Capital Program Planning for Connecticut Gas Utilities

by | Oct 21, 2026

Connecticut · Natural Gas Utilities

Connecticut is planning for less gas — while your mains still have to last 50 years.

The three companies that deliver gas to roughly 660,000 Connecticut homes and businesses must keep replacing decades-old main in a state now targeting a 45% emissions cut by 2030 and steering new buildings toward heat pumps. Every replacement mile, integrity upgrade, and reliability asset competes for capital against a throughput curve that may bend down. Invizion helps gas utilities re-sequence a capital portfolio in a click — and defend every decision to PURA.

See how Invizion helps utilities See what Connecticut utilities face Download the briefing (PDF)
The bottom line: Connecticut is planning for less gas even as its utilities must keep replacing thousands of miles of aging main — and with no dedicated infrastructure surcharge and PURA cutting rates, the LDCs that succeed will be the ones whose capital plans can re-sequence as fast as the throughput and regulatory picture changes.
663,5861
Natural gas consumers in Connecticut in 2024 — about 597,512 of them residential.
8,100+ mi2
Distribution main operated by Connecticut Natural Gas and Southern Connecticut Gas alone.
55%3
Share of New England's electricity generated from natural gas in 2025 — a winter reliability pinch point.
45% by 20304
Connecticut's statutory greenhouse-gas cut below 2001 levels — pressure on long-run gas throughput.

The Connecticut Landscape

Four forces are moving your project list at once

None of these is theoretical, and none waits for the next budget cycle. Together they mean the capital plan approved last year may already be the wrong plan.

System Integrity & Aging Pipe

Thousands of miles of main, much of it old

Connecticut Natural Gas operates 3,871 miles of distribution main for 187,790 customers, and Southern Connecticut Gas another 4,242 miles for 208,601 — more than 8,100 miles between the two Avangrid companies alone.2 Eversource's Yankee Gas adds roughly 256,000 customers across 85 Connecticut towns.5

Much of that system was laid decades ago, including cast-iron and bare-steel main in the oldest districts of Hartford, New Haven and Bridgeport that must be replaced under PURA-approved integrity programs and PHMSA distribution-integrity rules. Replacement is non-discretionary safety spend — and it competes for the same capital as everything else.

Decarbonization & Electrification

The state is planning for less gas, not more

Connecticut law requires greenhouse-gas cuts of 45% below 2001 levels by 2030 and 65% by 2040, a zero-carbon electricity supply by 2040, and net zero by 2050.4 Policy is steering buildings toward heat pumps, putting the roughly 48 Bcf of gas delivered to Connecticut homes in 2024 on a long-run downward path.6

The reversal is already visible: the 2013 program that subsidized new gas hookups fell far short of its targets, and the state cut those subsidies short in 2022.7 Fewer new customers and flat-to-declining throughput mean the same infrastructure cost is spread over a shrinking base — the stranded-asset math that reshapes every long-horizon plan.

Supply, Price & Reliability

A gas-dependent region with a winter problem

Natural gas fuels about 55% of New England's electricity, and on the coldest days pipeline gas is committed to heating customers first, forcing the grid onto oil and imported LNG.3 Connecticut households feel the same squeeze: residential gas prices rose to $18.88 per thousand cubic feet in 2023 before easing to $16.83 in 2024.8

In January 2026 another deep freeze pushed New England back onto oil, reopening the fight over how the region secures winter fuel.9 Design-day planning, LNG peaking and storage are not optional line items here — they are the difference between reliable service and a cold-snap failure.

Capital Recovery & Regulation

Rate relief is no longer a formality

In 2024 Connecticut Natural Gas and Southern Connecticut Gas sought their first rate increase in five years; PURA instead proposed cutting their rates.10 Avangrid's gas utilities appealed the reduction in Superior Court.11

Eversource's Yankee Gas reset distribution rates in a PURA-approved case effective November 2025.5 Connecticut has no Massachusetts-style infrastructure surcharge (GSEP) or automatic DSIC for gas, so most capital is recovered through contested base-rate cases — where affordability pressure now collides directly with replacement and integrity spending.

Who Delivers Connecticut's Gas

Three investor-owned LDCs, one municipal system

Connecticut's gas distribution is almost entirely investor-owned and PURA-regulated, split between two Avangrid companies and Eversource's Yankee Gas. Beyond them, only the City of Norwich runs its own gas system.

