CHAPTER 9 – Storage Infrastructure
Storage projects help meet the Drinking Water Utility’s Goal 6:
Infrastructure is prudently financed, and sustainably constructed, maintained and operated to ensure reliable delivery of high quality water to a growing community.
The 2015-2020 strategy is to develop and maintain storage and transmission/distribution infrastructure to ensure delivery of water at adequate pressure throughout the system and maintain required fire flow.
Other projects for improving the infrastructure are discussed in Chapter 8 (Source Infrastructure) and Chapter 10 (Transmission/Distribution Infrastructure); Chapter 12 describes operations and maintenance of the infrastructure. Water quality strategies are in Chapter 11.
This chapter describes existing water storage tanks, evaluates their ability to meet current and projected needs, and identifies projects to be constructed in 2015-2020. Washington State Department of Health (DOH) rules on storage facilities are in Chapter 173-160 WAC and Chapter 246-290 WAC, Part 3 (design of public water systems). Detailed specifications are in the DOH Design Manual.
9.1 Description of Existing Storage
The Utility’s system has 11 water storage tanks, with a total capacity of 30.97 million gallons. Table 9.1 is an inventory of these facilities, including capacities, elevations and dimensions. Locations are shown in Chapter 1, Map 1.4. Further details regarding the storage tanks serving each pressure zone are provided below in the analysis section.
9.2 Storage Capacity Analysis
This section reports the analysis of how well existing and planned storage facilities support current and future storage requirements. The design criteria upon which the analysis is based are first presented, followed by a discussion of the evaluation results.
Storage Volume Components
According to DOH requirements, water system storage volume is comprised of five separate components:
• Operating storage
• Equalizing storage
• Fire flow storage
• Standby storage
• Dead storage
These components are illustrated in Figure 9.1.
View Figure 9.1 Storage Components.
|
Meridian No. 1 |
Meridian No. 2 |
Fir 226 (north) |
Fir 226 (south) |
Hoffman 417 |
Boulevard 338 |
Eastside 347 |
Stevens Field 264 |
Bush 298 |
Elliott 298 |
Elliott 380 |
---|---|---|---|---|---|---|---|---|---|---|---|
Zone Served |
|
|
|
|
|
|
|
|
|
|
|
Zone Name |
All Zones |
All Zones |
Zone 226 |
Zone 226 |
Zone 417 |
Zone 338 |
Zone 347 |
Zone 264 |
Zone 298 |
Zone 298 |
Zone 380 |
Elevation Range |
N/A |
N/A |
0 – 139 ft |
0 – 139 ft |
150 – 276 ft |
110 – 205 ft |
110 – 204 ft |
16 – 165ft |
0 – 230 ft |
0 – 230 ft |
0 – 280 ft |
Capacity (mg) |
|
|
|
|
|
|
|
|
|
|
|
Total |
4.0 |
4.00 |
2.50 |
2.50 |
3.69 |
2.44 |
3.43 |
0.60 |
1.05 |
2.00 |
4.76 |
Elevations (ft) |
|
|
|
|
|
|
|
|
|
|
|
Tank Overflow |
301 |
299 |
226 |
226 |
417 |
338 |
347 |
264 |
298 |
298 |
380 |
Tank Floor |
281 |
281 |
206 |
206 |
277 |
238 |
214 |
160 |
258 |
278 |
280 |
Dimensions (ft) |
|
|
|
|
|
|
|
|
|
|
|
Engineering Plans |
Variable |
Variable |
Variable |
Variable |
67-ft Diam. |
66-ft Diam. |
67-ft Diam. |
32 |
67-ft Diam. |
130-ft Diam. |
90-ft Diam. |
Water Depth |
20 |
20 |
20 |
20 |
140 |
95.5 |
130 |
104 |
40 |
20 |
100 |
Construction |
|
|
|
|
|
|
|
|
|
|
|
Year Constructed |
2004 |
1998 |
~1935 |
~1935 |
1980 |
2001 |
1987 |
2007 |
2007 |
1975 |
1994 |
Type |
Ground level |
Ground level |
Buried |
Buried |
Standpipe |
Standpipe |
Standpipe |
Standpipe |
Standpipe |
Buried |
Standpipe |
Material |
Concrete |
Concrete |
Concrete |
Concrete |
Steel |
Steel |
Steel |
Steel |
Steel |
Concrete |
Steel |
Security |
|
|
|
|
|
|
|
|
|
|
|
Enclosed/covered? |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Fenced & locked? |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Yes |
Operating and Dead Storage
Operating storage is the water that lies between low and high water storage elevations set by City operations staff to control system pumps and flow control valves. Dead volume is the volume at the bottom of the tank that cannot be used because it is physically too low to provide sufficient pressures. Operational and dead storage volumes are subtracted from total storage to determine the effective storage available for equalizing, standby and fire flow.
