1 Responses to Comments from MSC Members
1. How does the plan protect our 300 acre-feet surface water target from a major canyon fire, where mud and ash could clog our basins and knock the system offline?
To clarify, the UWMP is based on reasonable projections of water supply and demand per State requirements/guidelines and is not necessarily meant to demonstrate how to protect against emergencies such as wildfires. The Water Shortage Contingency Plan, however, outlines how PWP would respond to a significant disruption to the water supply, such as severe droughts/catastrophic emergencies.
The 300 acre-feet per year surface water credit projection is a conservative dry-year yield (versus a target). It is based on PWP’s lowest historical spreading credit since 1975, which occurred in 2015, a historic dry year. This amount is lower than the spreading credits following historical wildfires, such as the Station Fire in 2009 (930 AF total credits in 2010) and the Eaton Fire in 2025 (1,015 AF total credits in 2025).
In addition to the UWMP, PWP continues to work on projects for continued resilience, including the Arroyo Seco Canyon Project that helps further enhance and protect intakes to the spreading grounds, along with other upgrades.
2. Can you provide timelines for the Arroyo Seco Canyon Project, production well replacements, LAG Plant and Monk Hill plume treatment upgrades. What are the milestones we must hit to list them as active in the 2030 UWMP? I think it would be good to come back to MSC with an update on these projects and the total cost, along with what we can do to accelerate them.
Thank you for your help in accelerating these important projects. The following lists the current status on these projects and potential future UWMP integration.
• The Arroyo Seco Canyon Project (ASCP) involves enhancing/expanding the spreading basins and upgrading the existing intake/diversion structure o Spreading basins
Design: Complete
Construction start: end of 2026/early 2027 (pending regulatory permits) Estimated cost: $5 million
o Intake
Design: 90% complete; in review by California Department of Fish & Wildlife
2 Construction start: late summer of 2027/2028 (pending regulatory permits) Estimated cost: $5 million
o Future UWMP integration
Spreading from the ASCP improvements will be reflected in future UWMPs in a normal year supply. It will help boost the spreading credit average for normal years as data is added with time
• Production Wells
o Parke Groundwater Well: Completed in 2025
o Daisy Groundwater Well: Property acquired, in planning phase o Explorer Groundwater Well (see below)
o Future UWMP integration
New production wells/well replacement maintain reliability and resilience of the water system, including helping to maintain groundwater production as currently projected in the UWMP
• Monk Hill Upgrades/Monitoring
o Explorer Well
Below ground improvements: Completed in 2025
Above ground improvements
• Construction start: August 2026
o Both NASA and PWP are monitoring the plume
o Future UWMP integration
Treatment systems help maintain reliability and access to groundwater supplies and maintain groundwater production as currently projected in the UWMP
• Recycled Water and Indirect Potable Reuse
o PWP is working with the cities of Los Angeles and Glendale to develop a new indirect potable reuse project using advanced recycled water treatment at the Los Angeles-Glendale Water Reclamation Plant. The project will enhance supply reliability and will be included in the UWMP after it has been implemented.
3. When successful conservation drops our water sales, how will PWP cover its fixed costs without hitting low-income residents and seniors with higher cost?
This is a key tension facing the water industry today and was a key consideration when designing our current rate structure. Since our utility already recovers a meaningful share of fixed costs through bi-monthly/monthly fixed charges, rather than relying solely on water sales, a drop in consumption does not produce a dollar-for-dollar revenue loss. This 3 provides stability as water use continues to decrease with successful conservation initiatives.
Our tiered rate structure adds another layer of customer agency with essential water use (e.g., indoor) primarily covered by the lowest priced tier, while higher consumption carries progressively higher rates. This means that low-volume users are insulated from upper-tier pricing.
PWP further provides numerous programs to enable customers to further reduce their volumetric usage and therefore their water bill, including direct install programs offered at no cost to the customer. PWP’s direct install programs include the Home Improvement Program, offering installation of water and energy savings measures, such as toilets, showerheads, and irrigation upgrades. Additionally, customers can participate in the direct install Laundry to Landscape Greywater Program, allowing customers to reuse the water from their washing machine in their landscaping. PWP also provides a variety of other rebates/incentives and programs.
4. Why are we so confident that “based on the analyses conducted in this UWMP, PWP anticipates sufficient water supplies to meet its projected demands through 2050? The report raises significant questions about the potential of climate change to increase demands, decrease supply and impose droughts longer than those modeled in the report.
