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Appendix_CAppendix C. Alternative 2a (Planned Residential Subdivision) v. Standard Subdivision Impacts Summary Alternative 2a—PRD Impact Summary Standard Subdivision Alternative Impact Summary Comparative Analysis Finding Natural Environment Ground water A series of pipes, swales and basins for treatment and management of surface water are installed to manage stormwater before it reaches the aquifer. No change is anticipated in volumes of water that reach the aquifer via the project site. No impact to the Spokane Rathdrum Prairie aquifer. Water that currently recharges the aquifer would continue to recharge through permeable areas and through the infiltration pond installed at the northern limits of the site. Same treatment and management of surface water before it reaches aquifer as under Alternative 2a. No change in volumes of water that reach the aquifer via the project site are anticipated under the Standard Subdivision Alternative. No impact to the Spokane Rathdrum Prairie aquifer. Water that currently recharges the aquifer would continue to recharge through permeable areas and through the infiltration pond installed at the northern limits of the site. Similar level of impact between Alternative 2a and the Standard Subdivision Alternative. Surface water Addition of culverts and creation of swales and ponds to manage floodwater that enters the site There would be no direct impact to the channel of Chester Creek from the widening of Thorpe Road. Includes 30-acre +/- undeveloped park area in southern portion of the site available to store floodwaters Same addition of culverts and creation of swales and ponds as under Alternative 2a There would be no direct impact to the channel of Chester Creek from the widening of Thorpe Road. No 30-acre park is provided to store floodwaters. Similar level of impact between Alternative 2a and the Standard Subdivision Alternative. Built Environment Land use  42 estate single family residential lots,  206 standard single-family residential lots  52 cottage-style single family residential lots,  228 multi-family residential units,  52 mixed use multi-family residential units integrated with  approximately 13,400 square feet of retail/commercial use,  9,000 square feet of future stand- alone retail commercial use  30% greenspace totaling approximately 30 acres with trails that include a 10-acre park and wildlife travel corridor The southern portion of the site will be filled for residential lots and would not be available to receive floodwater because the park in this area would be omitted from the design—  543-lot subdivision  No new commercial or multifamily residential development  No greenspace or trails The Standard Subdivision Alternative has a greater impact on site land use due to a reduction in open space (30 fewer acres) Flood hazard areas The required loose fill import volume is approximately 377,532 CY 48 on-site acres and 44 off-site acres will be removed from 100-year floodplain Approximately 660,240 CY of fill material would need to be imported under the Standard Subdivision Alternative. Considerably more fill under the Standard Subdivision Alternative Transportation Construction-related truck trips: over a four- year period or approximately 22.47 truck trips per day Alternative 2a is anticipated to generate 380 new AM peak hour trips, with 95 new trips entering the site, and 285 new trips exiting the site via the eight access opportunities previously noted. In the PM peak hour, the project is anticipated to generate 545 new trips, with 338 new trips entering the site, and 207 new trips exiting the site. 5,846 ADT and 545 PM Peak Hour Trips Approximately 40 truck trips (one trip to the site and one return trip) would occur per day over the duration of the site grading activities over a 4-year period. The Standard Subdivision Alternative would require more fill than Alternative 2a, primarily due to the filling of the open space area located just north of East Thorpe Road. The total required fill volume with the Standard Subdivision Alternative is approximately 574,122 CY. 5,529 ADT and 573 PM Peak Hour Trips The Standard Subdivision Alternative generates approximately 317 fewer average daily trips but generates approximately 28 more PM peak hour trips. This is due to the higher PM peak hour trip generation of the single-family residential units and the fact that no internalization trip reduction factor is applied with the Standard Subdivision Alternative because no commercial uses would be included. More construction (fill) generated truck trips under the Standard Subdivision Alternative The Standard Subdivision Alternative generates approximately 317 fewer average daily trips but generates approximately 28 more PM peak hour trips. Environmental Elements Not Analyzed in Detail Air quality Impacts to air quality under the Standard Subdivision Alternative will be similar to those described for Alternative 2a with the following exceptions: The Standard Subdivision Alternative provides a greater number of single-family residences than Alternative 2a, with 543 total single-family residences compared to 300 single family residences in Alternative 2a. The additional single-family residences are more likely to be a source of fine particulates from wood burning stoves. The Standard Subdivision Alternative does not incorporate 30% of the gross site area to public open space, therefore providing less area that can serve as a “carbon sink.” Construction-related impacts to air quality will likely be greater with the Standard Subdivision Alternative The Standard Subdivision Alternative is likely to generate more smoke from wood stoves because it provides more single-family residences. The Standard Subdivision Alternative would also result in greater impacts to air quality from construction-related exhaust. due to the greater degree of imported fill material required. Aesthetics