Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURESImpactsThis Draft EIS evaluates a No Action Alternative and two action alternatives (Alternative 2 and Alternative 3), asdescribed in Chapters 1 and 2. The No Action Alternative provides a future baseline against which to measure bothshort-term and long-term impacts of the action alternatives on water resources.The City of Bremerton is compiling watershed data for models that would identify and prioritize mitigationmeasures that would restore, enhance, and protect water resources and optimize investment in infrastructure.One of these models is a Hydrological Simulation Program-Fortran (HSPF) Model developed for the GorstWatershed and based on current land use conditions. The HSPF Model is described in Section 3.13.3 Water,Wastewater, and Stormwater. Anticipated economic development and population growth in the Gorst Creekwatershed and Gorst UGA may also affect long-term surface water conditions and potentially change peak flowsand volumes. Potential changes to peak flows and volumes for the action alternatives are compared for eachaction alternative relative to the No-Action Alternative.Impacts Common to All AlternativesWatershedUnder all project alternatives and as described in Chapter 2.0 Alternatives, areas planned land uses outside of theGorst UGA but within the watershed would remain the same as in adopted plan. These areas include the City ofBremerton’s CUL and SKIA, the City of Port Orchard’s McCormick Woods, and remaining rural unincorporatedKitsap County lands. In addition, over the next 20 to 30 year jobs would substantially increase from 264 to 2,305primarily due to economic development in the SKIA. The added jobs in the SKIA area would be subject the SKIASubarea Plan. Population growth is projected to increase from 1,810 to 2,659. Population growth would likelyoccur south of SR 3 and east of Parish Creek. Groundwater and the Gorst aquifer would continue to be protected.One area of concern is the Gorst-Parish floodplain complex that is subject to frequent flooding. Anticipatedpopulation growth and subsequent development upstream of this location would likely increase the amount ofuntreated surface water, peak runoff flows, and sedimentation. Flooding in the Gorst-Parish floodplain complexhas been identified as priority and would eventually be addressed. Because economic development and populationgrowth in the watershed would occur under all project alternatives, effect would be similar and considered minorimpacts on water resources.Gorst UGAUnder all alternatives, construction activities within the UGA would have the potential to impact water resourcescaused by site demolition or construction (water turbidity, debris in the water, etc.), similar to those described inSection 3.1 Geology/Soils. Scale and intensity of construction projects may vary slight by alternative anddifferences are described under each alternative. Overall, construction activities would result in short-term minorimpacts on water resources.Alternative 1Under Alternative 1, over the next 20 to 30 years, construction, maintenance, and operational impacts on waterresources would remain consistent with existing conditions, the Gorst Creek Watershed Characterization &Framework Plan would not be adopted, and a planned action would not be adopted for the Gorst UGA. Highdensity commercial areas would continue to impact hydrology and water quality immediately adjacent to GorstCreek and Sinclair Inlet. Under Alternative 1, an increase in 742 jobs and a population growth of 82 persons isexpected to occur over the next 20 to 30 years. Commercial businesses would expand along the highways andthere is a potential for new residential development to occur surrounding the existing mine or west of SamChristopherson Road. Current regulations recognize the adverse effects of improper water resource management,development in the floodplain, and armoring of streambanks and shorelines and generally seek to prevent thesethrough a variety of site design requirements and construction methods. However, the UGA was previouslyDraft | June2013 3-21