<TABLE> <S> <C>
<PAGE>
<ARTICLE> UT
<S> <C>
<PERIOD-TYPE> 9-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> SEP-30-2000
<BOOK-VALUE> PER-BOOK
<TOTAL-NET-UTILITY-PLANT> 597,466
<OTHER-PROPERTY-AND-INVEST> 2,547
<TOTAL-CURRENT-ASSETS> 179,673
<TOTAL-DEFERRED-CHARGES> 37,171
<OTHER-ASSETS> 68,579
<TOTAL-ASSETS> 885,436
<COMMON> 51,418
<CAPITAL-SURPLUS-PAID-IN> 43,233
<RETAINED-EARNINGS> 177,361
<TOTAL-COMMON-STOCKHOLDERS-EQ> 272,012
16,737
0
<LONG-TERM-DEBT-NET> 210,000
<SHORT-TERM-NOTES> 0
<LONG-TERM-NOTES-PAYABLE> 0
<COMMERCIAL-PAPER-OBLIGATIONS> 104,734
<LONG-TERM-DEBT-CURRENT-PORT> 0
0
<CAPITAL-LEASE-OBLIGATIONS> 14,017
<LEASES-CURRENT> 545
<OTHER-ITEMS-CAPITAL-AND-LIAB> 267,391
<TOT-CAPITALIZATION-AND-LIAB> 885,436
<GROSS-OPERATING-REVENUE> 413,456
<INCOME-TAX-EXPENSE> 6,682
<OTHER-OPERATING-EXPENSES> 382,536
<TOTAL-OPERATING-EXPENSES> 389,218
<OPERATING-INCOME-LOSS> 24,238
<OTHER-INCOME-NET> 671
<INCOME-BEFORE-INTEREST-EXPEN> 24,909
<TOTAL-INTEREST-EXPENSE> 13,487
<NET-INCOME> 11,422
1,082
<EARNINGS-AVAILABLE-FOR-COMM> 10,340
<COMMON-STOCK-DIVIDENDS> 22,496
<TOTAL-INTEREST-ON-BONDS> 12,581
<CASH-FLOW-OPERATIONS> 82,173
<EPS-BASIC> 20.11
<EPS-DILUTED> 20.11
</TABLE>