Equalizing Storage
Equalizing storage is the total volume needed to moderate fluctuations in diurnal demands during periods when the demand exceeds the capacity of the supply system. Equalizing storage requirements are greatest during the peak hours of the maximum day demand. Operation of a properly balanced system results in replenishment of storage facilities during times of day when the demand curve is below the capacity of the supply system, and results in withdrawal from storage facilities when the demand exceeds the supply capacity. The equalizing storage of a storage tank must be located at an elevation that provides a minimum pressure of 30 pounds per square inch (psi) to all customers served by the tank.
Fire Flow Storage
Fire flow is defined as either 1,000 gpm for two hours or 4,000 gpm for four hours, depending on the demographics of the zone. The Olympia Fire Department establishes the fire flow needed for each zone. DOH allows for the “nesting” of standby and fire flow storage, with the larger used for the storage volume. However, the Olympia Fire Department requires that both standby and fire flow volumes be provided.
The required fire flow storage for a given pressure zone is calculated as the required fire flow multiplied by the required duration. The fire flow storage required for Zones 417, 338, 226, 264 and 298 is 960,000 gallons, based on a flow rate of 4,000 gpm for a duration of four hours. The fire flow storage required for Zones 347 and 380 is 120,000 gallons, based on a flow rate of 1,000 gpm for a duration of two hours.
The fire flow storage of a tank must be located at an elevation that provides a minimum pressure of 20 psi to all customers served by the tank.
Standby Storage
Standby storage is required to supply reasonable system demands during a foreseeable system emergency or outage. A key concept is that establishing standby storage involves planning for reasonable system outages – those that can be expected to occur under normal operating conditions, such as a pipeline failure, power outage or valve failure. Major system emergencies, such as those created by an earthquake, are intended to be covered by emergency system operations planning, since construction of sufficient reserve volume to accommodate sustained system demands under emergency conditions is not economically feasible.
DOH has established guidelines for determining minimum required standby storage. This component is calculated as the greater of: two times the average day demand, less multi-source credit; or 200 gallons times the number of ERUs served by the storage facility.
The multi-source credit allows the required standby storage to be reduced in pressure zones that have multiple sources of supply. The credit assumes the largest source of supply is out of service. It is calculated as the total source available to a particular pressure zone, or zone combination, less the capacity of the largest source. No credit is allowed for zones having only one source of supply.
DOH recommends that standby storage be located at an elevation that provides a minimum pressure of 20 psi to all customers served by a tank, similar to the fire flow volume requirement.
Evaluation of Storage Capacity
To meet City design standards, storage facilities must be designed so the sum of the required storage for each of the five components is met for the pressure zone(s) that will be served. Detailed results of the storage capacity analysis for each pressure zone are provided below. The minimum required storage for each pressure zone is calculated by adding the five storage components.
In addition to the storage tanks that directly serve the City’s pressure zones, as described in the following subsections, the Meridian Storage Tanks provide supplemental standby storage. However, due to the long 36-inch diameter transmission main that links these storage tanks to the distribution system, the City has elected to focus its standby storage capacity analysis on those storage facilities that directly hydraulically feed a pressure zone and/or are in close proximity to the geographic area covered by the zone.
