Riparian setback, flood risk and starting piling without consents
Your firm is appointed to design a 180-unit apartment scheme on a 0.6 ha plot in Kiambu County. The site boundary is 18 m from the high-water mark of the Nairobi River, and part of the plot is shown on county flood maps as floodplain. The client has obtained a change-of-user approval and a county architectural approval for a 10-storey scheme with two basements. The contractor has mobilised a piling rig and proposes to start tomorrow. You discover that no NEMA environmental impact assessment licence has been issued, the Water Resources Authority has not confirmed the riparian boundary, and the geotechnical report warns of a perched water table 2.5 m below ground. The client says the county approval is 'enough to start' and that delaying will cost KES 1.2 million per week in standing charges.
1. Advise the client on the approvals and statutory consents required before piling, and rank the risks of proceeding.
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The county architectural approval is not a substitute for environmental or water-related consents. Before piling, the project needs, at minimum, confirmation of the riparian boundary and any buffer requirement from the water authority, and an environmental impact assessment licence or equivalent approval under the national environmental legislation. The EIA must assess the two basements, dewatering, flood risk, erosion, silt discharge and the effect of the development on the river corridor. A county approval that was issued without those inputs does not cure their absence.
The risks should be ranked by severity. First is a stop order or enforcement notice after mobilisation, which would expose the client to standing charges, reinstatement and possible prosecution. Second is physical risk: piling and excavation near a floodplain with a perched water table at 2.5 m can destabilise the bank, cause settlement or flood the basement during construction. Third is professional liability for the architect and engineer if drawings are issued for a development that cannot lawfully proceed. Fourth is financial: the KES 1.2 million per week delay is real, but it is smaller than the cost of demolition, fines or a failed basement.
My advice would be to suspend piling immediately, record the instruction in writing, and use the delay to complete the consents and the flood and geotechnical studies. Proceeding on the basis that county approval is enough would be a false economy.
2. What due diligence would you complete, and how would you adapt the design to the site constraints?
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Due diligence should establish four things: the legal boundary and encumbrances, the actual riparian and flood extents, the ground conditions, and the approval status. I would obtain a recent survey and beacon certificate, the title and change-of-user conditions, a river cross-section and flood-level study, a demarcation of the riparian reserve by the water authority, and a geotechnical investigation that includes permeability and bank stability. I would also check whether the county approval was based on a site plan that shows the true setback.
Design adaptation would start by moving the building footprint away from the river and out of the floodplain. The two basements are the main risk; I would test a single basement or a shallower semi-basement, and shift the podium and access away from the bank. If a basement remains, it needs a waterproofing and dewatering strategy, flood-proofing of openings, and a construction method that does not lower the water table permanently. Surface water should be managed through permeable paving, retention and controlled discharge rather than direct discharge to the river. Landscaping should stabilise the bank, not load it.
The design should be presented as a revised scheme for approval, not as a minor adjustment. If the site cannot accommodate 180 units within the consented envelope, the client should be told early and the unit mix or height reviewed.
3. The client instructs you to issue the piling setting-out drawings 'without prejudice'. How do you respond?
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I would refuse to issue setting-out drawings for construction while the statutory consents and the riparian confirmation are outstanding. 'Without prejudice' does not make an unlawful start lawful, and a setting-out drawing is an operational instruction that the contractor will rely on. Issuing it would undermine my later advice to stop and could be treated as authorisation.
I would respond in writing: summarise the missing consents, the geotechnical warning, and the client's instruction; confirm that I am not issuing construction drawings; and offer a clear route forward. That route could include completing the surveys and EIA, obtaining the water authority's position, and preparing a revised design that is not dependent on the disputed setback. I could provide drawings marked 'for study only, not for construction' if that helps the client evaluate options, but they must be clearly marked and not used for piling.
I would also notify my professional indemnity insurer if the client persists, and consider whether I can continue as architect if I am asked to certify or administer work that I believe is unlawful. The fee is not a reason to issue a drawing that creates a foreseeable risk of enforcement, flooding or collapse.