2014-069 - Final Environmental Impact Report No. 2014-01

Home Browse Search

HARBOR BLVD. MIXED USE TRANSIT CORRIDOR PLAN FINAL FIR CITY OF SANTA ANA 5. Environmental Analysis UTILITIES AND SERVICE SYSTEM demands in the City. This project water demand also represents less than 33 percent of the anticipated 7.7 percent increase in the City's total anticipated demand between 2010 and 2035. Since the City is nearly built out and there are no other currently planned large scale development projects that were not accounted for in the 2010 UWMP, the City will be able to meet the project's water demand. In addition, implementation of the proposed Harbor Corridor Plan would occur in phases so that the increased demand would be a gradual increase over time. According to the City's UWMP, the City has adequate supplies to serve 100 percent of its customers during normal., dry year, and multiple dry year demand through 2035 with projected population increases and accompanying increases in water demand. If MWDOC were to impose Stage 3 water restrictions, the City could anticipate the potential supply shortfall of imported water and would implement its Water Supply Contingency Plan. This would balance demand against reduced supply by imposing water conservation measures and subsequent stages of demand reduction. This WSA concludes that the City will have sufficient water supplies available during normal, single dry, and multiple dry years during a 25 year period to meet all projected water demands associated with its existing and future customers, including the proposed project. In the unlikely event of a water shortage, implementation of the City's Water Supply Contingency Plan and Emergency Water Conservation Plan would ensure that sufficient water supplies were available to serve its customers, including the project and existing and future users. Therefore, the proposed projects impact on water supply is less than significant. Water Conveyance The City of Santa Ana has indicated that while the existing water system adequately meets the current demand and flow requirements, future projects may require upgrades to the existing network Segments that exceed the capacity of the network would be a significant impact. Impact 5.14 -3: Existing and/or proposed storm drainage systems are not adequate to serve the drainage requirements of the proposed project. [Threshold U -3] Impact Analysis: Implementation of the Harbor Corridor Plan would be increase impervious surfaces in the project area through the development of individual project sites. The majority of impervious surfaces would come from development of the existing vacant lots, which make up approximately 11.6 acres of the project area. At project completion, the Harbor Corridor Plan area is estimated to generate 15 percent more runoff than in current conditions (BI 2013). With project drainage volumes were forecast by adding 15 percent to existing estimated drainage volumes. Needed storm drain improvements for project generated drainage were identified by comparing with - project drainage volumes to existing capacities. The Drainage Engineering Report prepared in 1993 by Boyle Engineering has shown that the existing drainage system is deficient and unable to convey the current runoffs. Table 5.14 -11 shows the pipe capacities and deficiencies if the recommendations of the Drainage Engineering Report were implemented and the existing flows were increased by 15 percent to account for the implementation of the proposed project. As shown in the table, after completion of specified drainage improvements, no drainage deficiencies would October 2014 Page 5.14 -17