EXHIBIT 99.1

Southwest Water Announces Proposed Public Offering of 1,400,000 Common
                                Shares

    LOS ANGELES--(BUSINESS WIRE)--March 22, 2004--Southwest Water
Company (Nasdaq:SWWC) today announced that it intends to offer to the
public 1,400,000 of its common shares, plus up to an additional
210,000 shares to cover over-allotments, if any, under its shelf
registration statement previously declared effective by the Securities
and Exchange Commission.
    The managing underwriters for the offering are A.G. Edwards &
Sons, Inc. and Janney Montgomery Scott LLC. A copy of the prospectus
supplement and the prospectus related to the offering can be obtained
when available by contacting the local office of either of the
managing underwriters or by contacting A.G. Edwards & Sons, Inc., One
North Jefferson, St. Louis, MO 63103.
    This press release shall not constitute an offer to sell or the
solicitation of an offer to buy, nor shall there be any sale of these
securities in any state in which such offer, solicitation or sale
would be unlawful prior to registration or qualification under the
securities laws of any such state. A registration statement relating
to the shares that the company intends to sell has previously been
filed with, and declared effective by, the Securities and Exchange
Commission.
    Southwest Water Company provides a broad range of services: water
production, treatment and distribution; wastewater collection and
treatment; public works services; utility billing and collection; and
infrastructure construction management. The company owns regulated
public utilities and also serves cities, utility districts and private
companies under contract. More than two million people in 36 states
from coast to coast depend on Southwest Water for high-quality,
reliable service. Additional information may be found on the company's
Web site: www.swwc.com.

    This document contains "forward-looking statements" within the
meaning of the Private Securities Litigation Reform Act of 1995. These
statements involve risks and uncertainties, as well as assumptions
that, if they prove incorrect or never materialize, could cause the
results to differ materially from those expressed or implied by such
forward-looking statements. More detailed information about risk
factors that may affect the company is contained in the company's
filings with the Securities and Exchange Commission, including the
company's 2003 Annual Report on Form 10-K. The company assumes no
obligation to update these forward-looking statements.

    CONTACT: Southwest Water Company
             Richard J. Shields, (213) 929-1800
             www.swwc.com
               or
             PondelWilkinson MS&L
             Cecilia Wilkinson or Robert Jaffe
             (323) 866-6089 or (323) 866-6007
             www.pondel.com