The UWMP requires analysis of water supply reliability in three specific scenarios: normal, single dry, and multiple dry years based on reasonable probable yield and assumptions of growth. PWP’s UWMP analysis of these scenarios demonstrate sufficient water supplies to meet demands through 2050.
At the same time, PWP recognizes that climate change could result in more severe climate extremes. In these conditions outside of the planning framework, the Water Shortage Contingency Plan outlines how PWP would respond to a significant disruption to the water supply, such as during severe droughts/catastrophic emergencies.
The UWMP is intended to be a flexible, long-term planning tool that is updated every five years as new data, climate science, regulations, and state guidance become available.
Additionally, the UWMP must follow guidelines set by the California Department of Water Resources (DWR), along with specific provisions of the California Water Code. DWR publishes a guidebook for every Urban Management Plan that suppliers must respond to and use as a reference for their analysis.
While no long-term planning document can eliminate all uncertainty, PWP is committed to adapting its strategies as conditions change to help ensure continued reliable water service 4 for the community, including infrastructure investments for sustainable water resources as found in PWP’s Water System and Resources Plan.
5. The plan is silent on the fate of our neighboring Altadena water districts. Are we confident they will muddle through their current challenges and not affect our supply/demand? The UWMP includes our interconnections with our neighboring water agencies. However, PWP does not serve as their primary source of supplies. Currently, recovery of neighboring agencies is not anticipated to significantly impact PWP’s water supply and demand balance.
6. How will we address the threat of ammonia-oxidizing bacteria cited on Page 3-9?
PWP addresses the threat of ammonia-oxidizing bacteria (AOB) in our system by continuing to perform weekly and daily compliance monitoring and flushing in conformance to PWP’s state approved Nitrification Plan. Operationally, this includes minimizing detention times and maintaining chlorine/chloramine residuals. In addition, operations like Neutral Output Discharge Elimination System (NO-DES: targeted flushing and sediment removal), dead-end main flushing, and long-term projects like main replacements, are all beneficial in addressing AOB activity and subsequent nitrification.
MWD is also more proactive to nitrification events and has increased chloramine residuals during summer-fall months when chloramine degradation is more noticeable. The past couple years have seen a marked improvement in the levels of nitrification within Pasadena’s distribution system. In combination with operational changes to how water is supplied to different zones in the system, Pasadena currently has its lowest levels of nitrite in the system. Nitrite levels are used as the indicator for AOB activity.
7. What does it mean to say, "Climate change impacts on water demands were not specifically quantified but are accounted for in the annual projections of this UWMP"? If anything the statement seems to be contradicted by the preceding sentence which says they are basing future responses on "historical drought conditions" when the report notes that we are liable to see unprecedented future issues. Page 4-5 Agree that these sentences in the UWMP may be confusing, and we will revise accordingly.
Overall, as noted in the UWMP, climate change is increasing the uncertainty of future water supply and demand. Prolonged droughts, higher temperatures, and other severe weather events could impact groundwater levels, water quality, surface water availability for groundwater recharge, and demand patterns. In response to these challenges, PWP continues to work on projects for continued resilience (e.g., increasing groundwater 5 recharge with capital projects and regional partnerships) and continues to work collaboratively on monitoring and mitigating potential climate change impacts.
8. The report notes that "additional conservations savings will be required in the future to meet the objectives." But this does not appear to be either explicitly quantified — either in total or by conservation measure. I recognize that we can't always differentiate which conservation policy or program directly leads to a customer's reduced use, but do we have any analysis of the specific additional steps we need to take and what each will save? Page 4-6
The conservation standards referenced in the UWMP are part of the Urban Water Use Objectives that retail water suppliers are required to meet, starting in 2025 through 2040.
As part of the UWMP demand projections, PWP calculated the Urban Water Use Objectives based on available data. Comparing the average water use over the last 10 years with the estimated normal year Urban Water Use Objective budgets for the PWP service area, there is a projected annual water savings needed of approximately an additional 600 AF starting in 2035, and another 600 AF (1,200 AF reduction compared to baseline) starting in 2040. These calculated additional annual water savings compared to baseline do not take into consideration the continued rate of reduced water use from existing programs/efforts. In other words, as historical demands show a strong trend of declining water use, it can be anticipated that the trend is likely to continue with continued conservation programs/efforts.
