<TABLE> <S> <C>
<PAGE>
<ARTICLE> UT
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM FORM 10-Q
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-END> JUN-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 1,715,242
<OTHER-PROPERTY-AND-INVEST> 31,389
<TOTAL-CURRENT-ASSETS> 550,230
<TOTAL-DEFERRED-CHARGES> 929,147
<OTHER-ASSETS> 0
<TOTAL-ASSETS> 3,226,008
<COMMON> 0
<CAPITAL-SURPLUS-PAID-IN> 475,700
<RETAINED-EARNINGS> 254,371
<TOTAL-COMMON-STOCKHOLDERS-EQ> 730,071
49,399
43,000
<LONG-TERM-DEBT-NET> 1,194,279
<SHORT-TERM-NOTES> 61,500
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 0
<LONG-TERM-DEBT-CURRENT-PORT> 133,428
0
<CAPITAL-LEASE-OBLIGATIONS> 0
<LEASES-CURRENT> 0
<OTHER-ITEMS-CAPITAL-AND-LIAB> 1,014,331
<TOT-CAPITALIZATION-AND-LIAB> 3,226,008
<GROSS-OPERATING-REVENUE> 775,735
<INCOME-TAX-EXPENSE> 29,681
<OTHER-OPERATING-EXPENSES> 652,197
<TOTAL-OPERATING-EXPENSES> 681,878
<OPERATING-INCOME-LOSS> 93,857
<OTHER-INCOME-NET> 3,501
<INCOME-BEFORE-INTEREST-EXPEN> 97,358
<TOTAL-INTEREST-EXPENSE> 50,550
<NET-INCOME> 46,808
2,980
<EARNINGS-AVAILABLE-FOR-COMM> 0
<COMMON-STOCK-DIVIDENDS> 15,000
<TOTAL-INTEREST-ON-BONDS> 51,079
<CASH-FLOW-OPERATIONS> 65,299
<EPS-BASIC> 0
<EPS-DILUTED> 0
</TABLE>
