Laserfiche WebLink
River Islands Development at Lathrop January 2021 <br /> Final River Islands Potable Water Technical Report—Rev 3 #6520 <br /> 3 Potable Water Storage Requirements <br /> 3.1 Potable Water Storage Requirements <br /> Per Section 6.2.3 in the City's Water Master Plan, the required PW storage capacity shall include <br /> equalization storage, fire storage and emergency storage. <br /> Equalization storage shall be provided for the purposes accounting for varying water use through the year. <br /> The City's Water System Master Plan recommends an equalization storage volume to be 25% of MDD be <br /> provided, which equates to 1,866,922 gallons. <br /> Emergency storage is required to meet demands during various emergencies, such as natural disasters, <br /> pipeline failures or pump station failure. The City's current emergency storage requirement is 75%of MDD, <br /> which equates to 5,600,765 gallons. <br /> Fire storage requirements are based on storage volumes needed to supply the largest concurrent fire event <br /> (industrial land uses) and a high-density residual fire event within the City for a duration of 2 hours. The <br /> required fire storage volume shall be stored throughout the City's PW distribution system in addition to the <br /> required equalization and emergency storage volumes (Water Master Plan). These two fire flow events <br /> result in in a total City-wide storage requirement of 0.72 MG as shown in Table 3-1. <br /> The final PW storage capacity provided at River Islands will need to include a proportional fire storage <br /> volume based on the developments impact on the City's overall distribution system. Currently this volume <br /> is not known, but the maximum River Islands Fire Storage Capacity Requirement is approximately 0.60 MG <br /> which is equivalent to a simultaneous commercial (largest fire flow requirements in River Islands)and high <br /> density residential fire flow event for a 2-hour duration (see Table 3-1). Prior to the start of the proposed <br /> Phase II BPS and Tank Site, the City will provide the required fire storage capacity requirement to be <br /> included at River Islands. <br /> Table 3-1: City of Lathrop and River Islands Fire Storage Requirements <br /> Volume <br /> Parameter (gallons) <br /> City of Lathrop <br /> Required Industrial Fire Flow Storage Volume' 480,000 <br /> Required High Density Residential Fire Flow Storage Volume 240,000 <br /> Total Required City-Wide Fire Flow Storage Volume 720,000 <br /> River Islands <br /> Required Commercial Fire Flow Storage Volume 360,000 <br /> Required High Density Residential Fire Flow Storage Volume 240,000 <br /> Maximum Required River Islands Fire Flow Storage Volume 600,000 <br /> Notes: <br /> 1. In accordance with the City's Standards, industrial fire events will require a fire flow of 4,000 GPM for a 2-hour <br /> duration. This is equal to 480,000 gallons as shown above. <br /> 2. In accordance with the City's Standards, high density residential fire events will require a fire flow of 2,000 <br /> GPM for a 2-hour duration. This is equal to 240,000 gallons as shown above. <br /> 3. In accordance with the City's Standards, commercial fire events will require a fire flow of 2,000 GPM for a 2- <br /> hour duration. This is equal to 360,000 gallons as shown above. <br /> 13 <br />