The Urban Water Use Objectives budgets do not have to be met individually, except water loss. Since compliance is based on the entire budget, suppliers can leverage savings in one category to support another, thus achieving compliance. PWP implements a portfolio of water conservation programs designed to encourage customer water-use efficiency behaviors and reduce water use. The portfolio is continually measured for effectiveness, including total participants, costs, and water savings. This portfolio and approach are proven effective with decreasing water use to date. PWP, along with our regional partners, will continue to develop additional strategies for conservation, including new and innovative programs to further meet increasingly stringent water conservation regulations (see the following table).
6 Standard 2025 2028 2029 2030 2035 2040
Indoor Residential 47 GPCD
(Gallons Per
Capita Per Day)
47 GPCD
47 GPCD
42 GPCD
42 GPCD
42 GPCD
Outdoor Residential 0.8 LEF
(Landscape
Efficiency Factor)
0.8 LEF 0.8 LEF
0.8 LEF
0.63 LEF 0.55 LEF
Outdoor Commercial
for Customers with
Dedicated Irrigation
Meters (DIM)
Actual Water
Demand
0.8 LEF 0.8 LEF
0.8 LEF 0.63 LEF
0.45 LEF
Water Loss 28.45 GPSCD
(Gallons Per
Service
Connection Per
Day)
28.45 GPSCD
Standard to be adjusted based on a 3-yr
average
It is important to note that the development of this regulation is relatively new, and budgets are also not fully developed at this time. To calculate the Outdoor Commercial for Customers with DIMs water use budget, landscape area data is needed from the State Water Resources Control Board. This data was only recently provided to PWP and is in the process of being reviewed and categorized. Additionally, PWP has an opportunity to increase the Outdoor Residential Budget as the SWRCB recently provided additional landscape area data. PWP is currently reviewing this data to be returned to the SWRCB.
Understanding the reductions that are needed by 2035 and 2040 will help PWP to evaluate current program offerings and determine where best to invest additional dollars to encourage additional conservation from our customers.
9. The estimate of low-income water use seems poorly thought out. Doesn't research indicate that residential water usage is highly correlated to income? Yet the report estimate 40% of our residential customers are low-income so they must use 40% of the water. Has anyone ever driven through Linda Vista? Page 4-8.
Agree that research shows water usage is correlated to income. The methodology in this UWMP, which is typical in urban water management plans, shows a conservative/higher estimate of lower income household water use. However, to more closely estimate the low- income water use, PWP will revise the UWMP based on the projections in the City’s General Plan Housing Element that approximately 36% (Section 3.3.2.2) of the City’s total households are low‐income. The projections of low‐income households will be multiplied by a per household water-use factor assumed to be 30% lower than system average water use. This assumption is based on a study completed by the California Center for Sustainable Communities at UCLA, which demonstrated that on average, wealthy 7 communities in the Los Angeles area use three times as much water as low-income communities.
10. The audit results that show us out of compliance on "apparent water loss" FY 2025 imply this is due to the Altadena Fire. Were we in compliance prior to that? Page 4-9
Yes, for the past several years we met the state’s standards for both real and apparent loss. Accordingly, we will add a note to the Final UWMP.
11. In very wet years, the report notes, water flows to the ocean can "exceed 40,000 acre feet" — 150% of our 2025 actual water use. Yet it appears the most we've been able to divert is 5,300 acre feet. Later in the report, there are references to plans to expand this, but they don't appear to be quantified. How much more can we expect to recapture in future years either for use, storage or recharge? Page 6-4
To further add context to these numbers, additional information will be added to the UWMP, including the following: “The projected median volume of water to the Devil’s Gate Dam is approximately 2,800 AFY.”
The planned projects are estimated to result in an additional capture and recharge of approximately 1,300 – 1,500 acre-feet per year on average. PWP continues to seek additional capture and recharge opportunities, including partnerships with Metropolitan on additional groundwater programs.
12. The JPL contamination issue is briefly noted on Pages 6-5/6 but tersely says "the extent of plume containment is being monitored." I'm sure that's true, but at least in the last 18 months I'm not aware of any Council or public report on the results of that monitoring.
NASA has 26 monitoring wells throughout Pasadena and performs routine groundwater monitoring. Information on monitoring, including annual reports, can be found on their website: https://jplwater.nasa.gov/. We will include this website link in the UWMP.
