Colorado natural gas case study, Denver, Colorado. October 2026

Denver-area natural gas capacity: the utility says a supply project is needed, and the Commission declined to certify it

Public Service said its Speer Canal Interconnects Project, along the Front Range, is needed to address forecasted supply constraints on its Denver and Northern Gas Systems and the anticipated closure of a supply point in the 2027 timeframe. The Colorado Public Utilities Commission (PUC) declined a certificate for every component of the project in a decision adopted in April 2026, for lack of adequate support, and named a path forward through an updated application.

-25 degrees FPublic Service's Design Day temperature for its Denver weather zone, per Public Service
$42.7 millionEstimated cost of the Speer Canal Interconnects Project, of $127.5 million in capacity expansion spending, per Public Service
May 2027The estimated in-service date Public Service gave for the project before the Commission declined the certificate
400 MWNew Company-owned gas combustion turbines the project would also support, location not stated in the decision

By Sam Strong, Vice President of Business Development, Discovery Energy. Technical review by Tara Dugger, Chief Operating Officer. Updated .

Metro used: the Denver-Aurora-Centennial, CO metropolitan statistical area, as delineated in OMB Bulletin No. 23-01 (July 21, 2023): Adams, Arapahoe, Broomfield, Clear Creek, Denver, Douglas, Elbert, Gilpin, Jefferson and Park counties. The principal gas distribution utility in the record is Public Service Company of Colorado (Public Service), which does business as Xcel Energy. Its 2025-2030 Gas Infrastructure Plan covers the whole company and names projects in Greater Denver, Centennial, Thornton and Aurora, so the project figures below are the most local the record has and are labeled by their geography. Atmos Energy, Black Hills Energy and Colorado Natural Gas also serve parts of Colorado; which of them serve parts of the ten counties is not established here.1

Key takeaways

  • Public Service said its Speer Canal Interconnects Project, which it describes as five interrelated projects with an estimated total of $42.7 million, is needed to address forecasted supply constraints on its Denver and Northern Gas Systems and the anticipated closure of Supply Point A in the 2027 timeframe.34
  • The Colorado PUC said in a decision adopted April 15, 2026; issued and effective June 4, 2026, that it declined to grant a certificate for all components of the project at this time for lack of adequate support in the plan filing; it said Public Service must provide additional data to document and justify the need before a certificate is granted.4
  • Public Service's table shows the project needed in 2026 under its Base forecast, and Public Service said the project is required under all of its forecast scenarios; its own estimated in-service date, before the decision, was May 2027.34
  • Public Service said that on numerous occasions the gas from Supply Point A has not met its gas quality specifications, so the gas was not accepted into its Northern Gas System and it used supply from other points; the decision gives no dates for these occasions.4
  • Public Service said its capacity planning adds no reserve margin of capacity on a pipe by pipe or regional basis, and its plan text gives no design-day demand compared with capacity for the Denver system, so the margin on the coldest day is not established.2
  • The decision says the project would also support gas demand for the operation of 400 MW of new Company-owned gas combustion turbines, and that a $9.7 million electric generation component of the project would be covered by Public Service's electric operations; EIA's September 2026 generator inventory lists no planned gas-fired generator in the ten metro counties.59

Which parts of the record fall inside the Denver metro?

Public Service's table of capacity expansion projects places the Speer Canal Interconnects Project in the Greater Denver Area, the F-715 reinforcement at Centennial (Arapahoe County), the F-866 reinforcement at Thornton (Adams County) and the Ute Highway reinforcement at Longmont (Boulder County). Its plan places the F-3 project and a non-pipeline alternative for about 1,600 customers in Aurora. Public Service said its Denver, Northern Colorado, Mountain, Pueblo and Western gas systems are physically interconnected but each operates as an independent system on Design Day.13

Where Item in the record
Inside the metro Speer Canal Interconnects (Greater Denver Area; Denver and Northern Gas Systems), F-715 (Centennial), F-866 (Thornton), F-3 and its non-pipeline alternative (Aurora)
Outside the metro, system context Ute Highway reinforcement (Longmont, Boulder County); Louisville to Rollins Pass; the Mountain Energy Project and the Eastern Mountain Gas System
Unclear Atmos Energy, Black Hills Energy and Colorado Natural Gas service in Douglas, Elbert, Park, Clear Creek and Gilpin counties

Items in Public Service's 2025-2030 Gas Infrastructure Plan and the Commission's decision, by whether they fall inside the Denver metro (OMB delineation). Source: Attachment JJP-1, Table 22; Decision No. C26-0371.1

System context: the Northern Gas System and the Eastern Mountain Gas System also serve places outside the ten metro counties, and the plan does not allocate system figures to them.

