Admin Order 58-12-14 - Laserfiche WebLink

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Natural Resource Enhancement The natural resource enhancement and natural resource revegetation project types were combined into one type of improvement "natural resource enhancement ". For earlier basin planning, natural resource enhancement included planting of trees /shrubs only, while natural resource revegetation included general excavation, hydroseeding, planting trees /shrubs, and erosion control. During this review it was determined that it would be unlikely that a capital project would include only tree /shrub planting, and that if the natural resources of an area were designated to be enhanced, that enhancement would likely include some clearing and grubbing, grading, hydroseeding, planting trees /shrubs and erosion control. Clearing and grubbing, and grading were added because it is likely that with most natural resource enhancement projects some clearing and grubbing of invasive vegetation or dead trees would be necessary and that regrading of the top soil would also be necessary. For a strictly natural resource enhancement project (i.e., no channel modifications) it is unlikely that much excavation would be necessary, therefore excavation was removed from the cost estimate. The construction activities /materials that comprise natural resource enhancement now include clearing and grubbing, grading, hydroseeding, planting trees /shrubs, and erosion control. The original basin planning costs for natural resource enhancement and natural resource revegetation were $10 /square yard (SY) and $49 /SY respectively. After combining the two types of projects into one type, natural resource enhancement, the new recommended unit cost is $13 /SY, as presented in the table below. Natural Resource Enhancement Unit Cost Construction Activity/Material Units Unit Costs Units Unit Costs Comments Clearing and Grubbing AC $4,300 SY $0.90 Grading CY $5 SY $5 Assume a maximum depth of 1 foot to be regraded. H droseed AC $3,200 SY $0.66 Trees /Shrubs EA $120/$36 SY $6 Assume trees planted at 20 -foot spacing on- center (O.C.) and shrubs planted at 10 feet O.C. Erosion Control AC $3,800 SY $0.62 Total for Natural Resource Enhancement SY $13 Although the construction activity and material unit costs for clearing and grubbing, hydroseed and erosion control increased, they are being applied on a square yard basis. Therefore, these increases did not have much impact on the unit cost for natural resource enhancement. The greatest factor that led to the decrease in the unit cost for natural resource enhancement is the modification to the quantity of trees /shrubs per square yard. In the calculations for the basin planning costs, the quantity of trees /shrubs was 0.5 each per SY, which corresponds to a tree /shrub planted approximately every 4 feet O.C. During this review, it was determined that a more appropriate spacing for shrubs would be every 8 feet O.C. and every 20 feet O.C. for trees. For example, on a 100 foot long, 25 foot wide buffer the revised spacing would allow for planting of either 12 trees at a unit cost of $120 /tree or 52 shrubs at a unit cost of $36 /shrub, while the original basin planning allowed approximately 139 trees /shrubs to be planted. On a M