<PAGE>

                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549

                                   FORM 10-Q

(Mark One)

      X  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     ---
     EXCHANGE ACT OF 1934

     For the quarterly period ended June 30, 1999

                                       OR

     ___ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF  1934

     For the transition period from________________ to________________

Commission file number:  0-8176



[LOGO]                      Southwest Water Company
            (Exact name of registrant as specified in its charter)


               Delaware                              95-1840947
    (State or other jurisdiction of               (I.R.S. Employer
     incorporation or organization)              Identification No.)


  225 North Barranca Avenue, Suite 200
        West Covina, California                       91791-1605
(Address of principal executive offices)              (Zip Code)


                                (626) 915-1551
             (Registrant's telephone number, including area code)

     Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes X    No___
                                              ---

     Indicate the number of shares outstanding of each of the issuer's classes
of common stock, as of the latest practicable date.  On August 12, 1999, there
were 4,276,675 common shares outstanding.
<PAGE>

                    SOUTHWEST WATER COMPANY AND SUBSIDIARIES

                                     INDEX
<TABLE>
<CAPTION>
Part I.     Financial Information:                                       Page No.
-------     ----------------------                                       --------
<S>                                                                        <C>

Item 1.     Financial Statements:

            Condensed Consolidated Statements of Income -
            Three and Six months ended June 30, 1999 and 1998                   1

            Condensed Consolidated Balance Sheets -
            June 30, 1999 and December 31, 1998                                 2

            Condensed Consolidated Statements of Cash Flows -
            Six months ended June 30, 1999 and 1998                             3

            Notes to Condensed Consolidated Financial Statements            4 - 5

Item 2.     Management's Discussion and Analysis of
            Financial Condition and Results of Operations                  6 - 10

Part II.    Other Information:
--------    ------------------

Item 1.     Legal Proceedings                                              11- 12

Item 4.     Submission of Matters to a Vote of Security Holders                12

Item 6.     Exhibits and Reports on Form 8-K                                   13

            Signatures                                                         14
</TABLE>
<PAGE>

                   Southwest Water Company and Subsidiaries
                  CONDENSED CONSOLIDATED STATEMENTS OF INCOME
                                  (Unaudited)
<TABLE>
<CAPTION>

                                                      Three Months Ended                Six Months Ended
                                                           June 30,                          June 30,
-------------------------------------------------------------------------------------------------------------
                                                      1999          1998               1999          1998
-------------------------------------------------------------------------------------------------------------
<S>                                                   <C>           <C>               <C>           <C>
                                                                (in thousands except per share data)
Operating Revenues                                   $19,454       $18,332            $36,103       $34,278

Operating Expenses:
Direct operating expenses                             14,038        13,268             26,574        25,427
Selling, general and administrative                    2,845         2,880              5,779         5,645
-------------------------------------------------------------------------------------------------------------
                                                      16,883        16,148             32,353        31,072

Operating Income                                       2,571         2,184              3,750         3,206
Other Income (Expense):
Interest expense                                        (747)         (766)            (1,506)       (1,584)
Interest income                                           19            21                 36            38
Other                                                    100           104                252           187
-------------------------------------------------------------------------------------------------------------
                                                        (628)         (641)            (1,218)       (1,359)

Income Before Income Taxes                             1,943         1,543              2,532         1,847
Provision for income taxes                               778           617              1,013           739
-------------------------------------------------------------------------------------------------------------

Net Income                                             1,165           926              1,519         1,108
Dividends on preferred shares                              7             7                 14            14
-------------------------------------------------------------------------------------------------------------

Net Income Available for Common Shares               $ 1,158       $   919            $ 1,505       $ 1,094
-------------------------------------------------------------------------------------------------------------

Earnings per Common Share:
     Basic                                           $  0.27       $  0.22            $  0.35       $  0.26
     Diluted                                         $  0.26       $  0.21            $  0.34       $  0.26
-------------------------------------------------------------------------------------------------------------

Cash Dividends per Common Share                      $  0.08       $ 0.072            $  0.16       $  0.144
-------------------------------------------------------------------------------------------------------------

Weighted Average Outstanding Common Shares:
     Basic                                             4,277         4,183              4,254          4,178
     Diluted                                           4,401         4,289              4,380          4,278
-------------------------------------------------------------------------------------------------------------
</TABLE>

   See accompanying notes to condensed consolidated financial statements.