Investor-owned gas LDCs

Rates & capital recovery regulated by PURA

Connecticut Natural Gas (CNG) 187,790 customers · 3,871 miles of main · Avangrid (2023)2
Southern Connecticut Gas (SCG) 208,601 customers · 4,242 miles of main · Avangrid (2023)2
Eversource Gas of Connecticut (Yankee Gas) ~256,000 customers · 85 towns5

Together the three LDCs serve about 660,000 Connecticut gas customers.1

Municipal & other gas

Governed locally, not by PURA rates

Norwich Public Utilities (NPU) Municipal · natural gas, electric, water & wastewater · Norwich, est. 190412
No gas cooperatives Connecticut has no member-owned natural-gas co-ops.
Much of the state: oil & propane Gas mains reach a minority of Connecticut towns; heating oil and propane still heat much of the state.

Norwich aside, Connecticut has effectively no public-power gas sector — unusual among the states, and it concentrates capital-planning scrutiny on the three PURA-regulated LDCs.

Rate-Setting & Oversight

Every capital dollar has to clear PURA

For the investor-owned LDCs, the question is the same on every filing: why this project, why now, why at this cost?

  • Public Utilities Regulatory Authority (PURA) sets rates and services for Connecticut's electricity, natural gas, water and telecom companies, including CNG, SCG and Yankee Gas.13
  • CNG & SCG 2024 rate case: the utilities sought their first increase in five years; PURA proposed rate cuts instead, and Avangrid appealed to Superior Court — a sharp signal that rate relief is contested.1011
  • Yankee Gas: Eversource reset its Connecticut gas distribution rates in a PURA-approved case effective November 2025.5
  • No standalone infrastructure surcharge: unlike Massachusetts' GSEP, Connecticut recovers gas main replacement and system spending mainly through base-rate cases — putting integrity capital in direct competition with bill affordability.10

How Capital Gets Recovered

Base rates, LNG assets, and a subsidy that's gone

Connecticut gas utilities have little dedicated federal or surcharge funding for distribution. Recovery runs through the rate base — and through decisions PURA has recently made harder.

  • Rate base: CNG carried about $592 million and SCG about $738 million of regulated rate base at year-end 2023 — roughly $1.3 billion combined, the asset base every capital dollar must earn a return on.2
  • LNG peaking assets: CNG and SCG together hold about 20.6 Bcf of LNG storage with peak-day delivery near 216,000 Dth — capital-intensive reliability infrastructure that must be maintained regardless of throughput trends.2
  • The hookup subsidy is gone: the ratepayer-funded incentives that financed new gas connections under the 2013 expansion program were cut short in 2022, removing a growth-capital pathway utilities had counted on.7
  • No GSEP/DSIC: without an automatic infrastructure-replacement surcharge, accelerated main replacement is recovered through contested base-rate cases — making the timing and sizing of each filing a capital-planning decision in itself.10

Where Invizion Fits

Turn Connecticut's gas-system decisions into a defensible capital plan

Invizion is scenario-based capital portfolio optimization built for utilities. When a replacement mandate accelerates, throughput forecasts shift, or a decarbonization ruling lands, you don't re-plan by hand for weeks — you model it and decide with a record to stand behind.

1

Model the “what-if” before it's forced on you

A faster main-replacement schedule, a gas-line-extension ban, an RNG mandate — build the scenario and see the impact on the whole portfolio, side by side with today's plan.

2

Re-sequence 500 projects in a click

When priorities move, Invizion re-orders the portfolio automatically — accelerating, stretching, or deferring projects against the constraints you set, not weeks of spreadsheet surgery.

3

Give regulators or your board a defensible record

Every prioritization and trade-off is captured. When you're asked “why this project, why now,” the answer is documented — not reconstructed after the fact.

Connecticut's Gas Sector, In Brief

Questions Connecticut gas leaders are asking

Short, sourced answers — the same facts we dig into with utilities looking at their capital programs.

