Current through Register Vol. 63, No. 9, September 1, 2024
(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(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.
Statutory/Other Authority: ORS 196.600 - 196.692 &
196.795 - 196.990
Statutes/Other Implemented: ORS 196.600 - 196.692 &
196.795 - 196.990