                                       1
<PAGE>

                 Southwest Water Company and Subsidiaries
                   CONDENSED CONSOLIDATED BALANCE SHEETS
<TABLE>
<CAPTION>
                                                                         June 30,         December 31,
-------------------------------------------------------------------------------------------------------
ASSETS                                                                     1999              1998
-------------------------------------------------------------------------------------------------------
                                                                       (unaudited)
                                                                               (in thousands)
<S>                                                                       <C>              <C>
Current Assets:
Cash and cash equivalents                                                $    209         $    394
Customers' accounts receivable, net                                         9,008            8,630
Other current assets                                                        2,945            2,586
-------------------------------------------------------------------------------------------------------
                                                                           12,162           11,610
Property, Plant and Equipment:
Utility property, plant and equipment -- at cost                          148,873          144,690
Contract operations property, plant and equipment -- at cost                5,131            4,678
-------------------------------------------------------------------------------------------------------
                                                                          154,004          149,368
Less accumulated depreciation and amortization                             42,192           40,130
-------------------------------------------------------------------------------------------------------
                                                                          111,812          109,238

Other Assets                                                                8,878            9,079
-------------------------------------------------------------------------------------------------------
                                                                         $132,852         $129,927
-------------------------------------------------------------------------------------------------------

LIABILITIES AND STOCKHOLDERS' EQUITY
-------------------------------------------------------------------------------------------------------
Current Liabilities:
Current portion of bank notes payable and long-term debt                 $  1,602         $  1,679
Accounts payable                                                            1,398            2,782
Other current liabilities                                                  11,387            9,827
-------------------------------------------------------------------------------------------------------
                                                                           14,387           14,288
Other Liabilities and Deferred Credits:
Long-term debt                                                             28,900           28,900
Bank notes payable                                                          4,260            4,500
Advances for construction                                                   8,472            8,049
Contributions in aid of construction                                       32,415           31,706
Deferred income taxes                                                       4,767            4,430
Other liabilities and deferred credits                                      3,139            2,911
-------------------------------------------------------------------------------------------------------
Total Liabilities and Deferred Credits                                     96,340           94,784

Stockholders' Equity
Cumulative preferred stock                                                    517              517
Common stock                                                                   42               42
Paid-in capital                                                            30,673           30,127
Retained earnings                                                           5,280            4,457
-------------------------------------------------------------------------------------------------------
Total Stockholders' Equity                                                 36,512           35,143
-------------------------------------------------------------------------------------------------------
                                                                         $132,852         $129,927
-------------------------------------------------------------------------------------------------------
</TABLE>

See accompanying notes to condensed consolidated financial statements.

                                       2
<PAGE>
             Southwest Water Company and Subsidiaries
         CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
                           (Unaudited)

<TABLE>
<CAPTION>
                                                                                     Six Months Ended
                                                                                          June 30,
---------------------------------------------------------------------------------------------------------------
                                                                                  1999                1998
---------------------------------------------------------------------------------------------------------------
                                                                                       (in thousands)
<S>                                                                             <C>                  <C>
Cash Flows From Operating Activities:
Net Income                                                                      $ 1,519              $ 1,108
Adjustments to reconcile net income to
    net cash provided by operating activities                                     2,289              $ 1,672
---------------------------------------------------------------------------------------------------------------
Net cash provided by operating activities                                         3,808                2,780
---------------------------------------------------------------------------------------------------------------

Cash Flows From Investing Activities:
Additions to property, plant and equipment                                       (4,246)              (4,072)
Other investments, net                                                              125                  120
---------------------------------------------------------------------------------------------------------------
Net cash used in investing activities                                            (4,121)              (3,952)
---------------------------------------------------------------------------------------------------------------

Cash Flows From Financing Activities:
Net proceeds from dividend reinvestment plan,
     employee stock purchase plan, and stock option plans                           557                  216
Contributions in aid of construction and advances for construction                  704                1,272
Dividends paid                                                                     (696)                (614)
Net repayment of bank notes payable                                                (317)                (520)
Payments on advances for construction                                              (120)                (130)
---------------------------------------------------------------------------------------------------------------
Net cash provided by financing activities                                           128                  224
---------------------------------------------------------------------------------------------------------------

Net decrease in cash and cash equivalents                                          (185)                (948)
Cash and cash equivalents at beginning of period                                    394                1,237
---------------------------------------------------------------------------------------------------------------
Cash and cash equivalents at end of period                                      $   209              $   289
---------------------------------------------------------------------------------------------------------------

Supplemental Disclosure of Cash Flow Information:
Cash paid during the period for:
     Interest                                                                   $ 1,482              $ 1,556
     Income taxes                                                                  $285                 $380
Depreciation and amortization                                                   $ 2,244              $ 2,220
Non-cash contributions in aid of construction
     conveyed to Company by developers                                          $   934              $ 1,775
</TABLE>

See accompanying notes to condensed consolidated financial statements.

