John D. Porter
Senior Vice President and Chief Financial Officer at Williams Companies
Thanks, Alan. Starting here on Slide three with a summary of our year-over-year financial performance. Beginning with adjusted, we saw another strong quarterly increase of 8% over the prior year, and this happens to coincide with an 8.6% CAGR over the last five years for the same measure. And this strong performance included a new record for gathering volumes, which increased 6%. Year-to-date, our adjusted EBITDA is now up 13% driven by the growth of our core infrastructure businesses, which continued to perform very well even as natural gas price decreased 61% for the first half of 2023 versus the first half of 2022, once again demonstrating the resiliency and strength of our natural gas focused strategy, our assets and our operational capabilities.
For second quarter, our adjusted EPS increased 5% for the quarter, continuing the strong growth we've had in EPS over the last many years with our year-to-date EPS now up 23%. Available funds from operations, AFFO growth for second quarter was in line with adjusted EBITDA. And you see our second quarter dividend coverage based on AFFO was a very strong 2.23 times, growing about 2% despite growing our dividend by 5.3%. Our balance sheet continues to strengthen with debt to adjusted EBITDA now reaching three and a half times and versus last year's 3.82 times, and that's even after closing the Trace, NorTex and MountainWest acquisition and also repurchasing $139 million worth of shares since last year.
By capex, you see an increase primarily reflecting the progress we're making on some of our key growth projects, including Regional Energy Access and Louisiana Energy Gateway. For the full year, there is no change to our consolidated adjusted EBITDA guidance of $6.4 billion to $6.8 billion or any of our other guidance metrics. But in a moment, I'll provide a little color on our expectations for the remainder of the year versus the performance we've seen thus far in 2023. So let's turn to the next slide and take a little closer look at the second quarter results. A strong 8% increase in EBITDA over prior year even as average natural gas prices for the second quarter decreased 71%, walking now from last year's roughly $1.5 billion to this year's $1.6 billion, we start with our upstream joint venture operations that are included in our Other segment, which were down $43 million versus last year.
Our Haynesville upstream EBITDA was down about $14 million despite substantially higher production due to much lower net realized prices and a lower working interest percentage on new wells beginning in January of 2023. Our Wamsutter upstream EBITDA was down $29 million due primarily to lower realized prices, but production also continued to be impacted throughout April from the historically difficult Wyoming winter weather we saw in the first quarter. Shifting now to our core business performance. Our Transmission & Gulf of Mexico business improved $96 million or 15%, including about a $52 million contribution from our MountainWest Pipeline and NorTex acquisition, but with other increases in our transmission and deep water revenues as well.
Our Northeast G&P business performed extremely well with the $65 million or 14% increase driven by an $81 million increase in service revenues. And we did have a onetime $14 million favorable gathering revenue catch-up adjustment in that second quarter increase in service revenue. But this revenue increase was really fueled by a 6% increase in total volumes in the Northeast. Shifting now to the West, which increased to $16 million or 5%, benefiting from continued strong volume growth in the Haynesville and positive hedge results that partially offset the impact of lower commodity base rate. And then you see the $22 million decrease in our gas and NGL marketing business, and the majority of this decline was actually related to lower NGL marketing results from inventory valuation changes where we had a gain on NGL inventories last year but a loss this year.
So again, the second quarter continued our strong start to 2023 with 8% growth in EBITDA, driven by core infrastructure business performance in spite of natural gas prices that were 71% lower than second quarter of 2022. So let's turn the page and touch on the year-to-date comparison. Year-to-date, we've seen a 13% increase over 2022, walking now from last year's $3 billion to this year's $3.4 billion, we start with the upstream joint venture operations included in our Other segment, which were down $39 million versus last year. Now year-to-date, Haynesville is up nicely on very strong volume growth that has been significantly offset by lower realized prices.
However, the overall Haynesville increase was offset by lower one set of results due primarily to the historically difficult winter weather we saw in Wyoming this year. Shifting now to our core business performance. Transmission & Gulf of Mexico business improved $127 million or 9% and really similar themes as our second quarter, namely the impact of the MountainWest Pipeline and NorTex acquisition. However, we have seen other significant increases in our transmission and deepwater revenues as well. Our Northeast G&P business has performed very well with $117 million or 13% increase, driven by $154 million increase in service revenue. This revenue increase was fueled by a 7% increase in total volumes focused in our liquids-rich areas where we tend to have higher per unit margins than our dry gas areas.
And in the appendix, you'll find a slide that compares our 7% volume growth to the overall basin growth of just under 2%. Shifting now to the West, which increased $42 million or 8%, benefiting from positive hedge results and the Trace acquisition, but the West was significantly unfavorably impacted by the severe Wyoming weather and January processing economics at our Opal Wyoming processing plant. And then you see the $144 million increase in our gas and NGL marketing business caused by the strong first quarter that we had at the start of the year. So again, a continuation to the strong start to 2023 with 13% growth in EBITDA and driven by core infrastructure business performance with strength from our marketing business that dramatically overcame weaker-than-expected results from the upstream joint ventures.
So as I mentioned earlier, there's no change to our consolidated adjusted EBITDA guidance of $6.4 billion to $6.8 billion or any of our other guidance metrics. We've definitely had a strong start to the year with $3.4 billion of EBITDA through the first half of the year. And thanks to the performance of our base business, we have clear visibility to hitting at least the midpoint of our guidance even after a historic decline in natural gas prices and a historically difficult winter that continue to have impacts through April. So you may be wondering why we aren't raising our guidance on the back of such a strong start to the year and a bright future ahead.
First, I will remind you that our guidance does include a range of $200 million above our midpoint. And second, while we usually experience stronger third and fourth quarters than second quarter, the third quarter does occasionally see hurricane outages for our deepwater business. Finally, we could also still see downward shifts in natural gas prices for the balance of the year that could unfavorably impact our upstream joint ventures in particular. While we are not suggesting there is a high likelihood of realizing these impacts, we do need to be prepared to overcome these scenarios. Therefore, it is too early to raise our full year guidance.
But once again, we are confident in the continued performance of our base infrastructure businesses allowing us to once again meet or exceed the midpoint of our guidance range. We're setting our sights on continued growth in 2024 before another big growth step in 2025.
And with that, I'll turn it back to Alan.
