Volume 2: Draft Gorst Planned Action Environmental Impact Statement

GORST PLANNED ACTION EIS | AFFECTED ENVIRONMENT, SIGNIFICANT IMPACTS, AND MITIGATION MEASURESUnlike Alternative 1, adoption of the Watershed Characterization & Framework Plan would provide a directive forenhancing and protecting water for human use to residents of the UGA. Generally, the Watershed Characterization& Framework Plan would protect the north central portion of the watershed, the tributaries, and the estuary,while allowing for additional growth and development in the south, and southeastern portions of the watershed,subject to existing protection measures and BMPs. The Guiding Principles would direct more specific action thatmay include water quality treatment for new impervious surfaces.Alternative 2 would allow a moderate increase in employment of 606 jobs and a more substantial increase inresidents of 985 persons over the next 20 to30 years that would substantially increase demand for wastewatertreatment. This projected growth is not accounted for in Kitsap County CFP. In general an extension of sewer mainsand improvement to existing pump stations may be required for the proposed Medium Density Residential area inthe mine area. The mine area is currently undeveloped and wastewater system installation is not anticipated todisrupt service in the area. A preliminary analysis of sewer capacity at the mine where approximately 96 acrescurrently used for mineral resources would be converted to Medium Density Residential results in a projectedsanitary flow consistent with the recommended 8-inch diameter system documented in the Kitsap County CFP andcould accommodate the additional residential population at the mine site. In addition, the proposed newresidential area would require developer installed improvements to the wastewater system to accommodate newgrowth.In addition, current deficiencies in stormwater conveyance would be resolved, and standards would be establishedto promote natural stormwater management. Stormwater management on proposed new development andredevelopment would follow the Watershed Characterization & Framework Plan and result in reduced stormwaterrunoff. Proposed LID techniques would reduce flooding problems. Compilation of watershed data and use of thehydrology and hydraulic modeling would also assist in identify priority areas and optimize investment ofstormwater facilities. However, for a conservative analysis in this Draft EIS, a comparison of impervious area showsan increase in impervious area over the Alternative 1 No Action option due to the added development of the minesite. As described, the stormwater standards would be stricter and zero discharge of direct untreated stormwaterwould be allowed, and greater water quality standards would be instituted.The watershed characterization model identifies the Gorst UGA as a restoration and development zone. The modelresults for storage suggest that the mid to lower reaches of Parish Creek and two west of the upper reaches ofGorst Creek are appropriate for urban development involving permanent change in land cover (buildings, roads,sewers). The reclassification of industrial areas to open space/recreation and redevelopment as strictly commercialareas provides an opportunity to improve buffer along the shoreline and set aside areas for stormwaterinfiltration. Potential redevelopment in the low density residential areas also provides opportunities for protectionof critical areas such as the Gorst-Parish floodplain complex and encourages greater floodplain storage which, inturn would reduce stormwater runoff.Overall, Alternative 2 would have a minor effect on utilities from short-term construction related disruptions ofservice and long-term development continued development of high density commercial areas along the shoreline.The long-term effects of the commercial development may be offset by implementation of the adopted WatershedCharacterization & Framework Plan that would ensure stormwater in the watershed would be treated prior todischarge into sensitive waterways or critical areas. The Watershed Characterization & Framework Plan wouldhave a beneficial effect on stormwater management.Alternative 3Under Alternative 3, the Watershed Characterization & Framework Plan would be adopted, along with LID andstormwater standards. Similar to Alternative 2, construction activities associated with Alternative 3 could result inminor short-term disruption of service. Similar to Alternatives 1 and 2, the Gorst UGA would be served by currentwater service providers, which have adequate water source capacity for growth. New development at the minesite would require developer installed improvements for adequate distribution of drinking water. Similar toDraft | June 2013 3-232