                                       3
<PAGE>

                    SOUTHWEST WATER COMPANY AND SUBSIDIARIES
              NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
                                 JUNE 30, 1999
                                  (Unaudited)


1.   Southwest Water Company ("the Company" or "Registrant") together with its
     subsidiaries is engaged in the water management business, providing water
     and wastewater services to nearly three-quarters of a million people
     located throughout California, Texas, New Mexico and Mississippi. Through
     its wholly owned subsidiary, ECO Resources, Inc. ("ECO"), the Company
     operates and manages water and wastewater treatment facilities owned by
     cities, municipal utility districts and private entities. The Company
     conducts regulated water utility operations through two wholly owned
     subsidiaries, Suburban Water Systems ("Suburban"), and New Mexico
     Utilities, Inc. ("NMUI"). The unaudited condensed consolidated financial
     statements reflect all adjustments, which, in the opinion of management,
     are necessary to present fairly the financial position of the Company as of
     June 30, 1999, and the Company's results of operations for the three and
     six months ended June 30, 1999. All such adjustments are of a normal
     recurring nature. Certain reclassifications have been made to the 1998
     financial statements to conform to the 1999 presentation.

2.   Certain information and footnote disclosures normally included in financial
     statements prepared in accordance with generally accepted accounting
     principles have been condensed or omitted pursuant to the rules and
     regulations of the Securities and Exchange Commission. These condensed
     consolidated financial statements should be read in conjunction with the
     financial statements and related notes contained in the Company's Annual
     Report on Form 10-K for the year ended December 31, 1998 ("the 1998 Annual
     Report").

3.   The water services industry is seasonal and as such, the results of
     operations for the six months ended June 30, 1999 do not necessarily
     indicate the results to be expected for the full year. Rainfall and weather
     conditions affect utility operations, with most water consumption occurring
     during the second and third quarters of each year when weather tends to be
     hot and dry. The first and fourth quarters of each year are normally the
     lowest in terms of average customer water usage for the Company's water
     utilities. The Company's contract operations business is also seasonal in
     nature and may be affected by adverse weather conditions. For example,
     heavy rainfall during a quarter would hamper the Company's ability to
     perform billable work such as pipeline maintenance, manhole rehabilitation
     and other outdoor services.

4.   The Company records earnings per share ("EPS") by computing basic EPS and
     diluted EPS. Basic EPS measures the performance of the Company over the
     reporting period by dividing net income available to common stockholders by
     the weighted-average number of common shares outstanding during the period.
     Diluted EPS measures the performance of the Company over the reporting
     period after giving effect to all potentially dilutive common shares that
     would have been outstanding if such shares had been issued. Common
     equivalent shares arise from stock options.

5.   Beginning in 2000, the Company is subject to SFAS No. 133, "Accounting for
     Derivative Instruments and Hedging Activities", which establishes
     accounting and reporting standards for derivatives. Currently, the Company
     does not have any derivative instruments which require disclosure under
     SFAS No. 133, and SFAS No. 133 is not expected to have any effect on the
     Company's financial position or results of operations.

6.   In August 1999, a 3-for-2 stock split in the form of a stock dividend was
     declared by the Company's board of directors, payable on October 20, 1999
     to stockholders of record as of October 1, 1999. The 1998 earnings per
     common share, cash dividends per common share and weighted-average
     outstanding common shares reflect a 5-for-4 stock split, paid in the form
     of a stock dividend to stockholders of record on October 1, 1998.

                                       4
<PAGE>

7.   As discussed in the 1998 Annual Report, in 1996 the Company purchased a 49%
     interest in Windermere Utility Company ("Windermere"), and in May 1999, the
     Company signed a third amendment to the RTNT Right of First Refusal
     Agreement and RTNT Call Purchase Agreement ("the Agreements"). The
     Agreements permit the majority shareholder to acquire the Company's
     interest in Windermere at an agreed-upon price. If the majority shareholder
     does not exercise his option, then the Company has the right to acquire
     100% of Windermere. The amendment extends to September 30, 1999, the date
     by which the majority shareholder can exercise this right.

8.   As discussed in the 1998 Annual Report, in August 1998, Suburban was
     granted an Exclusive Negotiation Agreement ("negotiation agreement") with
     an original term of 120 days by the City of West Covina ("West Covina").
     The negotiation agreement was subsequently extended to October 1999. The
     purpose of the agreement is for Suburban and West Covina to establish a
     price that will allow West Covina to divest itself of its water
     distribution system and facilities. Completion of negotiations would allow
     Suburban to purchase West Covina's water system, adding approximately 7,000
     water connections to Suburban's current customer base, an increase of
     approximately 11 percent. During August 1999, the West Covina City Council
     voted unanimously to put the proposal through a mail-in ballot process
     before the customers located within the West Covina city boundaries.
     Although there is support for this proposal among City Council members and
     others, there is also local citizen opposition to the sale. While West
     Covina and the Company are working toward a successful completion of this
     acquisition, there can be no assurance that the acquisition will occur.

