Res 2016-137/approving a Water Master Plan to guide the future maintenance and extension of the City’s Water Infrastructure

Home Browse Search

Alan Plummer Associates, Inc. Water Master Plan Update 2016 6 With water demand projections complete, hydraulic modeling scenarios could be developed for the average day and maximum day demand cases in each targeted future year. In general, the criteria used to identify the capital improvements needed to serve the projected demand in each target year were as follows: State regulatory criteria met for storage and pumping capacity, Meeting a target pressure of 35 psi during maximum day demand conditions at most points in the distribution system and an absolute minimum of 20 psi (except the suction side of pumps) Headloss rates less than 7 ft. per 1,000 ft. in all pipes, Pipe velocities below 7 ft./s during maximum day demand conditions, Adequate fire flow availability (including 1000 gpm for new connections, 500 gpm for existing connections) under maximum day demand conditions, and Reducing water age where feasible through looped connections. The following sections describe the hydraulic model scenarios developed for each year. 6.1 2020 SYSTEM UPDATES If the rapid growth projected over the next five years comes to pass, particularly the commencement of construction of two very large developments (La Cima and Paso Robles), there will be a significant level of capital improvements necessary to meet all water service criteria. Figure 4-1 showed the location of these two developments in the northwest and western side of the City, respectively. Specifically, the creation of a new pressure plane at an overflow elevation of 1063 feet will be needed to serve the La Cima development (hereafter the 1063 Pressure Plane). The tank should be a 0.5 MG elevated tank, so that portions of the neighboring area can also be connected to the new higher pressure plane and served in the future (Subchapter 6.2). Alternatively, the 1063 Pressure Plane could operate off of a hydropneumatic tank until the elevated tank is built in the 2020 to 2025 time frame. To satisfy state regulatory criteria for this pressure plane, a new pump station at the Ranch Road 12 Tank site (CIP 2b) as well as a new elevated tank (CIP 2a) in the La Cima development will be needed. The La Cima Development Engineering Report has recommended a 300,000 gallon elevated tank to service this area. This would provide only the required storage for the La Cima development itself. Additional pumping capacity at the Comanche PS (CIP 1) will also be required to fill the Ranch Road 12 tank and keep up with the La Cima demands. In order to serve the first phase of the proposed Paso Robles development, the Soyars Pump Station will be reconfigured (CIP 3). The Soyars tank will also be pressure plane. An altitude valve will be installed on the supply side of the tank to keep it from overflowing. The existing line in Hu from the discharge side of the Soyars pump station to provide improved fire flow in this area (CIP 4). 6-1 m:\projects\0600\022-01\doc\report\draft\draftmasterplan-v15_hef.docx