ESTIMATEDDate confidence: ESTIMATEDA target, not a fixed dateHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all ESTIMATED pins3 years late65% CONFIDENCEOverall confidence: 65%How well the pin's source and references back up its dates.Weighted average of how firmly 4 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins from 50% to 74% confidence
MWRD’s[2][4] August 15, 2025 release explicitly gives December 31, 2032 as the current estimate for Stage 2 going online. This day is a published estimated target, not proof of completion; Stage 1 has operated since 2017.Delayed from 12/31/2029 to 12/31/2032: 3 years later. Stated: delayed from the original 2029 deadline; "the current estimate for McCook Stage 2 going online is now Dec. 31, 2032."- Groundbreaking
- Dec 31, 203250% CONFIDENCEsource
McCook Reservoir's Second Stage Delayed to 2032
The next phase of Chicago's giant Deep Tunnel flood-control reservoir has slipped three years behind its original federal deadline because of a local stone shortage.
Construction research — October 24, 2026
McCook Stage 2 is In Progress: MWRD’s August 15, 2025 release explicitly describes active quarry excavation and a December 31, 2032 operational estimate. The native date is retained with estimated confidence; Stage 1’s 2017 operation does not complete Stage 2. The current TARP budgets mix shared Stages 1/2 works, mining and individual future preparation contracts. Neither the whole-reservoir budget nor a mining-change-order ceiling establishes a separately quoted all-in Stage 2 total.
- MWRD issues update on Tunnel and Reservoir Plan: McCook Stage 2 is an active stone quarry that is being excavated[4]
- MWRD — TARP Status Report 2024: Stages 1 and 2[2]
Earlier pin evidence
- MWRD's August 2025 release says Stage 2 of McCook Reservoir is now estimated to go online on 31 December 2032[4]
- The original consent decree (6 January 2014) required mining finished by 31 December 2028 and operation by 31 December 2029[4]
- The delay stems from slowed demand for stone: Stage 2 is an active quarry excavated by Vulcan Materials, so mining pace follows stone demand; MWRD says it has met all decree requirements and such delays were anticipated[4]
- Stage 1 was completed in 2017 with 3.5 billion gallons; Stage 2 adds 6.5 billion for 10 billion gallons total, and Stage 1 has captured about 130 billion gallons of stormwater and wastewater[3][4]
- TARP (Deep Tunnel), begun in 1972, is otherwise complete; McCook serves 3.1 million people in Chicago and 36 suburbs, with total cost projected around $1 billion, cost-shared with the Army Corps[3][4]