Jackson County Vernal Pools - Mitigation
(1)General Requirements. Mitigation may be accomplished by either permittee responsible mitigation projects or by purchasing credits from an established mitigation bank. Mitigation must be conducted according to the following general requirements:
(a)Out-of-kind mitigation is not allowed for vernal pool impacts;
(b)All mitigation projects must meet the ratios and site suitability criteria described in this section.
(c)Mitigation for vernal pool impacts must consist of either protect and manage or restore and manage, or both. Neither enhancement of existing wetland nor creation of wetlands where they did not previously occur is recognized as suitable mitigation for this GP;
(d)Combination credits may be used only once (for wetlands or ESA species separately or for an impact that requires both types); and
(e)The amount of mitigation required to offset impacts to waters of the state depends on both the mitigation site base ratios and the impact site multipliers, as described in this section.
(2)Mitigation Site Base Ratios. Mitigation site base ratios are used to determine the number of credits generated by each type of mitigation, as follows:
(a)One and one-half acres of wetland protected and managed generates one wetland or combination credit (1.5:1 ratio), and
(b)One acre of wetland restored and managed generates one wetland or combination credit (1:1 ratio).
(3)Impact Site Multiplier. The impact site multiplier determines the number of credits that must be purchased from a bank or generated at a permittee responsible mitigation site to offset impacts associated with a project.
(a)The impact acreage is multiplied by 2 if the project meets both of the following:
(A)The vernal pool function ranking of the impact wetland is less than or equal to the 30th percentile score in the AD Inventory; and
(B)The total vernal pool wetland impact for the project is less than 0.5 acres.
(b)The impact acreage is multiplied by 2.5 if the project meets any one of the following:
(A)The vernal pool function ranking is less than or equal to the 30th percentile score in the AD Inventory and the total impact for the project is more than 0.5 acre of vernal pool wetland;
(B)The vernal pool function ranking is between the 30th and 70th percentile scores in the AD Inventory;
(C)The vernal pool wetland proposed for impact is within a USFWS designated critical habitat unit as shown on the Department Web site; or
(D)The vernal pool wetland proposed for impact is hydrologically contiguous with any VPC of 10-30 acres.
(c)The impact acreage is multiplied by 3 if the project meets any one of the following:
(A)The vernal pool function ranking is equal to or greater than the 70th percentile score in the AD Inventory; or
(B)The vernal pool wetland proposed for impact is hydrologically contiguous with any VPC >30 acres.
(d)For impacts to other waters, the impact acreage is multiplied by 2.
(4)Mitigation Site Suitability Criteria. All of the following criteria must be met for a proposed mitigation site under this GP:
(a)Size. The total effective size of a mitigation site must be at least 70 contiguous acres of VPC. The Department will consider adjacent, permanently protected parcels dedicated to vernal pool conservation as part of the total effective size if they have uninterrupted continuity of soils, water flows, and topography. The Department may determine that smaller parcels (10-70 acres) of VPC may be adequate in isolation if they exist within areas in which surrounding land uses are compatible with long-term VPC habitat conservation;
(b)Buffers. Mitigation sites must include sufficient area to maintain the hydrologic regime, soils, topography, and vegetation conditions to provide suitable habitat for the typical suite of vernal pools species. The mitigation site must include the surrounding upland mounds and adjacent areas adequate to buffer the VPC habitats against effects from adjacent land uses.
(c)Fairy Shrimp Presence. Mitigation sites must demonstrate at least 10 percent occupancy by vernal pool fairy shrimp, unless only restore and manage mitigation is proposed;
(d)Functionality. Mitigation sites must meet the 70th percentile ranking of the function assessment score, unless only restore and manage mitigation is proposed;
(e)Hardpan. All proposed mitigation sites and must have an intact hardpan layer and no activity anticipated that would perforate the hardpan (e.g. utility easement). If the hardpan is perforated within 100 feet of the mitigation site, or if it is anticipated in the future, the area of the mitigation site adversely affected, as determined by the Department, may generate half of the credits otherwise generated per OAR 141-093-0200 (Jackson County Vernal Pools - Mitigation)(2); and
(f)Net gain. Mitigation projects proposed for lands that are already designated for conservation purposes must provide benefits to vernal pool habitats and species above and beyond those resulting from the current conservation status of the lands. For such cases, the number of credits generated will be determined by the Department.
Rule 141-093-0200 — Jackson County Vernal Pools - Mitigation,