9.   As discussed in the 1998 Annual Report, the City of Albuquerque
     ("Albuquerque") has initiated an action in eminent domain to acquire the
     operations of NMUI. At present, discussions are ongoing; however, there is
     no assurance that these discussions will lead to a settlement of the legal
     action, or that a resolution will be reached quickly.

10.  As discussed in the 1998 Annual Report, the Company has two reportable
     segments as defined under the requirements of SFAS No. 131, "Disclosures
     about Segments of an Enterprise and Related Information". The basis of
     segmentation and the basis of measurement of the segment profit or loss are
     the same as the information reported in the 1998 Annual Report. The
     following table sets forth disclosure about the Company's reportable
     segments as required by SFAS No. 131.

<TABLE>
<CAPTION>

                                                                    Total                          Total
                                       Non-                         Segment                     Consolidated
     For the Six Months Ended,       Regulated     Regulated      Information        Other      Information
 --------------------------------------------------------------------------------------------------------------
                                                                  (in thousands)
    <S>                                 <C>           <C>             <C>            <C>            <C>

June 30, 1999
-------------

Revenues from external customers    $ 18,831        $ 17,272       $ 36,103        $       0      $ 36,103

Segment operating profit                 501           5,168          5,669           (1,919)        3,750

Segment assets                        10,013         118,516        128,529            4,323       132,852

June 30, 1998
-------------

Revenues from external customers    $ 18,605        $ 15,673       $ 34,278        $       0      $ 34,278

Segment operating profit                 414           4,411          4,825           (1,619)        3,206

Segment assets                         9,888         112,835        122,723            3,728       126,451

</TABLE>


                                       5
<PAGE>

                 ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS
                OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

LIQUIDITY AND CAPITAL RESOURCES:

Liquidity and capital resources of the Company are influenced primarily by
construction expenditures at Suburban for the replacement and renovation of
water utility facilities and by construction expenditures for new water and
wastewater utility facilities at NMUI.  The Company's cash flow may also be
influenced by new business development and acquisition costs.

At June 30, 1999, the Company had cash and cash-equivalent balances totaling
$209,000.  The Company has three separate unsecured lines of credit from three
commercial banks, which expire in 2000.  The Company expects to renew expiring
lines of credit in the normal course of business. At June 30, 1999, outstanding
borrowing was $4,962,000 and the unused borrowing capacity was $11,038,000.
During the first six months of 1999, the Company repaid $317,000 on its lines of
credit.  As of June 30, 1999, the Company was in compliance with all applicable
financial covenants as required by its line of credit agreements. During July
1999, the Company negotiated and signed a new agreement with a commercial bank
and increased its total line of credit capacity by $2,000,000 to $18,000,000.
This agreement replaces one of the existing lines of credit.  Under the new line
of credit agreement, interest is charged at the bank's prime rate less  1/4-
percent.  The new agreement also allows the Company to borrow at an interest
rate that is lower than the bank's prime rate less  1/4-percent; however,
certain minimum borrowing requirements must be maintained for a fixed period of
time.  No commitment fee on the unused line of credit amount is required under
the new agreement.

In addition to its lines of credit, the Company has existing borrowing capacity
under its First Mortgage Bond Indentures.  Under these indentures, the Company
has remaining borrowing capacity of approximately $38,552,000.  However, the
amount of additional borrowing available to the Company under its current lines
of credit is limited by financial covenants that restricted additional borrowing
at June 30, 1999 to the unused credit line amount.

During the first six months of 1999, the Company's additions to property, plant
and equipment were $5,180,000, representing a decrease of $667,000 from the same
period in 1998.  Developers made contributions in aid of construction ("CIAC"),
and advances totaling $1,638,000 of which $704,000 was received in cash.
Company-financed capital additions were $3,542,000, which was paid for primarily
by cash flow from operations.  For 1999, the Company estimates that its capital
additions will be approximately $8,500,000 and that cash flow from operations
and CIAC will fund these additions.  Line of credit borrowing is also available
to meet construction requirements if operations or CIAC do not fund additions.