Map 1.1 in Chapter 1 shows the location of the pressure zones and major drinking water system facilities.
Zones 417 and 338
The storage capacities for Zones 417 and 338 are first analyzed together, since the Hoffman Storage Tank provides storage capacity for both zones. The Boulevard Storage Tank provides additional storage for Zone 338. As a combined system, there is sufficient storage through 2034, as shown in Table 9.2.
Zone 417 must also be analyzed independently, as only the Hoffman Storage Tank provides capacity for this zone. Table 9.3 summarizes the analysis for Zone 417. Currently, with only the Hoffman Storage Tank providing gravity storage to this zone, there is a deficiency of approximately 1.27 million gallons (Mg). To resolve this deficiency, the Utility plans to construct the Log Cabin Storage Tank and have it online in 2016. A new tank with a 90-foot diameter and the same height of the Hoffman Tank (417 feet) would contain approximately 4.5 Mg of storage providing a minimum of 20 psi to all customers within the zone. As a result, storage in this zone would be sufficient through the remainder of the 20-year planning horizon. The gross volume of the new Log Cabin Tank will be about 6.68 MG, including tank wall height that will extend above the overflow elevation.
Zone 347
Storage capacity is provided to Zone 347 by the Eastside Storage Tank. This storage facility provides sufficient capacity throughout the planning period, as shown in Table 9.4.
Zone 264
Zone 264 is primarily supplied by a 10-inch water main, which receives water from the Meridian Storage Tanks. Additional supply is provided by the Capitol Way pressure reducing valve (PRV) that transfers water from Zone 338 and the Boulevard Storage Tank. Additional storage capacity is provided by the Stevens Field Storage Tank, which was constructed in 2007.
As shown in Table 9.5, the total storage capacity is sufficient to meet storage requirements throughout the planning period. The Meridian Storage Tanks and Stevens Field Storage Tank provide storage capacity for operational and equalization purposes. Hydraulic analyses indicate that fire flow storage is utilized equally from the three storage facilities available to the zone: Meridian, Stevens Field, and Boulevard Storage Tanks.
Zone 226, 298 and 380
The storage capacities for Zones 226, 298, and 380 are first analyzed together, due to the interconnectedness of these zones. The Percival Booster Pump Station can supply storage demands from the Fir Street Storage Tanks to Zones 298 and 380 because it is equipped with on-site power. PRVs allow water to be supplied from the Elliott 380 Storage Tank to Zones 298 and 226. The Elliott 298 and Bush Storage Tanks provide additional storage for Zone 298 and through a PRV to Zone 226. As a combined system, there is sufficient storage through 2034, as shown in Table 9.6.
Zone 380 must also be analyzed independently, since only the Elliott 380 Storage Tank provides storage capacity for this zone. Table 9.7 summarizes the analysis for Zone 380, indicating sufficient storage capacity throughout the planning period.
9.3 2015-2020 Storage Infrastructure Projects
The storage projects planned for 2015-2020 will help meet the Drinking Water Utility’s Goal 6:
Infrastructure is prudently financed, and sustainably constructed, maintained and operated to ensure reliable delivery of high quality water to a growing community.
Objective 6.A Design and construct infrastructure to ensure reliable delivery of water.
Storage projects will implement Strategy 6.A.2: Develop and maintain storage and transmission/distribution infrastructure to ensure delivery of water at adequate pressure throughout the system and maintain required fire flow. Chapters 8 and 10 describe source and transmission/distribution infrastructure; Chapter 12 describes operations and maintenance of the infrastructure. Water quality strategies are in Chapter 11.
Based on the analysis in the previous section, the City’s Capital Improvement Program for 2015-2020 includes the following storage projects. Project-level cost estimates and implementation schedule are in Chapter 13, Table 13.2.
• New Log Cabin Storage Tank construction, south of Morse-Merryman Road and east of the Boulevard Storage Tank, to address storage deficiencies in Zone 417.
• Fir Street Storage Tank #1 and #2 seismic retrofit to maintain compliance with seismic codes and to ensure reliability of the facility.