How much spare gas capacity does Denver have on the coldest day?

Major natural gas pipelines serving Denver N CIG CIG Other transmission pipelines in the EIA layer (interstate and intrastate; unlabeled) Pipeline named in a verified claim on this page (labeled, one color each) Metro counties (boundary used on this page) Major highways (for orientation)
Figure 1. Major natural gas pipelines serving Denver. Simplified, not to scale. Discovery Energy illustration from EIA and U.S. Census data. Coastline, lakes and highways: Natural Earth (public domain).

Public Service's table of Design Day temperatures by weather zone gives its Denver zone -25 degrees F and its Mountain zone -39 degrees F, set at a 1-in-30-year level from historical minimum daily temperatures. Public Service said that a comparison using a 1-in-25-year method and data from 2001 through 2025 gives -24 degrees F for the Denver zone and would not change the need for the Speer Canal Interconnects Project. The Commission directed Public Service to update its Design Day method, using weather data from 2000 to present and a 1-in-25-year probability, a new way of estimating peak hour use and a diversity factor for regional temperature differences.24

Public Service said its capacity modeling adds no reserve margin of capacity on a pipe by pipe or regional basis. The plan's text read for this page gives no design-day demand compared with capacity for the Denver system or for the ten counties, so the margin on the coldest day is not established here and is not estimated.2

What is driving new natural gas demand?

The Commission's decision describes the Speer Canal Interconnects Project as driven, in part, by the anticipated loss of one of Public Service's major gas suppliers into the Northern Gas System, forecasted growth in peak hour load in the Northern and Denver Gas Systems, and the need to supply planned gas-fired generation. The decision says the project would support the operation of 400 MW of new Company-owned gas combustion turbines approved in Commission decisions C24-0052 and C25-0024; it gives no location or service date for them, so they are reported but do not count as a documented load with a service date.45

A search of other official records found no further documented gas load in the ten metro counties: EIA's September 2026 generator inventory lists no planned natural gas-fired generator there, and a search of Federal Register notices of the Federal Energy Regulatory Commission since January 1, 2025 found no pipeline notice naming any of the counties.9

Are upgrades arriving in time?

The project's two new supply interconnections are with Tallgrass and with CIG High Plains, and it also relocates the CIG First Creek Meter Station (the decision uses the abbreviation CIG).4 Public Service's table gives the Speer Canal Interconnects Project spending of $1.0 million in 2025, $19.3 million in 2026 and $22.4 million in 2027, and showed the project needed in 2026 under its Base forecast. Public Service said construction was expected to begin in August 2026 for an estimated in-service date of May 2027, in time for the 2027-2028 heating season.34

The Commission declined to grant a certificate for any component of the project, citing concerns about Public Service's forecasting, the support for electric generation infrastructure whose cost the electric system partly bears, and vague details on the ongoing unavailability of Supply Point A. It said the approach in the joint stipulation, an updated application under a revised CHP-Aligned forecast, could provide a path forward. The record read does not show a refiled application or a new decision, so the project is neither approved nor scheduled in the sense of Outlook Scale v2.3.4

Public Service's plan also lists a non-pipeline alternative for about 1,600 customers in Aurora, which it described as its desired plan to avoid the planned F-3 reinforcement, and said the capacity constraint behind that project remains fundamentally the same. System context: a separate certificate for the Mountain Energy Project, LNG and CNG installations for the Eastern Mountain Gas System, was granted in Decision No. C25-0840 and covers mountain towns outside the metro.34

What does this mean for business gas costs?

The Commission said it declined to approve the plan in its entirety and addressed each requested approval in turn, and it declined a presumption of prudence for the Louisville to Rollins Pass cost estimate and left its prudency to a future rate case. The decision says a $9.7 million electric generation component of the Speer Canal Interconnects Project's total would be covered by Public Service's electric operations as a transportation demand charge, according to the company. The record read gives no allocation of project costs among gas customer classes, and this page states no bill impact.4

Who gets gas first in a shortage?

