Understand the topic
What this means in daily life
Urban flood work should follow the whole route rainwater takes. Start with the catchment: the area from which water flows toward shared drains, streams or outlets. Connect rainfall, paved surfaces, low areas, drains, storage spaces and the place where water leaves the area before assuming that every street needs a bigger drain.
The owner’s idea of finding all possible ways to reduce flooding belongs here. Develop it by comparing maintenance, safe storage, land-use changes and properly designed drainage together. Every option must consider people and places downstream, including communities outside the project boundary.
Data reference table
Evidence Snapshot
Read each value with its reporting period, population and limitations. A historical national reference is not a local baseline or proof that an IFT proposal works.
5 measurement records still need data and a review of their relevance.
| Signal | Reference Value | Period / Population | How to Read It | Source Status |
|---|---|---|---|---|
| Service coverage | Not established Data required — not zero | Reporting period: Information Required Population and geography: Information Required | Proposed measure; no observed value is established here. Limitations: Define the measure, unit, reporting period and covered population; obtain a traceable dataset and review its suitability for this topic before using a number. | Source organisation: Information Required Direct source URL: not yet verified Source publication date: not established Verification status: Data required |
| Reliability and quality | Not established Data required — not zero | Reporting period: Information Required Population and geography: Information Required | Proposed measure; no observed value is established here. Limitations: Define the measure, unit, reporting period and covered population; obtain a traceable dataset and review its suitability for this topic before using a number. | Source organisation: Information Required Direct source URL: not yet verified Source publication date: not established Verification status: Data required |
| Loss, overflow or flood duration | Not established Data required — not zero | Reporting period: Information Required Population and geography: Information Required | Proposed measure; no observed value is established here. Limitations: Define the measure, unit, reporting period and covered population; obtain a traceable dataset and review its suitability for this topic before using a number. | Source organisation: Information Required Direct source URL: not yet verified Source publication date: not established Verification status: Data required |
| Treatment and safe reuse | Not established Data required — not zero | Reporting period: Information Required Population and geography: Information Required | Proposed measure; no observed value is established here. Limitations: Define the measure, unit, reporting period and covered population; obtain a traceable dataset and review its suitability for this topic before using a number. | Source organisation: Information Required Direct source URL: not yet verified Source publication date: not established Verification status: Data required |
| Lifecycle cost and equity | Not established Data required — not zero | Reporting period: Information Required Population and geography: Information Required | Proposed measure; no observed value is established here. Limitations: Define the measure, unit, reporting period and covered population; obtain a traceable dataset and review its suitability for this topic before using a number. | Source organisation: Information Required Direct source URL: not yet verified Source publication date: not established Verification status: Data required |
Different surveys, administrative records, estimates and reporting years are not interchangeable. No combined IFT score is calculated from these rows.
Evidence coverage and review log (CSV) · Structured evidence register (JSON)
10 ideas for this topic
What could be done — and what needs testing
These are proposals for research and local testing. They are not claims that a project has been funded, implemented or proved successful.
Map the whole rainwater route
Ask drainage teams to connect upstream land, streets, drains, ponds and receiving waters on one working map. Include missing records and uncertain flow directions.
What to check: Check the full route during different conditions before deciding where to increase capacity.
A blocked-outlet repair programme
Build a prioritised list of outlets needing authorised inspection and maintenance. Give each item a named owner and a record of what was actually cleared or repaired.
What to check: Check whether the outlet can discharge safely under the relevant receiving-water conditions.
A repeat-flood location diary
Combine dated municipal records with protected resident accounts to document where water collects, when it arrives and how long access is affected.
What to check: Compare accounts with rainfall and service records; avoid treating a single image as a complete flood map.
A storage-space protection study
Identify existing ponds, wetlands and other spaces that may store water. Ask qualified teams to assess their function before considering filling, development or restoration.
What to check: Check land rights, ecology, neighbouring impacts and maintenance before proposing any change.
A safe property-level runoff trial
Invite willing public facilities to assess suitable rainwater storage or infiltration options under professional design and maintenance oversight.
What to check: Check soil, groundwater, contamination, overflow and foundation risks; do not apply one design everywhere.
A critical-access protection plan
Map routes to hospitals, shelters, schools and essential utilities. Compare options for keeping safe access during disruption with the relevant service owners.
What to check: Check whether diversions remain accessible to disabled people and do not send users into another hazard.
A downstream-impact comparison
Require each proposed diversion, pump or enlarged drain to show where the additional water would go and who may be affected.
What to check: Reject options that merely transfer unacceptable harm beyond the project boundary.
A utility-failure coordination exercise
Ask electricity, water, sanitation and transport teams to practise who acts when flooding interrupts several services at once.
What to check: Check communication, safe isolation decisions by authorised teams and support for vulnerable users.
A maintenance-funded project comparison
Compare new works with restoration and maintenance options using realistic operating responsibilities and continuing costs.
What to check: Check that the proposed owner has resources to maintain the chosen option after construction.
A rainfall-matched results review
Record disruption, recovery time, affected access and reported losses alongside rainfall and receiving-water conditions before and after the work.
What to check: Explain uncertainty; different storms should not be presented as directly equivalent tests.
References and evidence limits
- CPHEEO: Manual on Storm Water Drainage Systems (2019)
A technical reference for specialist planning, operation and maintenance review. It does not establish the condition of a local network or approve a proposed design.
Reference guidance informs the proposal. It does not establish local conditions, approve a design or prove that these proposed projects work.