How many natural gas customers does Connecticut have?
About 663,586 gas consumers in 2024, roughly 597,512 of them residential.1 They are served mainly by three investor-owned LDCs — Connecticut Natural Gas, Southern Connecticut Gas and Eversource's Yankee Gas — plus the municipal Norwich Public Utilities.2512
Is Connecticut expanding or shrinking natural gas use?
Shrinking, in policy terms. The 2013 program to expand gas hookups fell far short and its subsidies were cut in 2022,7 and state law now targets a 45% emissions cut below 2001 levels by 2030 and net zero by 2050, steering buildings toward electric heat pumps.4
Why are Connecticut's winter energy costs so high?
New England draws about 55% of its electricity from natural gas but has limited pipeline capacity, so on cold days gas goes to heating first and the grid leans on oil and imported LNG.3 Connecticut generated nearly 44.8 million MWh in 2024 with natural gas as its primary fuel, so gas supply and price drive both heating and power bills.14 Residential gas prices reached $18.88 per thousand cubic feet in 2023.8
Who regulates gas rates in Connecticut?
The Public Utilities Regulatory Authority (PURA) sets rates for the investor-owned LDCs.13 Its 2024 decision proposing cuts to CNG and SCG rates — which Avangrid appealed — shows how contested capital recovery has become.1011 Norwich Public Utilities, being municipal, sets its own rates.12
How does Connecticut recover gas infrastructure investment?
Mostly through base-rate cases. Connecticut has no Massachusetts-style GSEP surcharge or automatic DSIC for gas, so main-replacement and integrity spending is folded into contested general rate cases against the utilities' roughly $1.3 billion combined CNG/SCG rate base.210
How does Invizion help Connecticut gas utilities plan capital?
Invizion is scenario-based capital portfolio optimization for utilities. It lets a Connecticut LDC model how a declining-throughput forecast, a disallowed rate increase, or an accelerated cast-iron replacement mandate reshuffles the entire project list, re-sequence the portfolio automatically against its constraints, and keep a defensible record of every trade-off for PURA.

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About the Author

GB

Guy Barlow

President, Invizion

Guy Barlow leads Invizion, a capital lifecycle management platform for water and wastewater utilities. He has spent two decades at the intersection of utility capital programs, funding, and analytics, helping utilities make faster, more defensible capital decisions.

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Invizion helps utilities model, optimize, and defend their capital programs. Explore how it works, or read our latest thinking on capital planning across the utility sector.

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This briefing was last reviewed September 2026.

Sources

  1. U.S. Energy Information Administration — Connecticut Natural Gas Number of Consumers by sector (663,586 total; 597,512 residential), 2024. www.eia.gov
  2. AVANGRID, Inc. Form 10-K (fiscal year 2023) — Connecticut Natural Gas (187,790 customers, 3,871 miles, $592M rate base) and Southern Connecticut Gas (208,601 customers, 4,242 miles, $738M rate base); combined 20.6 Bcf LNG storage. www.sec.gov
  3. ISO New England — Resource Mix / Key Stats: natural gas ~55% of 2025 New England generation; winter gas-supply constraints and LNG reliance. www.iso-ne.com
  4. Connecticut DEEP — Climate Change / Global Warming Solutions Act targets: 45% below 2001 by 2030, 65% by 2040, zero-carbon electricity by 2040, net zero by 2050. portal.ct.gov
  5. Eversource Energy Form 10-K (fiscal year 2025) — Yankee Gas Services Company (Eversource Gas of Connecticut): ~256,000 customers in 85 towns; PURA-approved distribution rate case effective November 2025. www.sec.gov
  6. U.S. Energy Information Administration — Connecticut Natural Gas deliveries by sector (residential ~47,637 MMcf; total delivered ~299,410 MMcf), 2024. www.eia.gov
  7. CT Examiner — "Far Short of Goals, Connecticut Cuts Short Subsidies for Natural Gas Hookups," March 28, 2022. ctexaminer.com
  8. U.S. Energy Information Administration — Connecticut Natural Gas Residential Price ($18.88/Mcf in 2023; $16.83/Mcf in 2024). www.eia.gov
  9. CT Examiner — "New England Turns to Oil During Deep Freeze, Lawmakers Disagree on Fix," January 28, 2026. ctexaminer.com
  10. CT Examiner — "Regulators Propose Rate Cuts as Gas Utilities Push for First Hike in 5 Years," October 11, 2024. ctexaminer.com
  11. CT Examiner — "Avangrid's Gas Utilities Appeal Rate Cut in Superior Court," December 20, 2024. ctexaminer.com
  12. Norwich Public Utilities — municipal utility (est. 1904) providing natural gas, electricity, water and wastewater to the City of Norwich. www.norwichpublicutilities.com
  13. Connecticut Public Utilities Regulatory Authority (PURA) — regulates rates and services of Connecticut's electricity, natural gas, water and telecom companies. portal.ct.gov/pura
  14. U.S. Energy Information Administration — Connecticut Electricity Profile: ~44,761,412 MWh total net generation in 2024; natural gas the primary generation fuel. www.eia.gov