Koholalele Hamakua EA PBR Final TMK No. 4-2-005:001

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HAMAIWA LAND SALE: I<OHOLALELE FINAL ENVIRONMENTAL ASSESSMENT Honoka`a Silty Clay Loam, 10 -25% slopes (HTD) constitutes approximately 261 acres or roughly 26 percent of the Site, and is located at the site's highest elevations. The USDA describes this soil as being located on the windward side of Mauna Kea. In a representative profile, the surface layer is dark brown silty clay loam, approximately 6 inches thick. The subsoil is also silty clay loam. It is dark brown, very dark brown, and very dark grayish brown and is approximately 59 inches thick. This soil is medium acid to slightly acid throughout the profile. It dehydrates irreversibly into fine gravel -size aggregates. Permeability is rapid, runoff is slow, and the erosion hazard is slight. Roots can penetrate to a depth of 5 feet or more. This soil is used mostly for pasture and woodland. At the time of the survey, a small acreage at the lowest elevation was used for sugarcane. These soils are in capability Class IV. Honoka`a Silty Clay Loam, Low Elevation, 0 -10% slopes (HsC) constitutes approximately 70 acres or roughly 7 percent of the Koholalele site. This soil is similar to Honoka`a silty clay loam 10 to 25 percent slopes (HTD), except that it occurs at a lower elevation where the soil temperature is warmer. This soil historically has been used principally for sugarcane. Honoka`a Silty Clay Loam, Low Elevation, 10 -20% slopes (HsD) constitutes approximately 343 acres or roughly 33 percent of the Site. This soil is similar to Honoka`a silty clay loam 10 to 25 percent slopes (HTD), except that it occurs at a lower elevation where the soil temperature is warmer. This soil is used historically for sugarcane. Small areas are used for pasture and macadamia nuts. These soils are in Capability Class IV. Honoka`a Silty Clay Loam, Low Elevation, 20 -35% slopes (HsE) constitutes approximately 96 acres or 9 percent of the Site. A band of this soil type runs the length of the site between the 1600 foot and 1700 ground elevation level. This soil is similar to Honoka`a silty clay loam 10 to 20 percent slopes, except that it is steep and occurs at a lower elevation where the soil temperature is warmer. Runoff is medium, and the erosion hazard is moderate. This soil has been used mostly for sugarcane. Small areas are used for pasture and macadamia nuts. These soils are in Capability Class VI. Kuka`iau Silty Clay Loam, 6 -12% slopes (KuC) constitutes approximately 37 acres or 4 percent of the Site. At the site, it is found in the lowest elevations, near Mamalahoa Highway. The USDA describes this soil series as consisting of well- drained silty clay loams that formed in volcanic ash. These soils are gently sloping to steep. They are on uplands at an elevation ranging from 500 to 1,500 feet and receive from 70 to 100 inches of rainfall annually. Their mean annual soil temperature is between 67° and 69° F. The natural vegetation consists of hilograss, kaimi clover, guava, and `ohi`a. These soils and Honoka`a, `0'6kala, and Pa`auhau soils are in the same general area. Historically, Kuka`iau soils are used mostly for sugarcane. Small areas are used for truck crops, macadamia nuts, and pasture. Kuka`iau Silty Clay Loam, 12 -20% slopes (KuD) constitutes approximately 37 acres or 4 percent of the Site. This soil is low on the windward side of Mauna Kea. It is dissected by many, deep, narrow gulches. In a representative profile the surface layer is very dark grayish -brown silty clay loam about 10 inches thick. The subsoil is dark -brown silty clay loam about 40 inches thick. It is underlain by basalt. The surface layer is extremely acid, and the subsoil is medium to slightly acid. This soil dehydrates irreversibly into aggregates the size of fine sand. This soil is similar to Kuka`iau silty clay loam, 6 to 12 percent slopes, except for the steeper slopes. Runoff is medium and the erosion hazard is moderate. 3 -7