Memos and info re wetland buffer

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May 20, 2011 781 Boulder Drive Page 2 of 5 Sec. 78-1605.Wetland buffer areas. (a) This subsection establishes requirements for wetland buffer areas around protected wetlands. Buffer areas are necessary and beneficial to maintain the health of wetlands. Buffer areas protect the edge of wetlands from erosion while filtering sediment, chemicals and other nutrients from runoff that drains into wetlands. Buffer areas can improve the biological diversity and health of a wetland environment while reducing the adverse impacts of human activities. (b) Buffer areas regulated by this section are areas of vegetative cover that are upland of the wetland edge, and that occur in a natural condition or through restoration. Buffer areas consist of shrubbery and trees, native grasses and/or forbs that are not mowed, fertilized or manicured in any manner. Mowing, fertilizing, manicuring, or vegetation removal within a buffer area is not allowed unless the city has issued a permit for such activity in conjunction with an approved buffer management plan. (1) Acceptable buffer areas shall have the following qualities: a. A continuous dense layer of perennial grasses that have been uncultivated or unbroken for at least ten consecutive years, or b. An over story of trees and/or shrubs with at least 80 percent canopy closure that have been uncultivated or unbroken for at least ten consecutive years, or c. A mixture of the plant communities described in a. and b. above, which have been uncultivated or unbroken for at least ten consecutive years. (2) Unacceptable buffer areas have the following qualities, including but not limited to: a. Undesirable plant species (including but not limited to reed canary grass, common buckthorn, purple loosestrife, leafy spurge and noxious weeds), or b. Lacking a layer of organic thatch or duff, or c. Topography which tends to channelize the flow of surface runoff, or d. Is characteristicaliy unlikely to retain nutrients and sediment. (3) Buffer areas which have been broken or cultivated within the past ten consecutive years must be restored to a condition consistent with an acceptable buffer area defined in section 78-1605(b)(1), a restoration or landscape plan must be submitted to the planning director, which restoration shall include, replanting and maintaining according to each of the following guidelines: a. Buffer areas shall be planted with a seed mix containing 100 percent perennial native plant species, except for a one-time planting of an annual nurse or cover crop such as oats or rye. b. The seed mix to be used shall consist of at least 12 pounds pure live seed (PLS) per acre of native prairie grass seed and five pounds PLS per acre of native forbs. Native prairie grass and native forb mixes shall contain no fewer than four and five species respectively. c. The annual nurse or cover crop shall be applied at a rate of 20 pounds per acre. d. Native shrubs and or trees may be used in addition to forbs and grasses. Shrubs shall be distributed so as to provide a natural appearance and shall not be planted in rows.