I. SPC Legal Position on Canal Dredging Contracts

The Supreme People’s Court treats canal dredging contracts as:

1. Construction engineering contracts (most inland canal cases)

Applied when:

• dredging is part of water conservancy works
• project is tied to public infrastructure
• contractor uses heavy engineering equipment

2. Maritime construction/service contracts (port & navigation channels)

Applied when:

• dredging is in navigable sea/port channels
• disputes involve port authorities or shipping impact
• cross-border or international dredging companies are involved

Core SPC principle:

Even if labeled differently, the court determines the true nature of the contract based on function, not title.

II. Core SPC Judicial Rules in Dredging Contract Disputes

Case Law 1: Contract validity does not prevent payment recovery

Rule:
Even if a dredging contract is invalid (e.g., lack of qualification or bidding defects), the contractor may still claim payment based on actual work performed.

SPC principle:

• settlement is based on actual construction value
• contract terms may be used as reference

✔ Applied under SPC Construction Contract Interpretation (2021)

Case Law 2: Completed dredging project = right to payment

Rule:
If dredging work is completed and accepted, the contractor is entitled to project payment even if disputes exist over contract legality.

Legal reasoning:

• unjust enrichment must be avoided
• acceptance acts as confirmation of performance

✔ Frequently applied in SPC retrial rulings on port dredging disputes

Case Law 3: Dredging depth/volume disputes require expert appraisal

Rule:
Where parties dispute dredged volume or depth, SPC courts require:

• third-party engineering appraisal
• hydrographic survey reports
• satellite or navigation data

Key principle:
Court will not rely solely on unilateral measurement reports.

Case Law 4: Port authority delay liability (causal link test)

Rule:
If the port authority or project owner delays dredging site handover, they bear liability only if:

• delay is proven to cause increased cost or idle equipment loss
• causal link is clearly established

Otherwise, contractor bears idle-time risk.

Case Law 5: Price adjustment allowed under changed circumstances

Rule:
SPC allows adjustment of dredging contract price when:

• sediment conditions are significantly different from contract assumptions
• underwater geology changes dredging difficulty
• government instructions alter channel design

This applies the “changed circumstances doctrine” under civil law principles.

Case Law 6: Illegal subcontracting in dredging projects

Rule:
If a dredging contract is illegally subcontracted:

• subcontract may be invalid
• but actual performer may still claim reasonable compensation

SPC emphasizes:

• protecting actual labor and construction value
• preventing unjust enrichment of main contractor

Case Law 7: Interest on delayed payment is generally supported

Rule:
In dredging disputes, if the employer delays payment:

• contractor is entitled to interest
• even if contract is partially invalid
• interest calculated based on market lending rate or agreed clause (if referenceable)

Case Law 8 (Recent SPC trend): Maritime dredging contracts follow hybrid rules

Example principle from SPC port dredging litigation:

• Port deepening projects are treated as capital construction projects
• but governed by maritime procedural rules for jurisdiction

This hybrid classification was reaffirmed in recent port dredging disputes involving large port authorities and dredging companies.

III. Key SPC Doctrinal Themes in Dredging Disputes

1. “Substance over form”

Courts ignore labels like:

• “dredging service contract”
• “lease of dredger”
  and instead classify as construction work.

2. Protection of actual builders

SPC consistently protects:

• dredging contractors
• subcontracted construction teams

Even in invalid contracts.

3. Engineering reality dominates contract wording

SPC relies heavily on:

• physical completion
• engineering appraisal
• acceptance reports

Not just contract clauses.

4. Risk allocation principle

Typical SPC allocation:

IV. Practical SPC Outcome Pattern

In most canal dredging disputes, SPC judgments follow this structure:

1. Determine contract validity
2. Confirm actual dredging work performed
3. Appraise dredging volume/cost
4. Adjust price if conditions changed
5. Award payment + interest
6. Allocate delay/efficiency risk

V. Conclusion

The Supreme People’s Court treats canal dredging contract disputes as high-value infrastructure construction cases, applying a consistent rule-set:

• actual work > contract form
• completion + acceptance = payment entitlement
• invalid contract ≠ loss of compensation rights
• engineering appraisal is decisive
• fairness and unjust enrichment prevention dominate outcomes