clm-682de3d9f20742a5
quantitative
opened in 2007, is a 9.7 km stormwater bypass
Permanent project revision
Revision 2026-08-15-baseline · effective 2026-08-15
Superseded. A later revision exists: 2026-08-20-source-dates-b2 →
Created the first structured Evidence Passport with 12 claims and 6 source dossiers.
sha256:5da8166bfdcc56145b7c0d39c81af83ac5d4cf5699d859855b35e37b453d6b2c
add /evidencePassport — Added claim-level evidence mapping and source dossiers.add /revisionHistory — Established a permanent, hash-addressed baseline revision.The text below is copied verbatim from the published record. Each claim names the source dossiers that carry it; caveats stay attached to the claim they qualify.
clm-682de3d9f20742a5
quantitative
opened in 2007, is a 9.7 km stormwater bypass
clm-9807a168d88b157b
quantitative
carrying an average of 30,000 cars daily
clm-8d4fe1dfab1f8847
quantitative
flow at the L4 confluence of the upper Klang and Ampang rivers passes 70 cubic metres per second
clm-8fa1a2037f6051ee
quantitative
at a forecast 150 cubic metres per second the operator declares Mode 3 and evacuates the motorway in about an hour
clm-4800c11bee63c766
quantitative
Mode 4 follows one to two hours later, watertight gates open and the full bore goes to floodwater, with the road back within four days
clm-ce20b1eb25324c99
quantitative
Built for RM1.887 billion (US$514.6 million)
clm-e2e50ad937e393a5
descriptive
under an MMC–Gamuda joint venture and run day-to-day by its operating company Syarikat Mengurus Air Banjir & Terowong
clm-771d245db7aeac62
quantitative
5 million cubic metres diverted in a 22-hour operation, against a design capacity of 3 million
clm-6f019522c6d4210e
descriptive
the Masjid Jamek area in the city core would have flooded severely without the diversion
clm-824b60390082e2b9
quantitative
nine Mode 4 (full flood mode) activations between opening in May 2007 and the end of 2021
clm-f15085b18334ec2d
quantitative
averting an estimated RM1.4 billion
clm-42b8e5994021c336
quantitative
across more than 40 flood diversions
This layer records what is known about each source, what is still missing, and the exact snapshot this page is rendering. A missing date, archive or hash stays visible as missing.
Awaiting operator and domain-expert review; publication of this revision implies neither.
sha256:5da8166bfdcc56145b7c0d39c81af83ac5d4cf5699d859855b35e37b453d6b2c
src-e08835a317b33da3Operator page; the four modes, the 70–150 m³/s thresholds at the L4 confluence, ~1-hour evacuation, Mode 4 declared 1–2 hours after Mode 3, reopening within 4 days.
src-f68ce9a701a75bd0Operator page; project implemented through the MMC Corp–Gamuda joint venture pact, dual flood/traffic purpose.
src-f8b48247ff586158December 2021 record: 5 million m³ against 3 million capacity, 22-hour operation, ninth Mode 4 activation since 2007, RM1.4 billion damage averted across ~40 operations (operator statements).
src-095a1ab82b73ebb0Builder's rehost of the Star report; confirms 5 million m³, 22 hours, nine Mode 4 activations, Masjid Jamek counterfactual, SMART COO named.
src-831f7a24c944f303Independent flood-news reference: 9.7 km length, 3 million m³ capacity, RM1.887bn (US$514.6m) cost, opened 14 May 2007.
src-ca04d4a5e540682aFinancier's page naming the operating company; RM323 million financing (2004), 30,000 cars daily, 40+ diversions and estimated RM1.4 billion damage averted since 2007.