• Elliot Storage Tank seismic retrofit.
• Hoffman Storage Tank Interior Coating. Maintenance to ensure longevity of the tank.
Year |
|||||
---|---|---|---|---|---|
2015 |
2020 |
2034 |
Max (10) |
||
Projected Equivalent Residential Units (ERUs) |
14,500 |
15,825 |
19,976 |
47,415 |
|
Projected Demand(1) |
|
|
|
|
|
Average Day |
2,407,000 |
2,627,000 |
3,316,000 |
7,870,871 |
|
Maximum Day |
4,785,000 |
5,145,000 |
6,226,000 |
15,335,742 |
|
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
|
South Sound Booster (2,350 gpm) |
3,384,000 |
3,384,000 |
3,384,000 |
3,384,000 |
|
Fones Road Booster (1,950 gpm) |
2,808,000 |
2,808,000 |
2,808,000 |
2,808,000 |
|
Shana Well and Corrosion Facility (1,000 gpm) |
1,440,000 |
1,440,000 |
1,440,000 |
1,440,000 |
|
Hoffman Well 3 (S08) (1,000 gpm) |
1,440,000 |
1,440,000 |
1,440,000 |
1,440,000 |
|
Indian Summer Well 20 (S12) (850 gpm) |
1,224,000 |
1,224,000 |
1,224,000 |
1,224,000 |
|
Briggs Well (1,100 gpm) |
0 |
0 |
1,584,000 |
1,584,000 |
|
Total Available Source (gpd) |
10,296,000 |
10,296,000 |
11,880,000 |
11,880,000 |
|
Multi-Source Credit (gpd)(3) |
8,568,000 |
8,568,000 |
10,152,000 |
10,152,000 |
|
Required Storage Calculations |
|
|
|
|
|
Operating Storage (gal)(4) |
448,314 |
448,314 |
448,314 |
448,314 |
|
Equalizing Storage (gal)(5) |
0 |
0 |
0 |
1,396,605 |
|
Standby Storage (gal)(6) |
2,900,000 |
3,165,060 |
3,995,181 |
9,482,977 |
|
Fire Flow Storage (gal)(7) |
960,000 |
960,000 |
960,000 |
960,000 |
|
Required Storage |
|
|
|
|
|
Greater than 30 psi at highest meter (gal)(8) |
448,314 |
448,314 |
448,314 |
1,844,919 |
|
Greater than 20 psi at highest meter (gal)(9) |
4,308,314 |
4,573,375 |
5,403,495 |
12,287,896 |
|
Existing Storage Greater Than 30 psi (gal)(11) |
|
|
|
|
|
Hoffman Storage Tank |
3,692,000 |
3,692,000 |
3,692,000 |
3,692,000 |
|
New Log Cabin Storage Tank |
0 |
6,377,000 |
6,377,000 |
6,377,000 |
|
Boulevard Storage Tank |
1,629,287 |
1,629,287 |
1,629,287 |
1,629,287 |
|
Total Existing Storage at 30 psi (gal) |
5,321,287 |
11,698,287 |
11,698,287 |
11,698,287 |
|
Storage Surplus/(Deficiency) at 30 psi (gal) |
4,872,973 |
11,249,973 |
11,249,973 |
9,853,368 |
|
Existing Storage Greater Than 20 psi (gal) (11) |
|
|
|
|
|
Hoffman Storage Tank |
3,692,000 |
3,692,000 |
3,692,000 |
3,692,000 |
|
New Log Cabin Storage Tank |
0 |
6,377,000 |
6,377,000 |
6,377,000 |
|
Boulevard Storage Tank |
2,218,896 |
2,218,896 |
2,218,896 |
2,218,896 |
|
Total Existing Storage at 20 psi (gal) |
5,910,896 |
12,287,896 |
12,287,896 |
12,287,986 |
|
Storage Surplus/(Deficiency) at 20 psi (gal) |
1,602,582 |
7,714,522 |
6,884,401 |
0 |
|
|
|
Year |
||||
---|---|---|---|---|---|---|
