Dredged Material Reuse

Lekki: Match Maintenance Dredging to the Beach Sand Budget

Published 5 November 2026 Publisher IMWO Region Africa Confidence Confirmed
Lekki Port entrance buildings, container stacks and quayside cranes in a 2026 port-context photograph

FrankvEck / Wikimedia Commons, CC BY-SA 4.0; cropped. Lekki Port, 2026 context view.

Lekki's design connects maintenance dredging to the artificial beach east of the port. A 2023 study by authors at CCCC-FHDI and China Harbour describes west-to-east sand transport interrupted by the port structures, with nourishment intended to replenish the downdrift beach. Its modelled sand supply combines western deposits with material recovered from the basin and channel [1]. A dredging campaign feeding that beach needs both a navigation cut and a suitable fill supply.

Two destinations for a moving sand resource

The Infrastructure Concession Regulatory Commission's 2022 annual report records an October construction-completion certificate [3]. The owner dates full operation from 1 April 2023 [4]. Lagos Free Zone's brochure identifies the first phase as 680 m of quay with two container berths, followed by a longer quay and bulk facilities in later phases [2].

The beach needs compatible fill

In its modelled maintenance scenario, the study draws about 45% of nourishment sand from western natural deposits, with the remainder coming from basin and channel maintenance. The paper describes the natural beach as medium sand with median grain size D50 greater than 0.34 mm and recommends fill slightly coarser than the native material. It calls for screening and warns that fine, muddy fill can flatten the beach profile and contribute to renewed port siltation [1]. If only part of a navigation cut meets the beach grading, that campaign supplies less nourishment than its total dredged volume suggests. The remaining beach demand needs a suitable source or a further treatment step.

Lekki sand-budget diagram connects western deposits and basin channel dredging through material grading to the eastern artificial beach

The design study links western deposits and navigation dredging to the eastern beach through source-material grading. IMWO schematic.

IMWO original conceptual sediment-flow diagram from the 2023 Lekki design study; schematic material connections.

Evidence conclusion

Estimate the delivered nourishment quantity

The campaign estimate should carry the navigation quantity removed and the compatible fill delivered as two linked volume accounts, each with a stated measurement basis. A material schedule can connect the source cut, grading results, usable fraction, transport route and receiving beach cell. That gives the planner a basis for choosing between direct transfer, sorting and a separate nourishment source. The cost comparison then includes handling and delivery for the accepted fill; a lower excavation rate may be offset by sorting, longer transport or another mobilisation. The owner's dredging and coastal-design teams can align channel soundings with western and eastern beach profiles before fixing the campaign. The same survey record should track where material was taken and placed, then test whether the receiving profile is being maintained. The issued grading limits, placement permissions and observed source yields determine the quantities for that particular campaign.

Outstanding evidence

  • Current western-shore, channel and eastern-beach surveys and the issued nourishment programme
  • Material grading, fines and compatible yield by source cut, with approved placement and measurement bases
  • Phase-specific as-built drawings, depth datum, latest soundings and any independently evidenced expansion or marine procurement
Lekki maintenance estimate keeps navigation material removed and compatible sand delivered to the beach on explicit measurement bases

Proposed campaign accounts distinguish the navigation quantity removed from compatible nourishment delivered. IMWO schematic.

IMWO original proposed dredging and nourishment accounting diagram from the cited Lekki design-study mechanism.

Related records 1

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Sources used 4

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