State of watermain infrastructure: a Canadian case study using historic pipe break datasets
Bibliographic record
Abstract
Over the last two decades, a variety of reports have suggested that watermains in Canada are deteriorating, and break rates are increasing. However, these reports are often limited as the years of break records being utilized are brief; this paper revisits those assessments using over 45 years of break records and shows that three of the five utilities investigated are experiencing significant decreases in break rates over the past 10 years while the two other utilities are maintaining consistent break rates. These results indicate that these utilities are effectively managing their watermain infrastructure, and suggest watermain infrastructure throughout Canada may be performing better than suggested by cross-sectional survey results. Analyses indicate that on average, 22% of the watermains analyzed have exceeded the 0.125 breaks per km per year break rate threshold and may be considered for pipe replacement or rehabilitation. In particular, 50% of cast iron pipes installed post-WWII have exceeded a break rate threshold of 0.125 brks/km/year, suggesting large pipe replacement or rehabilitation of this pipe cohort is required.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.003 | 0.009 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".