|
|
2015 |
2020 |
2034 |
Max (11) |
|
Projected Equivalent Residential Units (ERUs) |
11,807 |
12,910 |
16,855 |
26,602 |
||
Projected Demand(1) |
|
|
|
|
||
Average Day |
1,960,000 |
2,143,000 |
2,798,000 |
4,415,927 |
||
Maximum Day |
3,897,000 |
4,198,000 |
5,254,000 |
8,489,853 |
||
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
||
South Sound Booster (2,350 gpm) |
3,384,000 |
3,384,000 |
3,384,000 |
3,384,000 |
||
Fones Road Booster (1,950 gpm) |
2,808,000 |
2,808,000 |
2,808,000 |
2,808,000 |
||
Shana Park Well 11 (S10) and Corrosion Facility (1,000 gpm) |
1,440,000 |
1,440,000 |
1,440,000 |
1,440,000 |
||
Hoffman Well 3 (S08) (1,000 gpm) |
1,440,000 |
1,440,000 |
1,440,000 |
1,440,000 |
||
Indian Summer Well 20 (S12) (850 gpm) |
1,224,000 |
1,224,000 |
1,224,000 |
1,224,000 |
||
Briggs Well (1,100 gpm) |
0 |
0 |
1,188,000 |
1,188,000 |
||
Total Available Source (gpd) |
10,296,000 |
10,296,000 |
11,484,000 |
11,484,000 |
||
Multi-Source Credit (gpd)(3) |
8,856,000 |
8,856,000 |
10,044,000 |
10,044,000 |
||
Required Storage Calculations |
|
|
|
|
||
Operating Storage (gal)(4) |
448,314 |
448,314 |
448,314 |
448,314 |
||
Equalizing Storage (gal)(5) |
0 |
0 |
0 |
286,207 |
||
Standby Storage (gal)(6) |
2,361,446 |
2,581,928 |
3,371,084 |
5,320,393 |
||
Fire Flow Storage (gal)(7) |
960,000 |
960,000 |
960,000 |
960,000 |
||
Required Storage |
|
|
|
|
||
Greater than 30 psi at highest meter (gal)(8) |
448,314 |
448,314 |
448,314 |
734,521 |
||
Greater than 20 psi at highest meter (gal)(9) |
3,769,760 |
3,990,242 |
4,779,399 |
7,014,915 |
||
Existing Storage Greater Than 30 psi (gal) |
|
|
|
|
||
Hoffman Storage Tank |
1,892,657 |
1,892,657 |
1,892,657 |
1,892,657 |
||
New Log Cabin Storage Tank |
0 |
3,415,466 |
3,415,466 |
3,415,466 |
||
Total Existing Storage at 30 psi (gal) |
1,892,657 |
5,308,123 |
5,308,123 |
5,308,123 |
||
Storage Surplus/(Deficiency) at 30 psi (gal) |
1,444,343 |
4,859,808 |
4,859,808 |
4,573,602 |
||
Existing Storage Greater Than 20 psi (gal) |
|
|
|
|
||
Hoffman Storage Tank |
2,501,229 |
2,501,229 |
2,501,229 |
2,501,229 |
||
New Log Cabin Storage Tank |
0 |
4,513,686 |
4,513,686 |
4,513,686 |
||
Total Existing Storage at 20 psi (gal) |
2,501,229 |
7,014,915 |
7,014,915 |
7,014,915 |
||
Storage Surplus/(Deficiency) at 20 psi (gal) |
(1,268,531) |
3,024,673 |
2,235,516 |
0 |
||
Year |
|||||
---|---|---|---|---|---|
2015 |
2020 |
2034 |
Max (10) |
||
Projected Equivalent Residential Units (ERUs) |
3,849 |
3,855 |
4,259 |
10,258 |
|
Projected Demand(1) |
|
|
|
|
|
Average Day |
639,000 |
640,000 |
707,000 |
1,702,841 |
|
Maximum Day |
1,271,000 |
1,254,000 |
1,327,000 |
3,318,681 |
