HomeMy WebLinkAbout6/15/2021 Item 7b, Floyd/Metz Staff Agenda CorrespondenceCity of San Luis Obispo, Council Memorandum
Council Agenda Correspondence
DATE: June 15, 2021
TO: Mayor and Council
FROM: Aaron Floyd, Utilities Director
Jennifer Metz, Utilities Project Manager
VIA: Derek Johnson, City Manager
SUBJECT: Item 7.b. – 2020 URBAN WATER MANAGEMENT PLAN AND 2020
WATER SHORTAGE CONTINGENCY PLAN
Staff identified a mathematical error in the water demand projection for 2025 in Tables
32, 33, and 34 found in Chapter 6, Water Supply Reliability & Drought Risk Assessment,
of the draft 2020 Urban Water Management Plan (2020 UWMP) and an error in the notes
below each Table. The changes to those are included below in legislative format.
As described in the 2020 UWMP, the City’s water demand projections were derived using
117 gallons per capita per day (gpcd) and on population growth to levels identified in the
City’s General Plan. These factors are higher than current gpcd (94 gpcd in 2020) and
the City’s current population (45,920 in 2020). With these corrections, the City does not
project a water supply shortfall due to conservative water planning.
TABLE 32: Supply and Demand Comparison - Normal Year
2020
(actual) 2025 2030 2035 2040
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166
3,065 2,824 2,396 2,013
NOTES
1. Department of Water Resources, Table 7-2.
2. Units are in acre-feet per year.
3. Water demand projections for 2025 through 2040 were derived using 117 gpcd
and population growth levels identified in the City’s General Plan Land Use
Element. Both factors are higher than the City’s 2020 population and gpcd (92
94 gpcd).
4. Supply total includes the City’s contractual supply to Nacimiento Reservoir,
Safe Annual Yield from Salinas and Whale Rock Reservoirs, and the projected
increase in recycled water deliveries.
Staff Agenda Correspondence for Item 7b Page 2
TABLE 33: Single Dry Year Supply and Demand Comparison
2020
(actual) 2025 2030 2035 2040
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
NOTES
1. Department of Water Resources, Table 7-3.
2. Units are in acre-feet per year.
3. Water demand projections for 2025 through 2040 were derived using
117 gpcd and population growth levels identified in the City’s General
Plan Land Use Element. Both factors are higher than the City’s 2020
population and gpcd (92 94 gpcd).
4. Supply total includes the City’s contractual supply to Nacimiento
Reservoir, Safe Annual Yield from Salinas and Whale Rock
Reservoirs, and the projected increase in recycled water deliveries.
TABLE 34: Multiple Dry Year
Supply and Demand Comparison
2020
(actual) 2025 2030 2035 2040
First year
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
Second year
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
Third year
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
Fourth year
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
Fifth year
Supply totals 10,143 10,337 10,537 10,587 10,637
Demand totals 4,817 7,272 7,713 8,191 8,624
Difference 5,326 3,166 3,065 2,824 2,396 2,013
NOTES
1. Department of Water Resources, Table 7-4.
2. The urban water targets determined in this UWMP were considered when developing the 2020
water demands included in this table.
3. Water demand projections for 2025 through 2040 were derived using 117 gpcd and population growth levels
identified in the City’s General Plan Land Use Element. Both factors are higher than the City’s 2020 population and
gpcd (92 94 gpcd).
4. Supply total includes the City’s contractual supply to Nacimiento Reservoir, Safe Annual Yield from Salinas and
Whale Rock Reservoirs, and the projected increase in recycled water deliveries.