<TABLE> <S> <C>
<PAGE>
<ARTICLE> UT
<LEGEND>
THIS SECTION OF THE SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED
FROM THE CONSOLIDATED FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<S> <C>
<MULTIPLIER> 1,000
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 1,029,270
<OTHER-PROPERTY-AND-INVEST> 0
<TOTAL-CURRENT-ASSETS> 28,353
<TOTAL-DEFERRED-CHARGES> 45,883
<OTHER-ASSETS> 0
<TOTAL-ASSETS> 1,103,506
<COMMON> 85,474
<CAPITAL-SURPLUS-PAID-IN> 192,717
<RETAINED-EARNINGS> 77,452
<TOTAL-COMMON-STOCKHOLDERS-EQ> 355,643
0
0
<LONG-TERM-DEBT-NET> 436,725
<SHORT-TERM-NOTES> 0
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 39,677
<LONG-TERM-DEBT-CURRENT-PORT> 31,000
0
<CAPITAL-LEASE-OBLIGATIONS> 15,130
<LEASES-CURRENT> 522
<OTHER-ITEMS-CAPITAL-AND-LIAB> 224,809
<TOT-CAPITALIZATION-AND-LIAB> 1,103,506
<GROSS-OPERATING-REVENUE> 113,025
<INCOME-TAX-EXPENSE> 17,205
<OTHER-OPERATING-EXPENSES> 48,467
<TOTAL-OPERATING-EXPENSES> 65,672
<OPERATING-INCOME-LOSS> 47,353
<OTHER-INCOME-NET> 197
<INCOME-BEFORE-INTEREST-EXPEN> 47,550
<TOTAL-INTEREST-EXPENSE> 20,379
<NET-INCOME> 27,171
0
<EARNINGS-AVAILABLE-FOR-COMM> 27,171
<COMMON-STOCK-DIVIDENDS> 0
<TOTAL-INTEREST-ON-BONDS> 14,645
<CASH-FLOW-OPERATIONS> 64,416
<EPS-BASIC> 27,171
<EPS-DILUTED> 27,171
</TABLE>