|
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
|
Eastside Booster (2,000 gpm) |
2,880,000 |
2,880,000 |
2,880,000 |
2,880,000 |
|
Total Available Source (gpd) |
2,880,000 |
2,880,000 |
2,880,000 |
2,880,000 |
|
Multi-Source Credit (gpd)(3) |
2,880,000 |
2,880,000 |
2,880,000 |
2,880,000 |
|
Required Storage Calculations |
|
|
|
|
|
Operating Storage (gal)(4) |
105,538 |
105,538 |
105,538 |
105,538 |
|
Equalizing Storage (gal)(5) |
0 |
0 |
0 |
278,095 |
|
Standby Storage (gal)(6) |
769,880 |
771,084 |
851,807 |
2,051,615 |
|
Fire Flow Storage (gal)(7) |
120,000 |
120,000 |
120,000 |
120,000 |
|
Required Storage |
|
|
|
|
|
Greater than 30 psi at highest meter (gal)(8) |
105,538 |
105,538 |
105,538 |
383,633 |
|
Greater than 20 psi at highest meter (gal)(9) |
995,418 |
996,623 |
1,077,346 |
2,555,249 |
|
Existing Storage Greater Than 30 psi (gal) |
|
|
|
|
|
Eastside Storage Tank |
1,946,373 |
1,946,373 |
1,946,373 |
1,946,373 |
|
Total Existing Storage at 30 psi (gal) |
1,946,373 |
1,946,373 |
1,946,373 |
1,946,373 |
|
Storage Surplus/(Deficiency) at 30 psi (gal) |
1,840,834 |
1,840,834 |
1,840,834 |
1,562,740 |
|
Existing Storage Greater Than 20 psi (gal) |
|
|
|
|
|
Eastside Storage Tank |
2,555,249 |
2,555,249 |
2,555,249 |
2,555,249 |
|
Total Existing Storage at 20 psi (gal) |
2,555,249 |
2,555,249 |
2,555,249 |
2,555,249 |
|
Storage Surplus/(Deficiency) at 20 psi (gal) |
1,559,831 |
1,558,626 |
1,477,903 |
0 |
|
Year |
|||||
---|---|---|---|---|---|
2015 |
2020 |
2034 |
Max (12) |
||
Projected Equivalent Residential Units (ERUs) |
2,596 |
2,675 |
2,970 |
>2,970 |
|
Projected Demand(1) |
|
|
|
|
|
Average Day |
431,000 |
444,000 |
493,000 |
493,000 |
|
Maximum Day |
859,000 |
869,000 |
926,000 |
926,000 |
|
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
|
10" Water Main (2,545 gpm) |
3,664,800 |
3,664,800 |
3,664,800 |
3,664,800 |
|
1,886,400 |
1,886,400 |
1,886,400 |
1,886,400 |
||
Brewery Well (1,000 gpm) |
0 |
0 |
0 |
0 |
|
Total Available Source (gpd)(3) |
5,551,200 |
5,551,200 |
5,551,200 |
5,551,200 |
|
Multi-Source Credit (gpd) |
3,664,800 |
3,664,800 |
3,664,800 |
3,664,800 |
|
Required Storage Calculations |
|
|
|
|
|
Operating Storage (gal)(4) |
375,000 |
375,000 |
375,000 |
375,000 |
|
Equalizing Storage (gal)(5) |
0 |
0 |
0 |
0 |
|
Standby Storage (gal)(6) |
519,277 |
534,940 |
593,976 |
593,976 |
|
Fire Flow Storage (gal)(7) |
960,000 |
960,000 |
960,000 |
960,000 |
|
Required Storage |
|
|
|
|
|
Greater than 30 psi at highest meter (gal)(8) |
375,000 |
375,000 |
375,000 |
375,000 |
|
Greater than 20 psi at highest meter (gal)(9) |
1,854,277 |
1,869,940 |
1,928,976 |
1,928,976 |
|