The Company anticipates that its available line of credit borrowing capacity and
the cash flow generated from operations will be sufficient to fund its
activities over the next 12 months.  If additional cash were needed, the Company
would consider alternative sources, including long-term financing.  The amount
and timing of any future long-term financing would depend on various factors,
including the timeliness and adequacy of rate increases, the availability of
capital, and the Company's ability to meet interest and fixed charge coverage
requirements.  Regulatory approval is required for any long-term financing by
Suburban or NMUI.  If the Company were unable to renew its existing lines of
credit or unable to obtain additional long-term financing, capital spending
would be reduced or delayed until new financing arrangements were secured.  Such
financing arrangements could include seeking equity financing through a private
placement or a public offering.  Similarly, if the Company were to need
additional cash to fund an acquisition, financing arrangements could include
long-term borrowing or equity financing.

REGULATORY AFFAIRS:

  Regulation:

                                       6
<PAGE>

ECO's pricing is not subject to regulation by a public utilities commission.
Most contracts with municipal utility districts ("MUDs") are short-term
contracts and do not generally include inflation adjustments.  Changes in prices
are negotiated on a contract-by-contract basis. ECO's operations and maintenance
contracts ("O&Ms") are generally longer-term water and wastewater service
contracts, primarily with cities, and typically include inflation adjustments.

The California Public Utilities Commission ("CPUC") and the New Mexico Public
Regulatory Commission ("NMPRC") (formerly the New Mexico Public Utility
Commission), regulate the rates and operations of Suburban and NMUI,
respectively.  The rates allowed are intended to provide the utilities an
opportunity to recover costs and earn a reasonable return on common equity.
Although the Company is not currently seeking any rate increase, future
construction expenditures and increased direct operating expenses may require
periodic requests for rate increases in the future.

  Regulatory Developments:

Legislative and CPUC developments are closely monitored by the Company and by
the various water industry associations in which the Company actively
participates.  In New Mexico, a legislative committee continues to review
proposed changes to the Public Utilities Act (the "PUA").  Whether legislative,
CPUC or PUA changes will be enacted, or, if enacted, what the terms of any
changes would be, are not known by the Company.  Therefore, management cannot
predict the impact, if any, of final legislative changes, CPUC-developments or
PUA changes on the Company's financial position or results of operations.


ENVIRONMENTAL AFFAIRS:

As a contract operator, ECO does not own any of the water sources, water
production facilities, or water distribution systems that it operates for its
clients, nor does ECO own any of the wastewater collection systems or wastewater
treatment facilities that it operates.  Although not the owner, ECO is
responsible for operating these water and wastewater facilities in compliance
with all federal, state and local health standards and regulations.

Suburban and NMUI operations fall under the regulatory jurisdiction of the CPUC
and the NMPRC, respectively.  The responsibilities of both regulatory agencies
are to ensure an adequate supply of healthful, potable water to residents of
their respective states.  The Company's operations are also subject to water and
wastewater pollution prevention standards and water and wastewater quality
regulations of the United States Environmental Protection Agency (the "EPA") and
various state regulatory agencies.  Both the EPA and state regulatory agencies
require periodic testing and sampling of water.  Costs associated with the
testing of the Company's water supplies have increased and are expected to
increase further as the regulatory agencies adopt additional monitoring
requirements.  The Company believes that future incremental costs of complying
with governmental regulations, including capital expenditures, will be
recoverable through increased rates and contract operations revenues.  However,
there is no assurance that recovery of such costs will be allowed. To date, the
Company has not experienced any material adverse effects upon its operations
resulting from compliance with governmental regulations.

YEAR 2000 ISSUE:

The Year 2000 ("Y2K") issue is the result of software applications using a two-
digit code instead of a four-digit code to identify the year.  Such applications
may be unable to interpret dates beyond 1999, which could result in system
failure or other erroneous data in the year 2000 causing serious disruptions in
operations. As discussed in the Company's 1998 Annual Report, the Company began
evaluating the Y2K issue in 1998 and has implemented a five-phase plan to assess
its exposure from potential Y2K-related failures in its internal systems and
those of its significant suppliers, vendors and customers.

The first phase of the plan was to conduct an inventory of all systems and
programs to determine which might be affected by the Y2K issue.  The second
phase involved assessment and determination as to

                                       7
<PAGE>

how to correct any Y2K issues that were identified in the first phase of the
Company's plan. The third phase of the plan involved implementation and testing
of the corrective measures. The fourth phase of the plan was to ensure that all
significant Y2K issues were properly corrected and all critical internal systems
were made Y2K compliant. The final phase of the plan is to assess whether the
Company's principal suppliers, vendors and material customers have Y2K issues
that could adversely affect the Company.

