Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURESAlternative 2, adoption of the Watershed Characterization & Framework Plan would ensure a directive forenhancing and protect water for human use to residents of the UGA. Alternative 3 supports less job growth at 333jobs, but the highest population growth at 1,082 persons over the next 20 to30 years. Again, this projected growthis not accounted for in Kitsap County CFP. This would substantially increase demand for wastewater treatment, butsimilar to Alternative 2, the current wastewater system has the capacity to accommodate the anticipated growth.Extension of sewer mains and improvement to existing pump stations may be required for the proposedNeighborhood Mixed Use zone in the mine area. A preliminary analysis of sewer capacity at the mine whereapproximately 96 acres currently used for mineral resources would be converted to Neighborhood Mixed Useresults in a projected sanitary flow consistent with the recommended 8-inch diameter system documented in theKitsap County CFP and could accommodate the addition residential population at the mine site. In addition, theproposed new residential area would require developer installed improvements to the wastewater system toaccommodate new growth.Similar to Alternative 2, the watershed characterization model identifies the Gorst UGA as a restoration anddevelopment zone. The reclassification of industrial areas to open space/recreation provides a greater area thanAlternative 2 for stormwater infiltration. The reclassification of commercial areas to mixed used development hasmoderate opportunity to reduce impervious surface and stormwater runoff but greater than Alternative 2.Potential redevelopment across the UGA also provide opportunities for protection critical areas such as the Gorst-Parish floodplain complex and encourage greater floodplain storage and reduce stormwater runoff.Overall, Alternative 3 would have a minor effect on utilities from short-term construction related disruptions ofservice and long-term redevelopment of high density commercial areas with mixed use developments. Thesubstantial increase in residential development and population would affect demand of existing utility services. Acomparison of impervious area shows an increase in impervious area over the Alternative 1 No Action option andslightly more than Alternative 2 due to the added development of the mine site and mixed use areas. As described,the stormwater standards would be stricter, zero discharge of direct untreated stormwater would be allowed, andgreater water quality standards would be instituted. The long-term effects of replacing the existing high densitycommercial developments with a low intensity waterfront along the shoreline and implementation of the adoptedWatershed Characterization & Framework Plan would have a beneficial effect on stormwater management.Mitigation MeasuresSpecific mitigation measures for potential impacts on utilities would be determined during subsequent projectspecificenvironmental review and permitting or through the Planned Action Ordinance. Mitigation includesincorporated plan features, applicable regulations and commitments, and other potential measures.Incorporated Plan FeaturesAll alternatives including the No Action would be subject to NPDES programs and rules. Continued application ofCounty and City NPDES programs and stormwater manuals (which incorporate LID measures) will help reduceimpacts of new development on stormwater.Features of the Gorst Creek Watershed Characterization & Framework Plan and Gorst Subarea Plan that serve asmitigation include the following:• Implement tailored stormwater standards for the Gorst Creek Watershed, including LID standards in areas ofdevelopment, restoration and protection.• Wherever practicable, new development and redevelopment should incorporate LID measures such asinfiltration. Where impractical, stormwater detention may be allowed.• Minimize clearing and promote stormwater management in the upper and middle portions of the watershedto reduce impacts to the lower watershed.Draft | June 2013 3-233