Existing Storage Greater Than 30 psi (gal) |
|
|
|
|
|
Stevens Field Storage Tank |
163,489 |
163,489 |
163,489 |
163,489 |
|
Meridian Storage Tanks(10) |
1,508,677 |
1,524,340 |
1,583,376 |
1,583,376 |
|
Total Existing Storage at 30 psi (gal) |
1,672,166 |
1,687,828 |
1,746,864 |
1,746,864 |
|
Storage Surplus/(Deficiency) at 30 psi (gal) |
1,297,166 |
1,312,828 |
1,371,864 |
1,371,864 |
|
Existing Storage Greater Than 20 psi (gal) |
|
|
|
|
|
Stevens Field Storage Tank |
304,882 |
304,882 |
304,882 |
304,882 |
|
Meridian Storage Tanks(10) |
1,508,677 |
1,524,340 |
1,583,376 |
1,583,376 |
|
Boulevard Storage Tank(11) |
316,800 |
316,800 |
316,800 |
316,800 |
|
Total Existing Storage at 20 psi (gal) |
2,130,359 |
2,146,021 |
2,205,058 |
2,205,058 |
|
Storage Surplus/(Deficiency) at 20 psi (gal) |
276,082 |
276,082 |
276,082 |
276,082 |
|
Year |
||||||
---|---|---|---|---|---|---|
2015 |
2020 |
2034 |
Max (10) |
|||
Projected Equivalent Residential Units (ERUs) |
17,500 |
18,867 |
21,675 |
35,244 |
||
Projected Demand(1) |
|
|
|
|
||
Average Day |
2,905,000 |
3,132,000 |
3,598,000 |
5,850,585 |
||
Maximum Day |
5,776,000 |
6,133,000 |
6,755,000 |
11,260,171 |
||
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
||
36" Water Main (4000 gpm) |
5,760,000 |
5,760,000 |
5,760,000 |
5,760,000 |
||
Allison Well 19 (S11) (900 gpm) |
1,296,000 |
1,296,000 |
1,296,000 |
1,296,000 |
||
Allison Well 13 (S09) (650 gpm) |
936,000 |
936,000 |
936,000 |
936,000 |
||
Kaiser Well 1 (S03) (360 gpm) |
518,400 |
0 |
0 |
0 |
||
Indian Springs Well 20 (S12) (850 gpm) |
1,224,000 |
1,224,000 |
1,224,000 |
1,224,000 |
||
Total Available Source (gpd) |
9,734,400 |
9,216,000 |
9,216,000 |
9,216,000 |
||
Multi-Source Credit (gpd)(3) |
3,974,400 |
3,456,000 |
3,456,000 |
3,456,000 |
||
Required Storage Calculations |
|
|
|
|
||
Operating Storage (gal)(4) |
2604,153 |
2604,153 |
2604,153 |
2604,153 |
||
Equalizing Storage (gal)(5) |
0 |
94,481 |
249,815 |
1,000,676 |
||
Standby Storage (gal)(6) |
3,500,000 |
3,773,494 |
4,334,940 |
8,245,171 |
||
Fire Flow Storage (gal)(7) |
960,000 |
960,000 |
960,000 |
960,000 |
||
Required Storage |
|
|
|
|
||
Greater than 30 psi at highest meter (gal)(8) |
2,604,153 |
2,698,634 |
2,853,967 |
3,604,829 |
||
Greater than 20 psi at highest meter (gal)(9) |
7,064,153 |
7,432,128 |
8,148,907 |
12,810,000 |
||
Existing Storage Greater Than 30 psi (gal) |
|
|
|
|
||
Fir 226 (north) |
2,500,000 |
2,500,000 |
2,500,000 |
2,500,000 |
||
Fir 226 (south) |
2,500,000 |
2,500,000 |
2,500,000 |
2,500,000 |
||
Bush 298 |
1,050,000 |
1,050,000 |
1,050,000 |
1,050,000 |
||
Elliott 298 |
2,000,000 |
2,000,000 |
2,000,000 |
2,000,000 |
||