The first four phases of the plan were completed in 1998 and early 1999.  The
fifth phase of the plan involves the Company contacting principal suppliers and
vendors, all single source suppliers and vendors, and material customers
including local governments and municipal utility districts to assess their
readiness for Y2K.  Phase five is ongoing as the Company continues to make
inquiries with respect to Y2K compliance of these other systems; however; the
Company has not received assurances that all of those other systems are Y2K
compliant.  If systems of principal suppliers and vendors are found to be non-
compliant, the Company has appropriate written contingency plans.  However, the
Company is unable to predict whether there will be a material adverse effect on
the Company's financial position or results of operations since the final
determination of the Y2K compliance of principal suppliers, vendors and material
customers is not known at this time.  The Company does not expect implementation
of Y2K compliance measures to exceed $100,000.  The Company relies on relatively
low technological equipment and processes for its water and wastewater treatment
operations.  If necessary, the Company has the ability to operate its water and
wastewater systems manually should internal computer systems fail.  On January
1, 2000, the Company plans to have operations personnel on site and available to
operate the systems manually in the event that any internal computer systems
fail.  However, a long-term loss of electrical or gas power would have a
material adverse effect on the operations of the Company, the Company's
financial position and the results of operations.

RISK FACTORS

Certain statements contained in this Form 10-Q Report for the period ending June
30, 1999 are forward-looking statements within the meaning of the Private
Securities Litigation Reform Act of 1995.  Such forward-looking statements
involve known and unknown risks, uncertainties and other factors that may cause
actual results, performance or achievements of the Company to be materially
different from any performance or achievements planned, expressed or implied by
such forward-looking statements.  Although the Company believes that its
expectations are based on reasonable assumptions within the bounds of its
knowledge of its business and operations, there can be no assurance that actual
results will not differ materially from its expectations.

This Form 10-Q Report for the period ending June 30, 1999 should be read in
conjunction with the Company's 1998 Annual Report for more detailed descriptions
of the risk factors affecting the Company which include, but are not limited to,
expectations regarding new contracts and potential acquisitions, weather
conditions, water quality issues, regulatory changes, legal and other
contingencies.

                                       8
<PAGE>

RESULTS OF OPERATIONS:

All earnings per share amounts reflect a 5-for-4 stock split paid in the form of
a stock dividend to stockholders of record on October 1, 1998.

Three Months Ended June 30, 1999 Compared To Three Months Ended June 30, 1998

Diluted earnings per common share were $.26 in 1999 compared to $.21 during the
same period in 1998.

Operating income increased $387,000 or 18%, and, as a percentage of operating
revenues, was 13% in 1999 compared with 12% in 1998.  Contract operating income
increased $115,000, due primarily to the addition of new contracts and to an
increase in the amount of project work performed outside the scope of existing
contracts.  Operating income at the utilities increased $348,000, due primarily
to a 12% increase in water consumption by Suburban's customers as a result of
hot, dry weather during the quarter, as compared with more wet weather in 1998.
At NMUI, there was an increase in both water consumption and the number of
customers.  Parent company expenses increased $76,000 due primarily to
compensation-related expenses.

  Operating revenues

Operating revenues increased $1,122,000 or 6% in the second quarter of 1999
compared with the same period in 1998.  Contract revenues increased $406,000 or
4%, due to the addition of new contracts and increased project work performed
outside the scope of existing contracts.  Utility revenues increased $716,000 or
8% due primarily to increased water consumption by Suburban's customers as a
result of the hot, dry spring weather.  NMUI also experienced warmer than normal
weather and an increase in the number of its customers.

  Direct operating expenses

Direct operating expenses increased $770,000 or 6%.  As a percentage of
operating revenues, these expenses were 72% in both 1999 and 1998.  ECO's direct
operating expenses increased $235,000 relative to the increase in the number of
new contracts and to the increase in project work performed. Utility direct
operating expenses increased $535,000, primarily reflecting the increase in
customer water consumption and an increase in the number of NMUI's customers.

  Selling, general and administrative

Selling, general and administrative expenses for the second quarter of 1999
decreased $35,000 or 1% as compared with the same period in 1998.  As a
percentage of operating revenues, these expenses were 15% in 1999 and 16% in
1998.  Contract selling, general and administrative expenses increased $48,000,
primarily due to increased regional marketing costs associated with new business
development opportunities.  General and administrative expenses at the utilities
decreased $159,000, primarily as a result of decreased compensation-related
expenses and legal fees.  As discussed above, general and administrative
expenses of the parent company increased $76,000.

Six Months Ended June 30, 1999 Compared To Six Months Ended June 30, 1998

Diluted earnings per common share were $.34 in 1999 compared to $.26 during the
same period in 1998.

Operating income increased $544,000 or 17%, and, as a percentage of operating
revenues, was 10% in 1999 compared with 9% in 1998.  ECO's operating income
increased $87,000 due to the addition of new contracts and increases in project
work performed outside the scope of existing contracts.  Operating income at the
utilities increased $757,000, due primarily to a 15% increase in water
consumption by Suburban's customers as a result of hot, dry weather during the
first six months of 1999 compared to more wet weather in 1998.  At NMUI, there
was an increase in both water consumption due to warm, dry weather and an
increase in the number of customers resulting in a 16% increase in consumption
overall.

