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<br />7A - ATTACHMENT NO.3 <br />Saltworks Proposal- Water Group Summary Report (22 January 2010) Page 15 <br /> <br />This section of the report presents water demand projections for the Saltworks project <br />based on the Attachment Q methodology. This analysis is not the City's Attachment Q <br />analysis for the project. It was carried out based on the land use mix of OMB's <br />application, which has a general description of the types of development within each <br />broad land use classification. These projections were discussed and confirmed with City <br />staff during two meetings (October 19 and November 9, 2009) and subsequent e-mail <br />correspondence. Where the demand projections used for purposes of this report differ <br />from current adopted values in Attachment Q, explanation is provided. <br /> <br />2.3.1 Residential Indoor Demand <br /> <br />Redwood City uses an indoor residential water demand factor of 60 gpcd. This factor is <br />applied to the number of persons per household based on the unit type (single-family, <br />multi-family, high-density). Of the three unit types, the multi-family category at 2.5 <br />persons per unit is most similar to the Saltworks average unit type (2.55 persons per <br />unit). This category also represents the mid-range between the single-family (2.8 <br />persons per household) and high-density (2.2 persons per household) City categories. <br />Therefore, the multi-family unit type at 2.5 persons per household was used for the <br />purposes of the Attachment Q analysis. <br /> <br />The 60 gpcd demand value was adopted by the City as a revision to Attachment Q in <br />June 2007. Prior to this time the residential indoor demand factor was 85 gpcd. The 60 <br />gpcd factor was developed as part of Redwood City's water demand projections required <br />for the SFPUC's Water System Improvement Program in 2006 (WSIP, described further <br />in Section 3.3) and in response to residential water demand research provided in relation <br />to a high-density residential project (Peninsula Park) that was approved by the City in <br />early 2007. <br /> <br />Based on a unit count of 12,000 residential units at 2.5 persons per household (total of <br />30,000 people) at 60 gpcd, the total indoor residential demand for the Saltworks project <br />using the Attachment Q methodology is 2,016 AFY. The City assumes that <br />approximately 19 percent of indoor residential would be served by recycled water for <br />toilet flushing; the remainder would be served by potable water. Thus, the Saltworks <br />project would require 1,633 AFY of potable water and 383 AFY of recycled water for <br />residential indoor uses. <br /> <br />2.3.2 Commercial and Institutional Indoor Demand <br />The non-residential land uses at the Saltworks project fall into the following City <br />Attachment Q categories: Office/Commercial, Restaurants, All Others (which is by type <br />of establishment and includes the community facilities and school uses proposed by the <br />project). The following demand projections for these land uses were used for the <br />Attachment Q analysis: <br /> <br />· Office - 0.06 gallons per square foot per day (gpd/sqft). The current adopted <br />Attachment Q demand factor for office/commercial is 0.13 gpd/sqft. The 0.06 <br />gpd/sqft factor is based on a recently approved WSA (July 2009) for the <br />Stanford in Redwood City project. <br /> <br />· Retail/Restaurant/Community Facilities - 0.55 gpd/sqft. The current adopted <br />Attachment Q demand factors for these land uses vary widely (e.g., gpd/sqft, <br /> <br />8 <br />