Elliott 380 |
4,760,000 |
4,760,000 |
4,760,000 |
4,760,000 |
||
Total Existing Storage at 30 psi (gal) |
12,810,000 |
12,810,000 |
12,810,000 |
12,810,000 |
||
Storage Surplus/(Deficiency) at 30 psi (gal) |
10,205,847 |
10,111,366 |
9,956,033 |
9,205,171 |
||
Existing Storage Greater Than 20 psi (gal) |
|
|
|
|
||
Fir 226 (north) |
2,500,000 |
2,500,000 |
2,500,000 |
2,500,000 |
||
Fir 226 (south) |
2,500,000 |
2,500,000 |
2,500,000 |
2,500,000 |
||
Bush 298 |
1,050,000 |
1,050,000 |
1,050,000 |
1,050,000 |
||
Elliott 298 |
2,000,000 |
2,000,000 |
2,000,000 |
2,000,000 |
||
Elliott 380 |
4,760,000 |
4,760,000 |
4,760,000 |
4,760,000 |
||
Total Existing Storage at 20 psi (gal) |
12,810,000 |
12,810,000 |
12,810,000 |
12,810,000 |
||
Storage Surplus/(Deficiency) at 20 psi (gal) |
5,745,847 |
5,377,872 |
4,661,093 |
0 |
||
|
|
Year |
|||
---|---|---|---|---|---|
|
|
2015 |
2020 |
2034 |
Max (10) |
Projected Equivalent Residential Units (ERUs) |
4,343 |
4,663 |
5,416 |
9,121 |
|
Projected Demand(1) |
|
|
|
|
|
Average Day |
721,000 |
774,000 |
899,000 |
1,514,150 |
|
Maximum Day |
1,434,000 |
1,516,000 |
1,688,000 |
2,918,300 |
|
Available, Existing + Future Source (gpd)(2) |
|
|
|
|
|
West Bay Booster (2,400 gpm) |
3,456,000 |
3,456,000 |
3,456,000 |
3,456,000 |
|
Elliot Booster Pump Station (2,300 gpm) |
3,312,000 |
3,312,000 |
3,312,000 |
3,312,000 |
|
Total Available Source (gpd) |
6,768,000 |
6,768,000 |
6,768,000 |
6,768,000 |
|
Multi-Source Credit (gpd)(3) |
5,904,000 |
5,904,000 |
5,904,000 |
5,904,000 |
|
Required Storage Calculations |
|
|
|
|
|
Operating Storage (gal)(4) |
618,800 |
618,800 |
618,800 |
618,800 |
|
Equalizing Storage (gal)(5) |
0 |
0 |
0 |
0 |
|
Standby Storage (gal)(6) |
868,675 |
932,530 |
1,083,133 |
1,824,277 |
|
Fire Flow Storage (gal)(7) |
120,000 |
120,000 |
120,000 |
120,000 |
|
Required Storage |
|
|
|
|
|
Greater than 30 psi at highest meter (gal)(8) |
618,800 |
618,800 |
618,800 |
618,800 |
|
Greater than 20 psi at highest meter (gal)(9) |
1,607,475 |
1,671,330 |
1,821,933 |
2,563,077 |
|
Existing Storage Greater Than 30 psi (gal) |
|
|
|
|
|
Elliot 380 Storage Tank |
1,464,615 |
1,464,615 |
1,464,615 |
1,464,615 |
|
Total Existing Storage at 30 psi (gal) |
1,464,615 |
1,464,615 |
1,464,615 |
1,464,615 |
|
Storage Surplus/(Deficiency) at 30 psi (gal) |
845,815 |
845,815 |
845,815 |
845,815 |
|
Existing Storage Greater Than 20 psi (gal) |
|
|
|
|
|
Elliot 380 Storage Tank |
2,563,077 |
2,563,077 |
2,563,077 |
2,563,077 |
|
Total Existing Storage at 20 psi (gal) |
2,563,077 |
2,563,077 |
2,563,077 |
2,563,077 |
|
Storage Surplus/(Deficiency) at 20 psi (gal) |
955,602 |
891,747 |
741,144 |
0 |
|