SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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FORM 8-K/A

AMENDMENT NO. 1 TO
CURRENT REPORT

Pursuant to Section 13 or 15(d) of
the Securities Exchange Act of 1934

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Date of Report
(Date of earliest
event reported): February 20, 2001

Commission Name of Registrant, State of Incorporation, IRS Employer
File Number Address of Principal Executive Offices and Telephone Number Identification Number
- ------ ----------------------------------------------------------- ---------------------

1-9894 ALLIANT ENERGY CORPORATION 39-1380265
(a Wisconsin corporation)
222 West Washington Avenue
Madison, Wisconsin 53703
Telephone (608) 252-3311

0-4117-1 IES UTILITIES INC. 42-0331370
(an Iowa corporation)
Alliant Energy Tower
Cedar Rapids, Iowa 52401
Telephone (319) 398-4411

This joint Form 8-K/A is separately filed by Alliant Energy Corporation and IES
Utilities Inc.

The undersigned registrants hereby amend Item 5 of their Current Report on
Form 8-K dated February 20, 2001 to provide in its entirety as follows:

Item 5. Other Events and Regulation FD Disclosure.

Alliant Energy Corporation ("AEC") and IES Utilities Inc., an operating
public utility and a subsidiary of AEC ("IESU"), reported the following
information with respect to IESU and Interstate Power Company, a Delaware
corporation, an operating public utility and a subsidiary of AEC ("IPC").

SUMMARY OPERATING STATISTICS

As of December 31, 2000, IESU furnished retail electric service to
approximately 347,000 customers in 525 cities, villages and towns. IESU also
supplied wholesale electric service to five customers. During the nine-month
period ended September 30, 2000, IESU derived its electric operating revenues
from the following types of customers:

-- residential -- 37%

-- commercial -- 28%

-- industrial -- 29%

-- sales for resale -- 4%

-- other -- 2%.

The maximum net hourly peak load on IESU's electric system in the year
ended December 31, 2000 was 2,067 megawatts. At the time of the peak load on
IESU's system, IESU had the capacity to provide up to 2,143 megawatts of
electricity, including 1,916 megawatts of generated capacity and 227 megawatts
of purchased capacity under contract. During 2000, IESU's net kilowatt-hour
sources of electricity consisted of the following:

-- coal -- 52%

-- nuclear -- 26%

-- purchases -- 18%

-- natural gas - 3%

-- other -- 1%.

As of December 31, 2000, IESU provided retail natural gas service to
approximately 182,000 customers in 212 cities, villages and towns. During the
nine-month period ended September 30, 2000, IESU derived its gas operating
revenues from the following types of customers:

-- residential -- 60%

-- commercial -- 29%

-- industrial -- 8%

-- transportation and other -- 3%.

RECENT DEVELOPMENTS

The following information for the year ended December 31, 2000 has been
derived from IESU's and IPC's preliminary unaudited results of operations.

IES Utilities. IESU's earnings available for common stock increased 12.2%
to $73.5 million on operating revenues of $876.0 million for the year ended
December 31, 2000 compared to earnings available for common stock of $65.5
million on operating revenues of $800.7 million for the year ended December 31,
1999. IESU's operating income increased 3.9% to $167.8 million, or 19.2% of
operating revenues, for the year ended December 31, 2000 compared to $161.5
million, or 20.2% of operating revenues, for the year ended December 31, 1999.

The increase in IESU's earnings available for common stock and its
operating income was primarily due to reduced other operation and maintenance
expenses, higher electric and gas margins and lower tax expense primarily due to
a lower effective income tax rate. Those changes were partially offset by higher
depreciation and amortization expense due to property additions. Higher interest
income, largely due to a tax settlement realized in 2000, also contributed to
the increase in earnings available for common stock.

Reduced other operation and maintenance expenses were primarily due to
lower energy efficiency expenses and reduced administrative and general expenses
resulting from expenses incurred in 1999 relating to IESU's Year 2000 readiness
program and lower employee benefit costs. Such decreases were partially offset
by higher nuclear operation costs and one-time fees related to the transfer from
the Mid-Continent Area Power Pool reliability region to the Mid-America
Interconnected Network, Inc. region. Electric margin increased due to increased
sales resulting from economic growth, partially offset by the impact of a 1999
change in estimate of the utility services rendered but unbilled at month-end,
milder weather and reduced recoveries for Iowa-mandated energy efficiency
programs. Gas margin increased primarily due to increased sales resulting from
colder weather in the fourth quarter of 2000.

Interstate Power Company. IPC's earnings available for common stock
decreased 7.7% to $26.2 million on operating revenues of $358.0 million for the
year ended December 31, 2000 compared to earnings available for common stock of
$28.4 million on operating revenues of $342.1 million for the year ended
December 31, 1999. IPC's operating income decreased 7.5% to $56.8 million, or
15.9% of operating revenues, for the year ended December 31, 2000 compared to
$61.4 million, or 17.9% of operating revenues, for the year ended December 31,
1999.

The decrease in IPC's earnings available for common stock and operating
income was primarily due to increased other operation and maintenance expenses,
higher depreciation and amortization expense due to property additions and lower
gas margin. Those changes were partially offset by higher electric margin. The
changes' effect on earnings available for common stock was also partially offset
by reduced income tax expense due to a lower effective income tax rate.

The increase in other operation and maintenance expenses was primarily due
to increased energy efficiency expenditures and higher transmission and
distribution expenses. Such increases were partially offset by expenses incurred
in 1999 relating to IPC's Year 2000 readiness program and reduced employee
benefit costs. The lower gas margin resulted from reduced sales. The increased
electric margin was primarily due to higher sales resulting from economic
growth, increased capacity sales and higher recoveries for energy efficiency
programs. These items were partially offset by a 1999 change in estimate of
utility services rendered but unbilled at month-end and milder weather.

Pro Forma. The pro forma combined earnings available for common stock of
IESU and IPC, giving effect to the proposed merger, increased 6.2% to $99.7
million on pro forma combined operating revenues of $1,234.0 million for the
year ended December 31, 2000 compared to pro forma combined earnings available
for common stock of $93.9 million on pro forma combined operating revenues of
$1,142.8 million for the year ended December 31, 1999. Pro forma combined
operating income increased 0.8% to $224.6 million, or 18.2%

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of pro forma combined operating revenues, for the year ended December 31, 2000
compared to $222.9 million, or 19.5% of pro forma combined operating revenues,
for the year ended December 31, 1999.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934,
Alliant Energy Corporation and IES Utilities Inc. have each duly caused this
amendment to the report to be signed on its behalf by the undersigned hereunto
duly authorized on March 1, 2001.

ALLIANT ENERGY CORPORATION
Registrant

By: /s/ John E. Kratchmer Corporate Controller and Chief Accounting Officer
- --------------------------- (Principal Accounting Officer)
John E. Kratchmer

IES UTILITIES INC.
Registrant

By: /s/ John E. Kratchmer Corporate Controller and Chief Accounting Officer
- --------------------------- (Principal Accounting Officer)
John E. Kratchmer