Notable failures in tunnelling projects, construction insurance market under pressure, and reluctance to insure similar projects. That was the case with tunneling projects almost 20 years ago, and there currently seems to be a déjà vu with hydro projects. The tunnel construction insurance market came back on its feet following the issuance of the Code of Practice for Risk Management of Tunnel Works in 2003. Are we marching towards the drafting of a Code of Practice for Risk Management of Hydro Projects?

Recent catastrophic events on hydro projects have led to what are believed to be the highest claims in the history of construction insurance. Especially when Delay in Start Up (DSU) coverage is sought, makes things much more challenging. This cannot be sustainable in the industry. The future will show, but to the author’s humble opinion, the industry should promote a new guidance document for hydro projects, given the positive impact following the issuance of the Code of Practice for Risk Management of Tunnel Works. One would argue that following the principles of the existing Code, there is a robust framework of risk management that could be applied in hydro projects with dams and underground works. Indeed, but hydro schemes apart from extensive network of tunnels and caverns, may include dams, temporary cofferdams and river diversion tunnels and schemes where flood return periods must be carefully evaluated and considered, and considerably large caverns, to name a few.  The most notable difference however lies on the operational phase. Unlike the infrastructure tunnels, where the tunnel is continuously accessible during operation for visual inspection and non-destructive testing to verify its condition and validate the preventive maintenance plan, the same in not the case with water conveyance tunnels. Emptying the tunnels does not only adversely impact the revenue scheme but also introduces dynamic effects which can endanger the structural integrity of the tunnels. There is currently increasing trend in using robots for visual real-time inspection and scanning, however it does not offer the same degree of inspection effectiveness. Furthermore, fluctuations in the operational pressure may introduce stresses beyond the in situ capacity of the rockmass and collapses may occur, especially in unlined headrace tunnels.

The list can go on but, certainly, a commonly accepted guidance for risk management of hydro projects would help stabilise the flow of business after the turbulence.

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