Potential Constrained Areas
Under the Market Rules (Chapter 7, Section 22.10), the IESO is provided discretion to designate one or more areas of the IESO-controlled grid as potential constrained area (PCA). Market Manual 14.1, Section 2.1 further specifies the process under which the IESO may designate PCAs.
The PCA designations are as follows:
| PCA name | Element name and type | Publication date | PCA start date | PCA end date |
|---|---|---|---|---|
|
CA_BLIP_2026_11 |
Interface: Buchanan Longwood Input (BLIP)
Resources: BRIGHTONCGS-LT.AG1-1B BRIGHTONCGS-LT.G1A CARTERCGS-LT.AG12 EASTWCGS-LT.G1 EASTWCGS-LT.G2 EASTWCGS-LT.G3 GSPC-LT.G3 LAUZON-LT.AG_EBUS LAUZON-LT.AG_JBUS LEAMINGTON-LT_GENSET NELSONCHP2-LT.TG PSU_GREENFIELD-LT.G1 PSU_GREENFIELD-LT.G2 PSU_GREENFIELD-LT.G3 PSU_GSPC-LT.G1 STCLAIRCGS-LT.AG_T3 STCLAIRCGS-LT.AG_T4 TASARNIA-LT.G861 TASARNIA-LT.G871 TASARNIA-LT.G881 TASARNIA-LT.G891 TAWINDSOR-LT.AG12 TILBURYBESS-LT.BATT_TG1 TILBURYBESS-LT.BATT_TG2 WALKERBESS4-LT.BATT_TG WALKERBESS5-LT.BATT_TG WALKERBESS6-LT.BATT_TG WESTWINDSOR-LT.AG12 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_CLAN_2026_11 |
Interface: Claireville North (CLAN)
Resources: AGUASABON-LT.AG12 ALEXANDER-LT.AG_T1 ALEXANDER-LT.AG_T2 ALEXANDER-LT.AG_T3 ALEXANDER-LT.AG_T4 ANDREWS-LT.AG12 ANDREWS-LT.G3 APIROQFALLS-LT.AG4 ATIKOKAN-LT.G1 AUBREYFALLS-LT.G1 AUBREYFALLS-LT.G2 CAMERONFALLS-LT.AG17 CAMERONFALLS-LT.AG234 CAMERONFALLS-LT.AG56 CANYON-LT.AG145_A CANYON-LT.G2_A CANYON-LT.G3_A CARIBOUFALLS-LT.AG123 CLERGUE-LT.G1 CLERGUE-LT.G2 CLERGUE-LT.G3 COCHRANECGS-LT.G2 DAWATSON-LT.AG123 DAWATSON-LT.AG456 DESJOACHIMS-LT.AG12 DESJOACHIMS-LT.AG34 DESJOACHIMS-LT.AG56 DESJOACHIMS-LT.AG78 EARFALLS-LT.AG1234 GARTSHORECGS-LT.G1 HARMON-LT.AG12_B HARMON-LT.G3 HARRIS-LT.G1 HOGGCGS-LT.G1 HOLDEN-LT.AG1234 HOLDEN-LT.AG5678 HOLINGSWTH-LT.G1 KIPLING-LT.AG12_B KIPLING-LT.G3 LITTLELONG-LT.AG12_B LITTLELONG-LT.G3 LOWERNOTCH-LT.AG12 MACKAYCGS-LT.AG12 MACKAYCGS-LT.G3 MANITOUFALLS-LT.AG12345 MISSIONFLS-LT.G1 NIPIGONGS-LT.G1 NORTHBAYGS-LT.AG12 NPIROQFALLS-LT.AG123 NPKIRKLAND-LT.AG123 NPKIRKLAND-LT.AG45 NPKIRKLAND-LT.G6 OTTERRAPIDS-LT.AG_115_A OTTERRAPIDS-LT.AG_230_A PINEPORTAGE-LT.AG12 PINEPORTAGE-LT.AG34 RAYNER-LT.AG12 REDROCK-LT.AG12 SILVERFALLS-LT.G1 SMOKYFALLS-LT.AG12 SMOKYFALLS-LT.G3 STEEPHILLF-LT.G1 TUNISGS-LT.G1 TWINNEY1-LT.BATT_TG TWINNEY2-LT.BATT_TG WELLS-LT.G1 WELLS-LT.G2 WHITEDOG-LT.AG123 YORKBESS-LT.BATT_TG YORKCGS-LT.G1 YORKCGS-LT.G2 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_EWTW_2026_11 |
Interface: East-West Transfer West (EWTW) Mississagi West (MISSW) Flow North (FN) Claireville North (CLAN)
