California Water Service Group
US ˙ NYSE ˙ US1307881029

SecurityCWT / California Water Service Group
InstitutionClean Yield Group
Latest Disclosed Ownership10,135 shares
Latest Disclosed Value $ 459,521
Clean Yield Group reports 7.32% decrease in ownership of CWT / California Water Service Group

On April 14, 2026 - Clean Yield Group filed a 13F-HR form disclosing ownership of 10,135 shares of California Water Service Group (US:CWT) valued at $459,521 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 10,935 shares of California Water Service Group. This represents a change in shares of -7.32% during the quarter. The current value of the position is $453,541 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-04-14 2026-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 10,135 -800 -7.32 460 -2.96 0.1294
2026-01-26 2025-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 10,935 -300 -2.67 474 -8.16 0.1315
2025-10-23 2025-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,235 -250 -2.18 516 -1.34 0.1457
2025-07-17 2025-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,485 0 0.00 522 -6.12 0.1563
2025-04-14 2025-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,485 0 0.00 557 6.92 0.1813
2025-01-13 2024-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,485 0 0.00 521 -16.40 0.1656
2024-10-07 2024-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,485 0 0.00 623 11.87 0.1973
2024-07-10 2024-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,485 -500 -4.17 557 -0.18 0.2080
2024-05-29 2024-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 11,985 -900 -6.98 557 -16.62 0.2167
2024-01-24 2023-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 12,885 0 0.00 668 6.03 0.2815
2023-10-12 2023-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 12,885 0 0.00 630 -5.26 0.2793
2023-07-26 2023-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 12,885 -500 -3.74 665 -14.63 0.2740
2023-04-26 2023-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,385 0 0.00 779 -3.95 0.3318
2023-01-31 2022-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,385 0 0.00 812 15.04 0.3486
2022-10-31 2022-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,385 0 0.00 705 -5.24 0.3272
2022-07-18 2022-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,385 0 0.00 744 -6.18 0.3075
2022-04-25 2022-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,385 -260 -1.91 793 -19.16 0.2801
2022-01-24 2021-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 13,645 -460 -3.26 981 18.05 0.3135
2021-10-27 2021-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 14,105 -20 -0.14 831 5.86 0.2726
2021-07-26 2021-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 14,125 20 0.14 785 -1.26 0.2668
2021-04-26 2021-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 14,105 -1,000 -6.62 795 -2.57 0.2991
2021-01-26 2020-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 15,105 0 0.00 816 24.39 0.2933
2020-10-16 2020-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 15,105 0 0.00 656 -9.02 0.2660
2020-07-22 2020-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 15,105 -1,500 -9.03 721 -13.76 0.3116
2020-04-20 2020-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 16,605 0 0.00 836 -2.34 0.3971
2020-01-17 2019-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 16,605 0 0.00 856 -2.62 0.2683
2019-10-23 2019-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 16,605 0 0.00 879 4.52 0.2899
2019-07-22 2019-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 16,605 -350 -2.06 841 -8.59 0.3040
2019-04-24 2019-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 16,955 -2,040 -10.74 920 1.66 0.3725
2019-01-23 2018-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 18,995 0 0.00 905 11.04 0.3940
2018-10-22 2018-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 18,995 -1,000 -5.00 815 4.62 0.3244
2018-07-24 2018-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 19,995 -1,215 -5.73 779 -1.39 0.3227
2018-04-23 2018-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 21,210 -3,280 -13.39 790 -28.89 0.3336
2018-01-16 2017-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 24,490 -1,350 -5.22 1,111 12.68 0.4398
2017-10-11 2017-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 25,840 0 0.00 986 2.18 0.4022
2017-07-17 2017-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 25,840 -1,730 -6.27 965 -2.33 0.4037
2017-05-03 2017-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 27,570 -9,160 -24.94 988 -20.64 0.4162
2017-01-24 2016-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 36,730 -600 -1.61 1,245 3.92 0.5615
2016-10-28 2016-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 37,330 -1,300 -3.37 1,198 -11.19 0.5207
2016-07-27 2016-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 38,630 -100 -0.26 1,349 26.07 0.5791
2016-04-15 2016-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 38,730 -2,345 -5.71 1,070 9.97 0.4757
2016-01-27 2015-12-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 41,075 -800 -1.91 973 -4.61 0.4801
2015-10-29 2015-09-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 41,875 -520 -1.23 1,020 5.26 0.4810
2015-07-31 2015-06-30 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 42,395 8,245 24.14 969 15.77 0.4452
2015-04-24 2015-03-31 13F CALIFORNIA WTR SVC GROUP COM Stock 130788102 34,150 34,150 0.00 837 0.3588
2015-01-29 2014-12-31 13F California Wtr Svc Group COM 130788102 0 -31,850 -100.00 0 -100.00
2014-10-27 2014-09-30 13F California Wtr Svc Group COM 130788102 31,850 0 0.00 715 -7.26 0.3434
2014-07-21 2014-06-30 13F California Wtr Svc Group COM 130788102 31,850 0 0.00 771 1.18 0.3809
2014-04-24 2014-03-31 13F California Wtr Svc Group COM 130788102 31,850 5,550 21.10 762 25.54 0.3941
2014-01-31 2013-12-31 13F California Wtr Svc Group COM 130788102 26,300 1,900 7.79 607 22.38 0.3249
2013-10-24 2013-09-30 13F California Wtr Svc Group COM 130788102 24,400 0 0.00 496 4.20 0.2686
2013-10-24 2013-06-30 13F California Wtr Svc Group COM 130788102 24,400 24,400 476 0.2721
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.