Public Service said interruptible customers use available capacity, if it exists, that firm customers are not using at a specific time, and that it does not use interruptible customers' estimated peak hour load to set the capacity needed on Design Day. The tariff's interruption sequence was not read for this page.3

Winter and market context

Context only, as of October 2026. It does not set the outlook level and makes no prediction of outages. Its sources are listed separately under Market and weather sources and are refreshed on the publication date.

NOAA's Climate Prediction Center said on October 15, 2026 that its November 2026 to January 2027 temperature outlook favors above-normal temperatures for, among other areas, the western third of the contiguous United States, a discussion that names regions and not counties, and that the probability of at least a strong El Nino continuing through January to March 2027 is 80%.B1 The U.S. Energy Information Administration (EIA) said on October 6, 2026 that it expects U.S. natural gas inventories to enter the winter heating season 2% above the previous five-year average, and that prolonged periods of cold weather could increase withdrawals beyond its forecast.A1A2 EIA lists U.S. liquefied natural gas gross exports of 15 billion cubic feet per day in 2025, 18 in 2026 and 19 in 2027.A1 These are national and regional facts, not statements about the utility's system, and none of them is used to set the outlook on this page.

What is the outlook for Denver gas capacity through 2029?

Discovery Energy rates the outlook for Denver-area natural gas capacity through 2029 as Elevated (confidence: Medium): Public Service's plan says the Speer Canal Interconnects Project is needed for forecasted supply constraints, and the Commission declined to certify it while naming a path forward, so the need has no approved fix, though the records are for Public Service's Denver and Northern Gas Systems. Documented risk factors: none beyond the base level. Three developments would change the assessment: Public Service's updated application for the Speer Canal Interconnects Project and the Commission's decision on it; any notice giving the date or volume of the closure of Supply Point A; Public Service's next Gas Infrastructure Plan with its Design Day method updated as the Commission directed.

Outlook levels, from least to most concern: Stable, Watch, Elevated, High, Severe. Levels describe the public record of capacity and supply risk; confidence is reported separately. They are qualitative assessments, not forecasts of outages.

What should Denver-area facilities check now?

  • Tariffs and charges, through a utility audit. Confirm each account is on the right rate class and tariff, and that riders, demand charges and capacity-related charges are billed correctly. Over 70% of the clients Discovery Energy has audited were billed incorrectly. An audit verifies tariffs and charges and recovers overcharges before winter costs rise.
  • Which service. Confirm whether each site takes firm or interruptible service from Public Service; the plan says interruptible customers use capacity that firm customers are not using at that time.
  • Backup plans and fuel. Check that alternate-fuel and curtailment plans are current and feasible, and that fuel inventories and resupply arrangements are in place before December.
  • Upcoming proceedings. Track the Speer Canal Interconnects Project and Public Service's next Gas Infrastructure Plan, especially for sites in the Front Range corridor north of Denver.

Frequently asked questions

Will Denver businesses face natural gas shortages this winter?

The record does not show a shortage. Public Service said the Speer Canal Interconnects Project is needed to address forecasted supply constraints on its Denver and Northern Gas Systems, and the Colorado PUC declined to certify it in April 2026; this page makes no prediction about outages.

Is there spare gas capacity in the Denver area on the coldest day?

Public Service said its modeling adds no reserve margin of capacity on a pipe by pipe or regional basis, and its plan text gives no design-day demand compared with capacity for the Denver system, so the margin is not established.

Did the Colorado PUC approve Public Service's gas infrastructure plan?

The Commission said it declined to approve the plan in its entirety. For the Speer Canal Interconnects Project it declined a certificate for all components at this time for lack of adequate support, and named a path forward through an updated application.

Is new gas-fired generation driving demand in the Denver area?

The decision says the project would support gas demand for 400 MW of new Company-owned gas combustion turbines, without a location or service date. EIA's September 2026 inventory lists no planned gas-fired generator in the ten metro counties.

Who is cut first if Public Service must curtail service?

Public Service said interruptible customers use capacity that firm customers are not using at the time, and it does not size Design Day capacity on their load. The tariff's interruption sequence was not read for this page.

Related case studies

Discovery Energy publishes gas capacity case studies for other metros, using the same method and outlook scale.

