Christopher T. Forsythe
Senior Vice President and Chief Financial Officer at Atmos Energy
Thank you, Kevin, and good morning, everyone.
Our fiscal '23 earnings per share of $6.10 increased 8.9% over fiscal '22. Our performance continues to reflect the successful execution of our operating, regulatory and financing strategies. In fiscal '23, we implemented $269 million of annualized operating income increases excluding the amortization of excess deferred tax liability. These outcomes combined with outcomes received in fiscal '22 increased operating income by $254 million this fiscal year. Strong customer growth, higher consumption and rising industrial load in our distribution segment increased operating income by an additional $30 million.
Consolidated O&M increased $55 million to $765 million, largely driven by higher levels of service orders and increased headcount to support our growing service territory, primarily in Texas. This thing came in at the lower end of our updated guidance range as we saw some moderation in inflation in the third and fourth fiscal quarters.
Fiscal '23 capital spending of $2.8 billion, represented 15% increase over the prior fiscal year. 85% of that spend was dedicated to improving the safety and reliability of our system. As a result of this spending, our rate base increased by 18%, and estimated $16.6 billion as of September 30. Finally, we completed $1.6 billion of long-term financing and completed the securitization process in Kansas and Texas. We finished the fiscal year with an equity capitalization of 61.5% and approximately $2.7 billion of available liquidity, which leaves us well-positioned to support our future operations.
Looking forward, our strategy continues to focus on system modernization and disciplined capital spending, seeking timely recovery of our costs through our regulatory mechanisms, while financing our operations using a balance of equity and long-term debt to preserve the strength of our balance sheet, mitigate financing risk and minimizing the cost of financing to our customers. We anticipate the execution of this strategy will continue to support 6% to 8% annual earnings per share and dividend per share growth.
For fiscal '24, we anticipate earnings per share will be between $6.45 and $6.65, and we anticipate fiscal '28 earnings per share to be in the range of $8.35 and $8.75. Additionally, Atmos Energy's Board of Directors approved a 160th consecutive quarterly cash dividend as an indicated fiscal '24 annual dividend of $3.22, an 8.8% increase over fiscal '23. This plan anticipates total capital spending of approximately $17 billion. This level of spending will continue to support rate base growth of about 11% to 13% per year, which is expected to increase estimated rate base by approximately or to approximately $29 billion in fiscal '28.
In addition to our capital spending, another significant use of cash will be for taxes. We expect to refund $300 million of excess deferred tax liabilities over the next five years, with approximately 70% of this amount be funded during fiscal '24 and fiscal '25. And we anticipate we will become a material federal cash tax payer within the next three years because of 15% corporate minimum tax that was included in the Inflation Reduction Act.
Our O&M spending will continue to focus on compliance-based activities that address this in safety. We have assumed O&M inflation of 3.5% annually through fiscal '28 from fiscal '23 levels. For fiscal '24, we anticipate O&M to range from $780 million to $800 million. This five-year plan includes approximately $10 million [Phonetic] of incremental long-term debt and financing, which has been reflected in our earnings per share guidance for both fiscal '24 and fiscal '28.
Following the completion of our $900 million long-term debt issuance in October, our weighted average cost of debt stood at 4.1%, and our debt maturity schedule is very manageable. Our weighted average maturity is 18.4 years, and our next significant tranche of debt is not scheduled to mature until June of 2027.
Additionally, our financing strategy does not contemplate material exposure to floating rate -- interest rates. To further mitigate interest rate risk, we have $900 million in forward starting interest rate swaps in place to hedge portions of our anticipated long-term debt issuances in fiscal 2025 and '26. The effective weighted average rate of these swaps is 1.59%.
Finally, we intend to continue utilizing our ATM program to meet our equity financing needs. As of September 30, we have priced $467 million, which represents a significant portion of our anticipated fiscal '24 equity need. Finally, recovery of our costs remains a key component of our strategy. We are off to a good start in fiscal '24.
Since the beginning of this fiscal year, we had implemented $113 million in annualized operating income increases in our Distribution segment, and we have five filings in progress taking about $137 million. Included in this amount is $107 million requested in APT's general rate case. On October 24, APT and the intervening parties filed a comprehensive settlement agreement with the Texas Railroad Commission. The settlement proposes a rate base of $4.3 billion, an authorized rate of return of 8.49%, equity capitalization of 60.44% and an authorized ROE of 11.45%.
We anticipate the settlement agreement will be on the commission's agenda for its December 13th meeting. If approved as filed, this settlement would result in a $27 million increase in annualized operating income. We remain confident the execution of this strategy will continue to support our ability to modernize our system and to support the continued economic development in our service territories. Our customers will continue to benefit from this strategy as we expect our average residential bill will remain one of the most competitively priced utility bills in our customers' health.
Thank you for your time this morning. I will now turn the call back over to Kevin for some closing remarks. Kevin?
