmanaged areas). Some small patches of mixed native forest species such sycamore, river birch, ironwood, and swamp white oak may be present.

DISTRIBUTION AND EXTENT:
Urban and other areas with human-modified landscapes in the South Atlantic and Gulf Slope Cash Crops, Forest, and Livestock Region
Major Land Resource Area; MLRA 136. These soils are of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE:
Raleigh, North Carolina (Special Projects Region)

SERIES ESTABLISHED:
Wake County, North Carolina, 2025

REMARKS:
Typical Pedon Taxonomic Features:
Ochric epipedon--The zone from 0 to 13 centimeters 0 to 5 inches
Human-transported materials--The zone from 0 to 150 centimeters
Particle-size control section--The zone from 25 to 100 centimeters
Taxonomic Version: Keys to Soil Taxonomy, 13th edition (2022)
Other: Walnut Creek name taken from the Walnut Creek Greenway which is a large greenbelt that runs from Lake Johnson Park located in Cary, NC to southeastern Raleigh, NC.
Other: Some pedons may have redoximorphic features below a depth of 100 centimeters in the intact native subsoil and would be included in the concept as related to the thickness of human-transported materials.

Some pedons have a thin subsurface pedogenic horizon (e.g., ^Bw horizon) in the human-transported materials that are typically too thin to qualify for a cambic horizon.

ADDITIONAL DATA:
NASIS User Pedon ID: 2022NC183012

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National Cooperative Soil Survey
U.S.A.