Draft terrestrial resources biological assessment
Analysis of Effect of the Action
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- 5.1 Direct Effects
- 5.1.1 California / Nevada Vernal Pool Fairy Shrimp
- 5.1.2 Pacific Region Cook’s Lomatium
- 5.1.3 Pacific Region Large-Flowered Woolly Meadowfoam
5.0 Analysis of Effect of the ActionProject impacts include those effects that will manifest themselves immediately, those that will occur later in time, and those that will become notably harmful only when added to the baseline or combined with the impacts of other similar activities (50 C.F.R. § 402.02). This section includes an analysis of the proposed action’s direct, indirect, and cumulative effects on listed species and their critical habitat. The proposed build alternatives are based on preliminary design concepts. A number of assumptions have been made with respect to project design and construction phasing. A range of options are provided for project elements that are preliminary in the design phase. Based on this, the options discussed will be appropriate for the specific project design aspect and meet performance standards associated with regulatory requirements, where such exist. In cases where design is conceptual, conservative estimates of project elements are used to allow evaluation of potential impacts associated with the design criteria and construction techniques. By taking a “worst-case-scenario” approach based on conceptual design criteria, the potential for disclosure of impacts to exceed evaluated activities is minimized. Due to the evolving design of the Project, the original vernal pools surveyed for vernal pool fairy shrimp in 1999 and 2000 are no longer included in the current project study area. As such, no additional surveys for VPFS were conducted as part of the Draft Technical Terrestrial Resources Report prepared by URS (URS 2010c). The summer 2010 field surveys conducted by URS were habitat-based surveys of vernal pool conditions, as opposed to focused surveys for vernal pool fairy shrimp. Landowner access to the majority of the parcels containing vernal pools that would be impacted under the three Design Options was not permitted. Consequently, verification and assessment of most of these complexes relied on off-site observations. The locations and acreage of these vernal pools are based on previously conducted surveys and previously mapped locations. Delineated boundaries have not been reviewed by the DSL and may be subject to change. This approach, developed in cooperation with USFWS, will result in a more conservative calculation of impacts, compared with expected occupancy of habitats within the Project area. Similarly, impacts calculated using USFWS’ methods, as established in the 2011 PBO, will result in mitigation for impacts to all habitats, thereby increasing the acreage and quality of protected VPC habitat within the region. Calculation of mitigation acreage is reliant upon not only overall acres of vernal pool fairy shrimp habitat that are impacted, either directly or indirectly, but also by its relative conservation value (high, medium, or low). Evaluation of vernal pools for conservation value was completed in the Vernal Pool Habitat Assessment report, prepared by URS in November 2010. A mitigation ratio rule has been described in the PBO for estimation of impacts to vernal pool fairy shrimp and suitable habitat. It is assumed that both plant species under consideration in this assessment will also benefit from vernal pool wetland conservation or replacement. Refer to section 6.0 for acreages of impact based upon “worst-case scenario” evaluations. In assessing impacts, both directly and indirectly, to VPCs, the guidelines outlined in the PBO were used, even though this Project does not quality for approval under the PBO due to impacts to VPFS and both flora species. Because VPCs are a distinct community type and vital to the conservation and recovery of the vernal pool fairy shrimp and because of the difficulty in determining actual presence of the species, all VPC habitats are assumed to contain populations of VPFS; consequently impacts to VPC habitat will be used as a surrogate for impacts to VPFS. This assessment will compare both acreage and conservation values for each assessment unit surveyed. For plant species, population areas over suitable habitat units, as described and provided by USFWS, will be evaluated rather than individuals. An estimation of affected individuals will be made, however recent stem counts are unavailable. 5.1 Direct EffectsDirect effects are those impacts that occur at or very close to the time of the action itself. Such impacts are expected where new roadway or pavement areas are proposed, or where construction staging areas and areas of temporary impact exist that may remove areas of suitable habitat or viable populations. For the purposes of this assessment, all areas within the proposed project footprint will be assessed as being directly, permanently impacted, regardless of where and how land disturbance is proposed. Due to the limited nature of the current design, a “worst-case scenario” is being assumed. No enhancements to vernal pool fairy shrimp suitable habitat within the proposed footprint are proposed. However, conservation mitigation, in the form of vernal pool creation or restoration, in the Medford and White City areas, is being planned by ODOT in conjunction with this project The USFWS has provided direction in analysis of direct and indirect effects to VPC (and, in conjunction, VPFS). VPCs are defined in the PBO as wetland pools and all associated uplands within 100-feet from pool edges (USFWS 2011). Specifically for direct effects across VPCs, the PBO indicates where the footprint intersects VPCs, either wholly or partially, the entire VPC is considered directly impacted (ODOT 2011). Based on project elements described under Section 2 of this document, five general pathways have been identified for direct effects: Construction of new roadway areas, staging areas or access areas that would remove viable populations; Construction within habitat units known or suspected to contain ESA-listed species, where construction would alter the habitat unit to the point of negatively impacting any species present; Habitat fragmentation due to physical barriers (new roadways) or disruption of hydrologic connections; Impacts to flora and fauna species based on noise; and, Impacts to DCH. Direct impacts to VP, VPC habitat, individual species, designated CH, and known species populations within each Build Alternative and Design Option are shown in Table 5-1 below. Impacts related to noise on flora and fauna are not anticipated, and therefore were excluded from assessment. Measures to minimize, avoid, or mitigate for these effects are discussed in detail following each evaluated effect.
