Hugo Neighborhood Association & Historical Society
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Hugo Neighborhood Association & Historical Society |
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SOILS ASSESSMENT Of PROPOSED PIONEER
MEADOWS SUBDIVISION IV.B. Soils 1. 1983 Soil Survey Of Josephine County, Oregon1 The Soil Survey contains information that can be used for soil resource management decisions. It contains information on chemical and physical soil characteristics that will help predict soil behavior for selected land uses. The survey also highlights limitations inherent in the various soil types and discusses improvements needed to overcome the limitations. The original text from the soil survey report of Josephine County, Oregon issued December 1983 has been published on the web. This soil survey is designed for many different users. Farmers, ranchers, foresters, planners, community officials, engineers, developers, builders and home buyers are just a few of the more common users of soil survey information. Many land use decisions such as building site selection, food and fiber production, wildlife management, recreational development, waste disposal, zoning decisions and pollution control are based on soil conditions. Great differences in soil properties such as drainage, flooding, depth to bedrock, shrink and swell potential, soil texture, permeability and rock fragment content can occur within short distances. These and many other soil properties that affect land use are described in the Soil Survey . The location of each soil is shown on the detailed soil maps. Each soil is described and interpretations for specific uses are given. One of the most important parts of the soil survey is the map unit description. These descriptions not only tell what the soil is, and give a full description, but also name other soils that are typically found within the boundaries of the map unit. An important aspect to keep in mind is that up to 20 percent of a mapping unit can be occupied by contrasting soil types. These contrasting soil types are called "inclusions" and usually have different management characteristics. Josephine County is characterized by steep, rugged mountains and narrow river valleys. Elevations range from 750 on the river flood plains to more than 7,000 feet on the higher mountains. The total area of the county is about 1,040,000 acres, of which about 316,000 acres is privately owned and about 724,000 acres is publicly administered. The average annual rainfall ranges from 30 to 80 inches. The climate is warm and dry in the summer and cool and moist in the winter. 2. 2nd & 3rd Order Soil Surveys1 According to the Natural Resources Conservation Service (NRCS), the 1,040,000 acre Josephine County 1983 Soil Survey was mapped at two levels of intensity or detail. The Soil Survey has 157,532 acres (15%) of 2nd order survey, 880,556 acres (85%) of 3rd order survey, and 1,912 acres (0%) of water (Soil Survey - page 13, Table 4, and Index to Map Sheets, Soil Legend).2 Those map unit names with an asterisk were broadly defined units (3rd Order Survey); without asterisk (2nd Order). The more detailed part of the survey would be considered a 2nd order level and the less detailed part would be a 3rd order level. Soil map units in the 2nd order level are identified by field observation and by remotely sensed data. This data is considered intensive and is to be used for general agriculture and urban planning. Map unit size is generally no smaller than 10 acres but could be as small as 4 acres. Soil map units in the 3rd order level usually have less field verification and more remotely sensed data than the 2nd order units. The 3rd order level is considered extensive and can be used for range and community planning. Unit size is generally 40 acres or larger but could be as small as 4 acres. Map scale of the published soil maps is 1:20,000. This scale equates to 1,666.7 feet per inch, 0.6 inches per 1,000 feet, 3.17 inches per mile, or 63.77 acres per square inch. Acreage and proportionate extent of each map unit is given in Table 4 of the Soil Survey. The six soils of the Proposed Pioneer Meadows Subdivision were mapped at a 2nd and 3rd order field observation surveys by the SCS in its 1983 Soil Survey (Soil Survey - page 13, Table 4 and Index to Map Sheets, Soil Legend).