                                       9
<PAGE>

Parent company expenses increased $300,000 due primarily to self-insured
retention reserves related to litigation and to compensation-related expenses.

  Operating revenues

Operating revenues increased $1,825,000 or 5% for the first six months of 1999
compared with the same period in 1998.  Contract revenues increased $226,000 or
1%, primarily due to the addition of new contracts and to additional project
work performed outside the scope of existing contracts.  Utility revenues
increased $1,599,000 or 10% due primarily to increased water consumption by
Suburban's customers as a result of hot, dry spring weather.  NMUI also
experienced warmer than normal weather, which contributed to a 16% increase in
water consumption.

  Direct operating expenses

Direct operating expenses increased $1,147,000 or 5%.  As a percentage of
operating revenues, these expenses were 74% in both 1999 and 1998.  Contract
direct operating expenses increased $54,000 relative to the addition of new
contracts and to additional project work performed outside the scope of existing
contracts.  Utility direct operating expenses increased $1,093,000, primarily
reflecting the increase in customer water consumption at both Suburban and NMUI,
and to the increase in the number of NMUI's customers.

  Selling, general and administrative

Selling, general and administrative expenses for the first six months of 1999
increased $134,000 or 2% as compared with the same period in 1998.  As a
percentage of operating revenues, these expenses were 16% in both 1999 and 1998.
ECO's selling, general and administrative expenses increased $78,000, primarily
due to increased regional marketing costs associated with new business
development opportunities.  General and administrative expenses at the utilities
decreased $244,000, primarily as a result of decreased compensation-related
expenses and legal fees.  As discussed above, general and administrative
expenses of the parent company increased $300,000.

  Interest and other

Interest expense decreased $78,000 as the result of decreases in line of credit
borrowing and due also to lower interest rates in the first six months of 1999
compared to 1998.  Other income increased $65,000 due to a gain recorded by
Suburban for the sale of land not used in utility operations.

                                       10
<PAGE>

                          PART II - OTHER INFORMATION
                           ITEM 1.  LEGAL PROCEEDINGS

As discussed in the Company's 1998 Annual Report, Suburban and the Company were
served with a summons and an amended complaint in the Kristin Santamaria, et al
vs. Suburban Water Systems, et al action ("Santamaria").  The amended complaint
lists approximately 350 plaintiffs who contend, in essence, that they or
deceased family members are or were long-time residents of the San Gabriel
Valley ("the Valley") and that, by virtue of their residence in the Valley, they
have suffered long-term exposure to various hazardous substances in their
drinking water resulting in serious illness or, in some cases, wrongful death.
Of that number, 77 contend that they received their water from Suburban.
Suburban and the Company filed demurrers (i.e. motions to dismiss the action)
which alleged that the action must be dismissed because exclusive jurisdiction
of the subject matter rests with the CPUC.  On August 27, 1998, the Superior
Court Judge agreed and dismissed the case as to all water utility defendants.
The plaintiffs have appealed that decision.

As discussed in the Company's 1998 Annual Report, the Company and Suburban were
served with a summons and complaint in a second action entitled Christine
Boswell et al vs. Suburban Water Systems, et al, in the Los Angeles County
Superior Court. There are 14 plaintiffs and the allegations against Suburban are
similar to those in Santamaria.  The plaintiffs filed a petition in the Court of
Appeal requesting that the trial court be required to terminate a stay order
issued with respect to this action and rule on the demurrers filed by the
defendants.  The water utility defendants asked the Court of Appeal to order the
trial court to dismiss these actions based on the exclusive jurisdiction of the
CPUC.  This matter has now been consolidated with the Santamaria appeal and a
decision is expected in the next several months.

A third action, Anthony Anderson, et al vs. Suburban Water Systems, et al was
filed in the Los Angeles County Superior Court.  The allegations of the Anderson
action are virtually identical to the Santamaria action and involve
approximately 180 plaintiffs.  Of that number, 57 claim to be customers of
Suburban.  By stipulation of the parties, this case is stayed pending the
outcome of the Santamaria appeal.

A fourth action, Demciuc, et al vs. Suburban Water Systems, et al was filed in
the Los Angeles County Superior Court.  In that case, 10 consumers are making
claims against Suburban. That action is similar to the Boswell action and
involves two other water purveyors and five industrial defendants.  All of the
parties to the Demciuc action have agreed to stay that action pending the
outcome of the Boswell petitions.