13. The report ducks the controversial Delta Diversion project (or whatever euphemism it is currently being called) which may or may not get built and may or may not improve water reliability. One thing everyone seems to agree on is it will be hellishly expensive and if High Speed Rail is any indication, it will exceed the worst fears. Where is PWP on this? Page 6- 6 PWP continues to be in line with Council policy and direction, including the Council resolution recognizing the importance of the Sacramento-San Joaquin Delta to California’s 8 and Pasadena’s water supply and supporting Delta conveyance enhancements as part of a comprehensive approach to ensure California’s water supply remains reliable and sustainable.
Project benefits, costs, and status
The Delta Conveyance Project (DCP) will recover water supply losses caused by climate- driven weather extremes, sea level rise, and earthquakes. Adding new infrastructure will optimize the safe capture and movement of water from big, but infrequent storm events that have become California’s new normal. Currently, the DCP is the only solution to effectively protect the freshwater system in event of an earthquake (according to the United States Geological Survey there is a 72% chance of a 6.7 or greater magnitude earthquake occurring in the Bay Area by 2043 that could cause levees in the Delta to fail, crippling the state’s ability to deliver clean water). Water quality and fisheries remain protected. Water supplies that would otherwise be lost without modernized infrastructure will be restored. If the DCP had been in place over the past five years, California would have captured more than 2.6 million acre-feet of water.
Despite inflation, the Delta Conveyance Design and Construction Authority’s latest cost estimate remains consistent at $20.1 billion, closely aligning with the inflation-adjusted 2020 estimate ($20.2 billion). Further engineering refinements bring this down even more, to $18.9 billion. The DCP is also estimated to be one of the most cost-effective supply alternatives on a dollar per acre-foot basis.
Progress continues with the following completed to date: CEQA, NEPA, California Endangered Species Act (Incidental Take Permit), and Endangered Species Act (BiOp).
Design and engineering also continue to progress.
As the project continues to evolve/be refined, PWP will bring forward for Council discussion should there be significant changes/decision points.
14. Given the strain on current water supply sources, why doesn't the report explore in greater depth the opportunity for water recycling (Page 6-11) and greywater usage (Page 9-7). This is water that doesn't have to be piped from hundreds of miles away.
PWP is working with the cities of Los Angeles and Glendale to develop a new indirect potable reuse project using advanced recycled water treatment at the Los Angeles- Glendale Water Reclamation Plant. The project will improve water supply reliability. As it is still in early discussions among participating agencies, the project is not further described in the 2025 UWMP but will be included in a future UWMP once it has been implemented.
9 Although greywater cannot be used for spray irrigation, PWP offers one of the few greywater programs in the region, by providing a direct install program for laundry to landscape systems that allow customers to reuse the water from their washing machine in their landscaping through drip irrigation. Additionally, PWP provides a rebate to cover permitting fees for residential Simple Greywater Systems, which are systems that use less than 250 gallons per day.
15. The redundant tables of Projected Water Supply through 2050 are all based on formulas, but isn't it misleading to imply that we can accurately estimate water supply and demand to the acre foot (28,371 to be precise)? Wouldn't ~28,000 acknowledge the imprecision inherent in such projections? Page 6-13
Agree. We will look to round where appropriate.
16. The report anticipates droughts of up to five years, based on the "driest year to date with respect to spreading credits being 2014-18. Yet in the last century we've had two Southern California droughts lasting seven years (1928-34; 86-92) and going back further in history, droughts of decades and even centuries have occurred in Southern California — all before climate change. Shouldn't we be more conservative in our planning? Page 7-1
The UWMP requires analysis of water supply reliability in three specific scenarios: normal, single dry, and multiple dry years (five-year drought risk assessment). Although this doesn’t reflect longer drought periods, this is a relatively conservative assessment. For example, the supply assumption (local groundwater spreading credits) used in the five-year drought risk assessment (2014-2018) is significantly lower than historical seven-year droughts.
Additional planning scenarios may be analyzed in other planning documents, such as the Water System and Resources Plan.
17. The report puts great stock in the effectiveness of our Water Waste Prevention Ordinance.
What data do we have on enforcement? Not just on the spot water use incidents, but the mandates for commercial and multifamily customers to install various water saving devices? Page 9-2/3
The multi-family retrofit requirement was mandated by the State during the 2015 drought.