The huge majority of the soils (four out of six) were mapped at a second order survey which account for approximately 76 acres and 77 percent of the subject property. The soils of the lowland meadow area is overwhelming 12B and 18B both of which are second order soil surveys. The 666 acres of 18B Copsey clay is relatively rare in the county and accounts for only 0.1 percent of the land in the county. The forested lands south of the meadow in the Proposed Pioneer Meadows Subdivision are: 42D, 70F, and 71F. The more detailed part of the Soil Survey would be considered a 2nd order level and the less detailed part would be a 3rd order level. Soil map units in the 2nd order level are identified by field observation and by remotely sensed data. This data is considered intensive and is to be used for general agriculture and urban planning (Soil Survey Manual, USDA Handbook No. 18, 1993, page 48, Table 2-1). Map unit size is generally no smaller than 10 acres but could be as small as 4 acres. Soil map units in the 3rd order level usually have less field verification and more remotely sensed data than the 2nd order units. This data is considered extensive and can be used for range and community planning. Unit size is generally 40 acres or larger but could be as small as 4 acres. 3. Soil Conservation Service (SCS)/Natural Resource Conservation Service (NRCS) Soil Report The Proposed Pioneer Meadows Subdivision is located in Hugo, Oregon. It is zoned Woodlot Resource (Map 17). The 1983 SCS Soil Survey identified six soils for the subject property.1
The soils of interest are the Brockman and Copsey meadow soils: 12B, 12D, and 18B, especially 18B. These soils have a second order level survey which were identified by field observation and by remotely sensed data. This data is considered intensive and is to be used for general agriculture and urban planning. Second order intensive surveys are considered reliable, unlike third order surveys. It turns out there is a scientific rationale for the open seasonally wet areas of the old Cochrane ranch. All three of these meadows soils have similar characteristics: they are seasonally wetlands and their properties limit effective rooting depth and plant growth. 18B–Copsey clay has the most serious limitations.1
12B–Brockman.1 The open seasonally wet area is a near match for the Soil Conservation Service’s 1983 description of soil mapping unit 12B–Brockman cobby clay loam, 2 to 7 percent slopes. It was formed in cobby alluvium derived dominantly from serpentinite. The vegetation in areas not cultivated is mainly Jeffrey pine, Douglas-fir, California black oak, whiteleaf manzanita, wedgeleaf ceanothus, and grasses. Typically, the surface lay is dark reddish brown cobby clay loam about 9 inches thick. The subsoil is dark reddish brown cobby clay about 7 inches thick. The upper 18 inches of the substratum is reddish brown cobbly clay. Permeability of this soil is very slow. Available water capacity is about 4 to 8 inches. Water supplying capacity is 10 to 15 inches. Effective rooting depth is limited by a seasonal high water table that is at a depth of 24 to 36 inches in winter and spring. Runoff is medium, and the hazard of water erosion is moderate. The ultramafic rock from which the soil in this unit developed is very high in content of magnesium and very low in calcium, which limits plant growth. The main limitations for pasture are low fertility of the soil, steepness of slope, and the very slow permeability of the substratum. The water table that develops during the rainy period in winter and spring generally limits this unit for deep-rooted crops. Drainage may also be needed. 12D–Brockman.1 The open seasonally wet area is a near match for the Soil Conservation Service’s 1983 description of soil mapping unit 12D–Brockman cobby clay loam, 7 to 20 percent slopes. It was formed in cobby alluvium derived dominantly from serpentinite. The vegetation in areas not cultivated is mainly Jeffrey pine, Douglas-fir, California black oak, whiteleaf manzanita, wedgeleaf ceanothus, and grasses. Typically, the surface layer is dark reddish brown cobby clay loam about 9 inches thick. The subsoil is dark reddish brown cobby clay about 7 inches thick. The upper 18 inches of the substratum is reddish brown cobby clay. Permeability of this soil is very slow. Available water capacity is about 4 to 8 inches. Water supplying capacity is 10 to 15 inches. Effective rooting depth is limited by a seasonal high water table that is at a depth of 24 to 36 inches in winter and spring. Runoff is medium, and the hazard of water erosion is moderate. The ultramafic rock from which the soil in this unit developed is very high in content of magnesium and very low in calcium, which limits plant growth. The main limitations for pasture are low fertility of the soil, steepness of slope, and the very slow permeability of the substratum. The water table that develops during the rainy period in winter and spring generally limits this unit for deep-rooted crops. Drainage may also be needed. 