All gas capacity ratings by U.S. metro

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Notes

  1. Public Service Company of Colorado, Attachment JJP-1, 2025-2030 Gas Infrastructure Plan (May 23, 2025; Colorado PUC Proceeding No. 25A-0220G), PDF 15, PDF 16, PDF 93 (Table 22) and PDF 104. Utility statements. Metro counties from metro_counties.csv; classification in denver_metro_classification.csv. The match of towns to counties is general geography, not a quotation. [DEN-01, DEN-02, DEN-20, DEN-26] ↩
  2. Same plan, PDF 95 (capacity planning, no added reserve margin), PDF 99 (Table 24) and PDF 100 (Design Day method). Utility statements. [DEN-03, DEN-04, DEN-05] ↩
  3. Same plan, PDF 93 (Table 22), PDF 95 (footnote 58), PDF 104 and PDF 112 (Table 27). The Speer Canal share of the capacity expansion total is run by code (denver_calculations.csv; illustrative): 42.7 divided by 127.5 is 33.5%, a share of dollars, not of capacity. [DEN-17 to DEN-20, DEN-23] ↩
  4. Colorado Public Utilities Commission, Decision No. C26-0371 granting in part and denying in part the application, Proceeding No. 25A-0220G (adopted April 15, 2026; issued and effective June 4, 2026), PDF 1, 6, 14, 18, 19, 56, 58 to 62, 92. Commission decision; statements of Public Service within it are utility statements, reported as such. [DEN-06 to DEN-16, DEN-21, DEN-22, DEN-36] ↩
  5. Decision No. C26-0371, PDF 59 and PDF 60 (the 400 MW of Company-owned gas combustion turbines, approved in decisions C24-0052 and C25-0024, which were not read). [DEN-15, DEN-16] ↩
  6. Not established, and left out of the page: dates of the Supply Point A gas quality occasions (the decision gives none); the identity, volume and closure date of Supply Point A; a design-day demand compared with capacity for the Denver system or the ten counties; the confidential appendices to the plan (project packets with design-day detail were filed under seal and were not obtained); Public Service's gas tariff interruption sequence and cost allocation among customer classes; and delivery-point utilization from pipeline postings (CIG and other postings were not captured; next capture about March 2027).
  7. Atmos Energy, Black Hills Energy and Colorado Natural Gas service in the outer counties: not established.
  8. R1 searches: the plan, the decision and testimony for supply events since January 1, 2020 (only the undated Supply Point A occasions were found); no pipeline critical notices or EIA weekly archive entries were captured for Colorado.
  9. EIA-860M inventory for September 2026 (Planned sheet, operator-reported planned dates), filtered to the ten metro counties by code, and a Federal Register search of FERC notices since January 1, 2025 by county phrase, both computed by code. A notice that spells a place differently would be missed. [DEN-24, DEN-25] ↩
  10. R3 not established beyond the above, and left out of the claims (searches run: EIA-860M, a Federal Register search of FERC notices by county, and the plan and decision text): Colorado Department of Public Health and Environment air permit records, the Public Service gas supply and generation interconnection records, and FERC eLibrary filings, none of which a script could save; news reports are leads only and are not claimed.

Market and weather sources

Public web sources saved and hashed on October 25, 2026. They are context, separate from the regulatory record cited in the Notes. The Climate Prediction Center issues its seasonal outlook once each month near mid-month; this section is refreshed on the publication date.

  1. A1. U.S. Energy Information Administration, press release, "EIA expects a mixed picture for winter fuel costs this year," October 6, 2026. Link ↩
  2. A2. U.S. Energy Information Administration, Short-Term Energy Outlook, October 2026 (natural gas storage). Link ↩
  3. B1. NOAA Climate Prediction Center, Prognostic Discussion for Long-Lead Seasonal Outlooks, issued October 15, 2026. Link ↩

Sources

  1. Public Service Company of Colorado (Xcel Energy), Attachment JJP-1, 2025-2030 Gas Infrastructure Plan, Proceeding No. 25A-0220G. Link
  2. Colorado Public Utilities Commission, Decision No. C26-0371, Proceeding No. 25A-0220G. Link
  3. Office of Management and Budget, OMB Bulletin No. 23-01, Revised Delineations of Metropolitan Statistical Areas, Micropolitan Statistical Areas, and Combined Statistical Areas, July 21, 2023.
  4. U.S. Energy Information Administration, EIA-860M Preliminary Monthly Electric Generator Inventory, September 2026. Link
  5. Federal Register, API search of Federal Energy Regulatory Commission notices by county. Link