EAM.4:11 - SoTA-Echoing

Choose the least burdensome supported comparison that distinguishes the asset options. C.16 supplies measurement and uncertainty distinctions; OPS.1 supplies the service and commitment account. North’s known 1,100 m³/h requirement already exposes a 100 m³/h shortfall. A more accurate annual average would not resolve that peak-service question.

The Environment Agency, Natural Resources Wales and Ofwat’s Water resources planning guideline, updated 16 June 2026, §§6.1 and 6.4.1–6.4.3, develops component demand, the observed baseline, critical periods and assumptions before additional measures. EAM adapts that contribution in the component reconciliation and driver construction above. The Westbank case shows why a changed driver or proposed reduction changes the asset comparison. Its values and arithmetic are constructed here.

A full specialist forecast is preferable when the relevant dependencies or uncertainty cannot be supported by that small construction. Request its result for the actual asset boundary and decision horizon. Reopen the method choice when new observations invalidate a driver or range, a changed period reveals a consequential peak, or the decision needs a fuller forecast. The water-planning source’s jurisdictional duties and planning horizon remain with that source.