CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER
            PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

                                  EXHIBIT 99.1

I, Anton C. Garnier, President and Chief Executive Officer, certify that:

1.     I have reviewed this annual report on Form 10-K of Southwest Water
       Company;

2.     Based on my knowledge, this annual report does not contain any untrue
       statement of a material fact or omit to state a material fact necessary
       to make the statements made, in light of the circumstances under which
       such statements were made, not misleading with respect to the period
       covered by this annual report;

3.     Based on my knowledge, the financial statements, and other financial
       information included in this annual report, fairly present in all
       material respects the financial condition, results of operations and cash
       flows of the registrant as of, and for, the periods presented in this
       annual report;

4.     The registrant's other certifying officer and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
       we have:

       a)     designed such disclosure controls and procedures to ensure that
              material information relating to the registrant, including its
              consolidated subsidiaries, is made known to us by others within
              those entities, particularly during the period in which this
              annual report is being prepared;

       b)     evaluated the effectiveness of the registrant's disclosure
              controls and procedures as of a date within 90 days prior to the
              filing date of this annual report (the "Evaluation Date");

       c)     presented in this annual report our conclusions about the
              effectiveness of the disclosure controls and procedures based on
              our evaluation as of the Evaluation Date;

5)     The registrant's other certifying officers and I have disclosed, based on
       our most recent evaluation, to the registrant's auditors and the audit
       committee of the registrant's board of directors (or persons performing
       the equivalent function):

       a)     all significant deficiencies in the design or operation of
              internal controls which could adversely affect the registrant's
              ability to record, process, summarize and report financial data
              and have identified for the registrant's auditors any material
              weaknesses in internal controls; and

       b)     any fraud, whether or not material, that involves management or
              other employees who have a significant role in the registrant's
              internal controls; and

The registrant's other certifying officer and I have indicated in this annual
report whether or not there were significant changes in internal controls or
other factors that could significantly affect internal controls subsequent to
the date of our most recent evaluation, including any corrective actions with
regard to significant deficiencies and material weaknesses.

Dated: March 26, 2003                          /s/ ANTON C. GARNIER
                                               --------------------
                                               Anton C. Garnier
                                               Chief Executive Officer