The program was approved by Pasadena City Council on June 1, 2015, with an enforcement deadline of September 1, 2015. Multi-family residential properties were required to self-certify with PWP that the necessary retrofits had been made. Enforcement took place in 2015, 2016, and 2017 to achieve compliance with existing multi-family properties. Any property built after 2017 has these same requirements through the California Green Building Code, so retrofitting is not required. 10 The majority of the water waste is found in outdoor water usage, however the commercial mandates listed in the permanent water waste restrictions can be helpful. For these items, individual enforcement may be less effective than positive reinforcement with commercial customers. PWP continues to work with commercial customers on reducing water waste and promoting water-use efficiency. Commercial is not a one-size-fits-all customer category, requiring specific programming and outreach by customer type. For example, the water savings potential and opportunities within a hotel is different than that of a school, office building, hospital, etc. PWP has a team of Key Account Managers that works with our largest water users to identify water conservation and efficiency opportunities.
18. The most effective residential water saving program (according to the table on 9-8) is turf removal, but the report does not list that as an ongoing program. Why not?
As described in Section 9.7.2 and 9.7.3, all the rebate programs listed in Tables 9-2 and 9- 3 are active and ongoing rebates for residential and commercial customers. The turf removal program is an active program for both residential and commercial customers that has been offered by PWP, in partnership with Metropolitan Water District, for the last 10 years and is expected to continue.
19. The table on 9-8 calculates "Lifetime savings" for various rebates. How many years is that? Is it the same for all of them? Can the chart also reflect annual savings, since annual supply and usage is water is used throughout the rest of the report. I've previously asked about cost-effectiveness. Given the modest amount of participation reflected in the figures, wouldn't we want to double down on the effective ones? Or perhaps do a better job pushing the ones that have fewer than 8 users? And what kind of "tree removal" gets a rebate? Are we trying to remove trees? And if we had eight rebates, how come the lifetime savings is zero?
The “lifetime” differs depending upon the device or rebate, ranging from 5-30 years. These are set in conjunction with MWD based on industry standards.
The lifetime savings is used to reflect the full water savings expected from the device, rebate, or program, especially since device lifetimes vary and the data provided in the UWMP is across multiple years. This approach better supports long-term demand planning, compared to annual savings, which only shows the water-use reduction achieved in the first year that the device was implemented, and does not show the stacked savings every year thereafter throughout the device lifetime.
Regarding cost effectiveness, all the rebates listed in tables 9-2 and 9-3 are offered in partnership with MWD. The rebate amounts reflected in these tables are the combined 11 dollar amount provided by MWD and PWP. PWP conducts full reviews of PWP’s rebates, evaluating them for the following factors:
o The cost effectiveness of the device
o Market cost of the device
o Cost comparison between a rebate eligible device and an ineligible device PWP continually adjusts rebates/programs accordingly. The most current information can be found on PWP’s website and are reflected in SoCal WaterSmart when customers apply for rebates.
The rebates listed in tables 9-2 and 9-3 are developed in conjunction with MWD and the other 25 member agencies, as part of a regional program. All devices are advertised on the PWP’s website; however, marketing and outreach typically focuses on a subset of rebates to ensure customers don’t experience decision fatigue and are able to best understand what program is effective for them. When PWP Water Conservation staff are speaking with residential and commercial customers, they utilize the customers historical water usage, along with basic details about their property or a site visit, to provide tailored recommendations.
Thank you for catching the error in Table 9-2. The program is a “Tree Rebate,” not “Tree Removal.” This is correct in Table 9-3. Table 9-2 will be updated for the final draft.
20. In total the "lifetime" savings from all these programs works out to a little over 4,000 acre feet which is quite impressive, unless it is amortized over ten years or more. Then we are dealing with demand reduction of 400 acre feet a year (or less) which is less than 2% reduction in normal demand. Pages 9-8/9
Tables 9-2 and 9-3 only provide participation data and water savings data for the rebate programs offered in partnership with MWD and does not reflect savings from the additional programs described in section 9.7.1. Additionally, the participation provided in the UWMP is a snapshot in time (5-year period, since the last UWMP) and does not reflect participation in, or continued water savings from, rebate programs prior to 2020. For example, if a customer replaced a toilet in 2010, that device is expected to have a lifespan of 20 years. Since this upgrade was made in 2010, it is not accounted for in the table provided in the UWMP, however, water savings are still being achieved from that installation. PWP continues to track the savings achieved by our water conservation programs. Overall, water use has decreased approximately 30% from the last peak in 1999-2000, despite a population increase over that time.