Resources: AGUASABON-LT.AG12 ALEXANDER-LT.AG_T1 ALEXANDER-LT.AG_T2 ALEXANDER-LT.AG_T3 ALEXANDER-LT.AG_T4 ATIKOKAN-LT.G1 CAMERONFALLS-LT.AG17 CAMERONFALLS-LT.AG234 CAMERONFALLS-LT.AG56 CARIBOUFALLS-LT.AG123 EARFALLS-LT.AG1234 MANITOUFALLS-LT.AG12345 NIPIGONGS-LT.G1 PINEPORTAGE-LT.AG12 PINEPORTAGE-LT.AG34 SILVERFALLS-LT.G1 WHITEDOG-LT.AG123 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_FIO_2026_11 |
Interface: Flow Into Ottawa (FIO)
Resources: TAOHSC-LT.AG2012 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_FN_2026_11 |
Interface: Flow North (FN) Claireville North (CLAN)
Resources: AGUASABON-LT.AG12 ALEXANDER-LT.AG_T1 ALEXANDER-LT.AG_T2 ALEXANDER-LT.AG_T3 ALEXANDER-LT.AG_T4 ANDREWS-LT.AG12 ANDREWS-LT.G3 APIROQFALLS-LT.AG4 ATIKOKAN-LT.G1 AUBREYFALLS-LT.G1 AUBREYFALLS-LT.G2 CAMERONFALLS-LT.AG17 CAMERONFALLS-LT.AG234 CAMERONFALLS-LT.AG56 CANYON-LT.AG145_A CANYON-LT.G2_A CANYON-LT.G3_A CARIBOUFALLS-LT.AG123 CLERGUE-LT.G1 CLERGUE-LT.G2 CLERGUE-LT.G3 COCHRANECGS-LT.G2 DAWATSON-LT.AG123 DAWATSON-LT.AG456 EARFALLS-LT.AG1234 GARTSHORECGS-LT.G1 HARMON-LT.AG12_B HARMON-LT.G3 HARRIS-LT.G1 HOGGCGS-LT.G1 HOLDEN-LT.AG1234 HOLDEN-LT.AG5678 HOLINGSWTH-LT.G1 KIPLING-LT.AG12_B KIPLING-LT.G3 LITTLELONG-LT.AG12_B LITTLELONG-LT.G3 LOWERNOTCH-LT.AG12 MACKAYCGS-LT.AG12 MACKAYCGS-LT.G3 MANITOUFALLS-LT.AG12345 MISSIONFLS-LT.G1 NIPIGONGS-LT.G1 NORTHBAYGS-LT.AG12 NPIROQFALLS-LT.AG123 NPKIRKLAND-LT.AG123 NPKIRKLAND-LT.AG45 NPKIRKLAND-LT.G6 OTTERRAPIDS-LT.AG_115_A OTTERRAPIDS-LT.AG_230_A PINEPORTAGE-LT.AG12 PINEPORTAGE-LT.AG34 RAYNER-LT.AG12 REDROCK-LT.AG12 SILVERFALLS-LT.G1 SMOKYFALLS-LT.AG12 SMOKYFALLS-LT.G3 STEEPHILLF-LT.G1 TUNISGS-LT.G1 WELLS-LT.G1 WELLS-LT.G2 WHITEDOG-LT.AG123 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_KLL_2026_11 |
Interface: Kirkland Lake Load (KLL)
Resources: NPKIRKLAND-LT.AG123 NPKIRKLAND-LT.AG45 NPKIRKLAND-LT.G6 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_LENNOX_TR_2026_11 |
Interface: Lennox Autotransformer Transfer (LATT)
Resources: DESTEC-LT.G2 DPNTMTLND-LT.G1 LENNOX-LT.G1 LENNOX-LT.G2 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_MISSW_2026_11 |
Interface: Mississagi Flow West (MISSW) Flow North (FN) Claireville North (CLAN)
Resources: AGUASABON-LT.AG12 ALEXANDER-LT.AG_T1 ALEXANDER-LT.AG_T2 ALEXANDER-LT.AG_T3 ALEXANDER-LT.AG_T4 ANDREWS-LT.AG12 ANDREWS-LT.G3 ATIKOKAN-LT.G1 AUBREYFALLS-LT.G1 AUBREYFALLS-LT.G2 CAMERONFALLS-LT.AG17 CAMERONFALLS-LT.AG234 CAMERONFALLS-LT.AG56 CARIBOUFALLS-LT.AG123 CLERGUE-LT.G1 CLERGUE-LT.G2 CLERGUE-LT.G3 DAWATSON-LT.AG123 DAWATSON-LT.AG456 EARFALLS-LT.AG1234 GARTSHORECGS-LT.G1 HARRIS-LT.G1 HOGGCGS-LT.G1 HOLINGSWTH-LT.G1 MACKAYCGS-LT.AG12 MACKAYCGS-LT.G3 MANITOUFALLS-LT.AG12345 MISSIONFLS-LT.G1 NIPIGONGS-LT.G1 PINEPORTAGE-LT.AG12 PINEPORTAGE-LT.AG34 SILVERFALLS-LT.G1 STEEPHILLF-LT.G1 WELLS-LT.G1 WELLS-LT.G2 WHITEDOG-LT.AG123 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
|
CA_P502X_N_2026_11 |
Interface: Porcupine Northbound (P502X)