18B–Copsey clay.1 The open seasonally wet area is a near match for the Soil Conservation Service’s 1983 description of soil mapping unit 18B–Copsey clay, 3 to 7 percent slopes. This deep, poorly drained soil is found in drainageways. Typically, the surface layer is black clay about 18 inches thick. Permeability of the soil is very slow. Effective rooting depth is limited by a seasonal high water table that is at a depth of 6 to 18 inches in winter and spring. This soil is subject to rare periods of flooding. The vegetation in most areas is sedges, rushes, and grasses. The production of vegetation is limited by the low fertility of the soil. The ultramafic rock from which the soil is developed is very high in content of magnesium and very low in calcium, which limits plant growth. The main limitations for pasture are low fertility of the soil, excessive wetness, and very slow permeability. The 1983 Soil Survey described meadow soil characteristics can be viewed in the same moisture patterns in aerial photographs in the 1940s and today (Aerial Photo 1; Aerial Photo 2; Aerial Photo 3B). This meadow pasture area, except for fruit tree saplings, has been open and generally free of trees for all the grown life of Mike Walker, especially since 1960 when I-5 was built in northern Josephine County. He would view the area every time he traveled to Grants Pass from Hugo. The significance of the meadow to the establishment and evolution of the Applegate Trail will be addressed in later sections. The expert witness for the applicant provided alternate information about 18B–Copsey clay as identified for the subject property from the 1983 Soil Survey (see Section IV.C.3.).3 The expert witness purported to change the Land Capability Classification (LCC) of 18B from LCC IVw, non-irrigated to LCC VIw. However, the soil descriptions in the 1983 Soil Survey were not challenged with an application for a change to the county’s official soils and wetlands inventories. Therefore, the alternate soils and wetland opinions are a moot point and the hearing body must use the current soils and wetlands inventories in its decision-making. 4. Summary The six soils of the Proposed Pioneer Meadows Subdivision were mapped at a 2nd and 3rd order field observation surveys by the SCS in its 1983 Soil Survey. These soils have a second order level survey which were identified by field observation and by remotely sensed data. This data is considered intensive and is to be used for general agriculture and urban planning. Second order intensive surveys are considered reliable, unlike third order surveys. The soils of interest are the Brockman and Copsey meadow soils: 12B, 12D, and 18B, especially 18B. It turns out there is a scientific rationale for the open seasonally wet meadow areas of the old Cochrane ranch. All three of these meadows soils have similar characteristics: they are seasonally wetlands and their properties limit effective rooting depth and plant growth. 18B–Copsey clay has the most serious limitations. To be accurate on the exact location and extent of the seasonal wetlands, an intensive study by a wetland specialist is needed. However, regardless of any positions pro or con, the merits of any proposed changes can not be decided by the hearing body(s) without an application for a change to the official soils and wetlands inventories; the hearing body must use the current soils and wetlands inventories in its decision-making.
1. United States Department of Agriculture. Soil Conservation Service. December 1983. Soil Survey of Josephine County, Oregon. (0R033) (Now Natural Resources Conservation Service (NRCS). 2. Soil Survey (page 13, Table 4, and Index to Map Sheets, Soil Legend) - those map unit names with an asterisk were narrowly defined units (3rd Order Survey); without asterisk (2nd Order). 3. The Galli Group. August 2006. Subdivision Tentative Plan Application Items Pioneer Meadows Subdivision Grants Pass, Oregon. Section 8.0 Wetlands (page 13); Appendix C. Grants Pass, OR. |
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© 2012 Hugo Neighborhood Association & Historical Society |