The Company and Suburban have recently been added as defendants in the following
cases: Georgiana Dominguez vs. Southern California Water Company, et al, Jeff
Adler vs. Southern California Water Company, et al, Loretta Celi vs. San Gabriel
Valley Water Company, et al, and Shamille A. Criner vs. San Gabriel Water
Company, et al, all pending in the Los Angeles County Superior Court.  These
complaints are similar to the complaints in the Boswell and Demciuc cases
discussed above.  These complaints relate to non-Suburban customers.  These
cases are all stayed pending resolution of the Boswell petition and other
related appellate court proceedings.

The Company and Suburban intend to vigorously defend all actions, and have
requested defense and indemnification from their liability insurance carriers.
Several of the liability insurance carriers are currently contributing to the
costs of defense of the lawsuits.  Based upon information available at this
time, management does not expect that these actions will have a material adverse
effect on the Company's financial position or results of operations.

Suburban has applied for and received CPUC authority to establish and maintain a
memorandum or tracking account to accumulate all costs and fees incurred by
Suburban in defense of these actions and any similar actions which may be filed.
The Company and Suburban are unable to estimate or predict whether the CPUC will
ultimately allow Suburban to recover these accumulated costs and fees from
Suburban's customers or, if such recovery is allowed, how much of such costs and
fees will be recoverable.

                                       11
<PAGE>

In March 1998, the CPUC issued an order instituting investigation ("OII")
directed to all Class A and B water utilities in California, including Suburban.
The purpose of the OII is to address a series of questions dealing with the
safety of current drinking water standards and compliance with those standards.
Additional information about the OII is set forth in the 1998 Annual Report.
While the CPUC is actively investigating the issues concerned with water
quality, the Company and Suburban are unable to predict what actions, if any,
will be taken by the CPUC and/or the Department of Health Services as the result
of this investigation, or their impact on the operations or financial position
of the Company and Suburban.

As discussed in the 1998 Annual Report, in October 1998, the Company and ECO
were served with a summons and complaint in an action entitled Patrick K.
Accrocco, et al vs. ECO Resources, Inc., et al in the District Court of Fort
Bend County, Texas, arising out of a fatal auto accident.  The Company believes
that its maximum exposure in this action is limited to the self-insured
retention under its umbrella liability policy.  Based on the information
available at this time, management does not expect that this action will have a
material adverse effect on the Company's financial position or results of
operations.

As discussed in the 1998 Annual Report, the City of Albuquerque ("Albuquerque")
initiated an action in eminent domain to acquire the operations of NMUI. The
Company believes that the fair market value of NMUI is substantially in excess
of the amount offered in Albuquerque's complaint.  Under New Mexico state law,
there are procedures which would allow Albuquerque to take possession of NMUI
prior to the resolution of the fair market issue; however, the Company believes
that it has adequate defenses should Albuquerque choose to pursue these
procedures.  At present, discussions are ongoing; however, there is no assurance
that these discussions will lead to a settlement of the legal action.

The Company and its subsidiaries are the subjects of certain litigation arising
from the ordinary course of operations.  The Company believes the ultimate
resolution of such matters will not materially adversely affect its consolidated
financial position, results of operations or cash flow.

ITEM 4. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDER

At the Annual Meeting of Stockholders held on May 27, 1998, Maureen A. Kindel, a
member of the Board of Directors was reelected by the following votes: votes for
3,492,301; and votes abstaining  45,245. No broker non-votes were recorded.

The selection of KPMG LLP as the Company's independent auditors was ratified by
the following vote: votes for  3,485,230; votes against  10,332; and votes
abstaining  41,984.  No broker non-votes were recorded.

                                       12
<PAGE>

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

(a) Exhibits furnished pursuant to Item 601 of Regulation S-K:

  10.10E Third Amendment of SWWC Right of First Refusal and SWWC Call Purchase
         Agreement between the Registrant and RTNT, Inc. dated May 27, 1999,
         filed herewith.

  10.10F Third Amendment of RTNT Right of First Refusal and RTNT Call Purchase
         Agreement between the Registrant and RTNT, Inc. dated May 27, 1999,
         filed herewith.

  10.16  Modification Agreement between New Mexico Utilities, Inc. and First
         Security Bank of New Mexico, N.A. dated April 10, 1999, filed herewith.

  27     Financial Data Schedule.

(b)  Reports on Form 8-K

         None.

                                       13
<PAGE>

                                   SIGNATURES



Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned thereto duly authorized.



                                  SOUTHWEST WATER COMPANY
                                  -----------------------
                                  (Registrant)



Dated: August 12, 1999        /s/ Peter J. Moerbeek
                              ---------------------------
                                 Peter J. Moerbeek
                                 Chief Financial Officer

                                       14