Alternative 2a will convert most of the central, east and northwest areas of the site into a mixed-use community. Remaining areas of the property will be retained as community open space. Most of the field and open space areas on the site would be converted to urban development. The Standard Subdivision Alternative will have somewhat greater impact on local aesthetics Biological Resources The combined buffer impacts equal approximately 15,619 SF. Buffer averaging, and enhancement plantings are proposed to ensure that these impacts do not result in a reduction in the ecological function and values of the riparian area. Fill material placed on the east stream bank will cover an approximately 104,132 SF of area. This area will be replanted with native grasses, trees and shrubs, representing a significant enhancement over existing conditions. The Standard Subdivision Alternative has considerably more impact to critical area buffers Environmental Health Dust, noise, and exhaust from construction Dust, noise, and exhaust from construction Similar level of impact between Alternative 2a and the Standard Subdivision Alternative. Geology Grading may require the movement of up to 450,000 cubic yards of material, with up to 330,000 cubic yards of imported material Due to the placement of fill and site development features proposed under Alternative 2a the opportunity for surface water and precipitation to recharge the underlying aquifer will be limited to the proposed infiltration basin, roadside swales, and dry wells. 574,122 CY of fill material, which will require the import of approximately 660,240 CY of “loose” fill material prior to compaction on the site. Due to the placement of fill and site development features proposed under Alternative 2a the opportunity for surface water and precipitation to recharge the underlying aquifer will be limited to the proposed infiltration basin, roadside swales, and dry wells. Considerably more fill under the Standard Subdivision Alternative Historic, Cultural & Archaeological Essentially no impacts Essentially no impacts Similar level of (non) impact between Alternative 2a and the Standard Subdivision Alternative. Noise During the construction phase noise from construction, land clearing, and fill delivery and placement equipment as well as structure construction will increase for the short term. Following completion of construction, noise will be generated by residential traffic and other residential sources including yard maintenance equipment, domestic pets, occupants, and park use for the long term. The increase in population under the Standard Subdivision Alternative would likely lead to noise levels that are higher than current levels. It is unlikely that the increase would be measurable, but it may be perceived by During the construction phase noise from construction, land clearing, and fill delivery and placement equipment as well as structure construction will increase for the short term. Following completion of construction, noise will be generated by residential traffic and other residential sources including yard maintenance equipment, domestic pets, occupants, and park use for the long term. The increase in population under the Standard Subdivision Alternative would likely lead to noise levels that are higher than current levels. It is unlikely that the increase would be measurable, but it may be Similar level of impact between Alternative 2a and the Standard Subdivision Alternative. residents in terms of the frequency to which they experience noise disturbance. perceived by residents in terms of the frequency to which they experience noise disturbance. Public Services Based on current demographics, it is expected that approximately 1,377 people would reside in the project at full project buildout. Further, it is anticipated that approximately 45 employees would work in the 22,400 SF of new retail space that would result with Alternative The Standard Subdivision Alternative is anticipated to create 543 single-family residential units, which would result in approximately 1,358 new residents at full buildout of the community. Slightly fewer individuals under the Standard Subdivision Alternative but all in Single-family units—more impacts under the Standard Subdivision Alternative due to more single-family units Recreation Alternative 2a is anticipated to generate approximately 300 single-family residential units, 228 multi-family units and 52 mixed-use residential units. Based on the 2013-2017 American Community Survey 5-Year Estimates, it is anticipated that each single-family unit would be occupied by approximately 2.5 residents, and that each of the 280 multi-family units would be occupied by approximately 2.24 residents. This would result in a total population of approximately 1,377 residents upon completion of the project, which is anticipated to occur over a period of approximately 10 years or longer as the housing market dictates. Based on the City’s comprehensive plan level-of- service target of 1.92-acres of park space per 1,000 residents, the project would create demand for approximately 2.64 acres of park space in the community. As noted in the site plan included on Figure 3-15 of this document, Alternative 2a incorporates approximately 30 acres of open space, including a 10-acre park which will fulfill the recreational demands of the new development. The Standard Subdivision Alternative is anticipated to create 543 single-family residential units, which would result in approximately 1,358 new residents at full buildout of the community. Based on the City’s comprehensive plan target of 1.92-acres of parks area per 1,000 residents, the Standard Subdivision Alternative would generate the need for approximately 2.61 acres of park area. The Standard Subdivision Alternative would generate need for park areas that Alternative 2a would not; the Standard Subdivision Alternative would result in greater impact than Alternative 2aa