Resources: APIROQFALLS-LT.AG4 CANYON-LT.AG145_A CANYON-LT.G2_A CANYON-LT.G3_A HARMON-LT.AG12_B HARMON-LT.G3 KIPLING-LT.AG12_B KIPLING-LT.G3 LITTLELONG-LT.AG12_B LITTLELONG-LT.G3 NPIROQFALLS-LT.AG123 OTTERRAPIDS-LT.AG_230_A SMOKYFALLS-LT.AG12 SMOKYFALLS-LT.G3 TUNISGS-LT.G1 |
Sep 30, 2026 |
Nov 16, 2026 |
N/A |
| PCA name | Element name and type | Publication date | PCA start date | PCA end date |
|---|---|---|---|---|
|
CA_MMW_202512 |
Interface: MMW Resources: CARIBOUFALLS-LT.AG123 EARFALLS-LT.AG1234 MANITOUFALLS-LT.AG12345 WHITEDOG-LT.AG123 |
Dec 1, 2025 |
Jan 15, 2026 |
Nov 15, 2026 |
|
CA_TWM_NEW_202512 |
Interface: TWM_NEW Resources: ATIKOKAN-LT.G1 CARIBOUFALLS-LT.AG123 EARFALLS-LT.AG1234 MANITOUFALLS-LT.AG12345 WHITEDOG-LT.AG123 |
Dec 1, 2025 |
Jan 15, 2026 |
Nov 15, 2026 |
|
CA_BLIP_202512 |
Interface: BLIP Resources: BRIGHTONCGS-LT.AG1-1B BRIGHTONCGS-LT.G1A CARTERCGS-LT.AG121 EASTWCGS-LT.G1 EASTWCGS-LT.G2 GSPC-LT.G3 LAUZON-LT.AG_EBUS LAUZON-LT.AG_JBUS LEAMINGTON-LT_GENSET NELSONCHP2-LT.TG PSU_GREENFIELD-LT.G1 PSU_GREENFIELD-LT.G2 PSU_GREENFIELD-LT.G3 PSU_GSPC-LT.G1 STCLAIRCGS-LT.AG_T3 STCLAIRCGS-LT.AG_T4 TASARNIA-LT.G861 TASARNIA-LT.G871 TASARNIA-LT.G881 TASARNIA-LT.G891 TAWINDSOR-LT.AG12 TILBURYBESS-LT.BATT_TG1 TILBURYBESS-LT.BATT_TG2 WALKERBESS4-LT.BATT_TG WALKERBESS5-LT.BATT_TG WALKERBESS6-LT.BATT_TG WESTWINDSOR-LT.AG12 |
Dec 1, 2025 |
Jan 15, 2026 |
Nov 15, 2026 |
1 As per s.22.10.1.4 of Ch.7, the resource CARTERCGS-LT.AG12 was added after the initial publication of CA_BLIP_202512 and has a publication date of July 6, 2026 and PCA start date of July 8, 2026.
The IESO performed a preliminary analysis of Potential Constrained Areas (PCAs) based on historical constraint data observed after the first three months of the new market launch. This information is made available as per the implementation plan. These PCAs are not an official designation and are posted below for informational purposes only.
| PCA name | Element name and type | Publication date | PCA start date | PCA end date |
|---|---|---|---|---|
|
CA_TWM_202508 |
Interface: TWM Resources: ATIKOKAN-LT.G1 EARFALLS-LT.AG1234 MANITOUFALLS-LT.AG12345 WHITEDOG-LT.AG123 |
Aug 18, 2025 |
N/A |
N/A |
|
CA_BLIP_202508 |
Interface: BLIP Resources: BELLERVRWF-LT.AG_T1 BRIGHTONCGS-LT.G1A DILLON-LT.AG_T1 EASTLAKESCWF-LT.AG_T1 EASTWCGS-LT.G1 EASTWCGS-LT.G2 ERIEAU-LT.AG_T1 GOSFIELD-LT.AG_T1 LANDONWF-LT.AG_T1 NELSONCHP2-LT.TG NKENT1WF-LT.AG_T1 PAROCHES-LT.AG_T1 PTBURWELL-LT.AG1 RAILBEDWF-LT.AG_SR SILVERCRKSF-LT.AG_T1 SPENCECGS-LT.AG_T1 STCLAIRCGS-LT.AG_T3 STCLAIRCGS-LT.AG_T4 TASARNIA-LT.G861 TASARNIA-LT.G871 TASARNIA-LT.G881 TASARNIA-LT.G891 TAWINDSOR-LT.AG12 WALKERBESS4-LT.BATT_TG WALKERBESS5-LT.BATT_TG WALKERBESS6-LT.BATT_TG WINDSORSF-LT.AG_T1 |
Aug 18, 2025 |
N/A |
N/A |