5.1.1 California / Nevada Vernal Pool Fairy ShrimpAs stated previously in this assessment, vernal pool fairy shrimp are closely associated with vernal pool wetland complexes. As determining which pools contain shrimp and which do not is virtually impossible, USFWS directs agencies to consider all suitable habitat occupied (USFWS 2011). To determine the extent of impacts to suitable vernal pool habitat, ODOT and the USFWS agreed on a method for calculating impacts (both direct and indirect) based upon distance from the proposed action and conservation value of the resource (vernal pool). For the purposes of this assessment, any vernal pools falling within 250-feet from the edge of the project footprint, whether wholly or partially, were evaluated. VPCs completely within the proposed project footprint were considered directly impacted. Because vernal pools are very closely hydrologically connected, any pools that were in part “clipped” by the project footprint were counted as a whole pool also being directly impacted. Indirect impacts are addressed under Section 5.2. A breakdown of habitat value is presented in Table 5-2.
Selection of the Build Alternative would result in direct impacts to approximately 3.8 acres of vernal pools from direct fill and encroachment. A majority of these impacts would include clipping the edges of vernal pools, not bisecting entire, discrete pools. As shown in Table 5-2, the DI Alternative appears to impact a slightly greater amount of acreage, including high value habitat. As stated previously, due to assumed geospatial mapping errors inherent in the vernal pool fairy shrimp DCH digital data, no direct impacts to DCH are anticipated. Extension of the mapped critical habitat across Agate Road is assumed to be a mapping error between the digital data and the georeferencing of the aerial photograph. The direct impacts of the JTA Phase appear to impact a proportionate amount of vernal pool habitat, due to a hydrologically connected pools on the west side of the project area, but occurring on the Airport’s property. This pool alone is approximately three acres in size. According to the USFWS rule for calculating impacts, part of this pool is clipped by the edge of the alignment so the entire pool must be counted. 5.1.2 Pacific Region Cook’s LomatiumCook’s lomatiumis is known to exist within the project footprint in an area along the Medco Haul Road, near Aviation Way and Commerce Drive. USFWS has indicated that a viable population is located within vernal pool wetlands in that area. The proposed project footprint, associated with JTA Phase elements, is proposed to directly impact this population (approximately 3.06 acres, or roughly 60% of the total area). Stem counts have not been updated recently so a precise count of the number of individuals is not known at this time. Due to this direct impact, ODOT and the Services are in further consultation to determine an appropriate, agreeable mitigation strategy that may including harvesting of seeds to populate vernal pool wetlands associated with the vernal pool mitigation complex being created for this project (D. Sharp, personal communication, March 18, 2011). One area of USFWS-identified DCH for Cook’s lomatium is intersected by the southern area of the JTA-Phase. Approximately 4.95 acres of habitat would be impacted and the total habitat area (approximately 17 acres) would be bisected by the new roadway. Another direct impact associated with construction of proposed project elements would be additional fragmentation and subdivision of existing natural vegetation communities within the region. Separating viable populations of flora would inhibit local pollinators from exchanging genetic material, which may stifle growth, potentially turning a viable population into a non-seed bearing group. In addition, landscaping the proposed Project would result in the introduction of new plantings of trees, shrubs, or herbaceous groundcover within the unpaved portions of the footprint. This would effectively convert the completed roadway corridor to a developed urban area land type. 5.1.3 Pacific Region Large-Flowered Woolly MeadowfoamLarge-flowered woolly meadowfoam exists concurrently with Cook’s lomatium in vernal pool wetland complexes within the project action area. There are two viable populations of woolly meadowfoam that would be directly affected by the proposed project footprint. One population coincides with the Cook’s lomatium near the Airport. As shown in Table 5-1, proposed project elements associated with the JTA Phase would directly impact 1.192 acres in this area. A second population is mapped along West Dutton Road. Full build out of the project would directly impact 2.199 acres of habitat and the individuals within. As stated previously, stem counts for these species have not been conducted recently so exact numbers are not available for this assessment. The “worst case” scenario has been calculated using survey data from 1999 and 2007 (MB&G 2000, 2008). No further plant surveys are currently proposed. The full build alternative would impact approximately 13.7 acres of DCH near the existing western terminus of West Dutton Road. ODOT field surveys conducted in 2008 identified three relatively intact vernal pools containing approximately 251 large-flowered woolly meadowfoam individuals (ODOT 2008a). The full build alternative would impact these pools. Direct impacts associated with the construction of proposed project elements would be similar for woolly meadowfoam as for Cook’s lomatium. Fragmentation of vernal pool wetland habitat would potentially isolate viable populations by directly removing vigorous individuals from an area and creating a large distance over which pollinators would have to travel to exchange pollen. In addition, landscaping would result in the introduction of new plantings of trees, shrubs, or herbaceous groundcover within the unpaved portions of the footprint that would effectively converting the completed roadway corridor to a developed urban area land type. Changes in hydrology to the wetland complexes (either addition to or removal of) may affect vigor of existing populations to the point of become non-seed bearing. Directory: HWY62 -> Terrestrial BA Terrestrial BA -> Draft Terrestrial Resources Biological Assessment oregon highway 62 corridor solutions project Download 486.24 Kb. Share with your friends:
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