Estimating flow rates of a liquid in a conduit

A method of estimating flow rates of a liquid in a conduit, the method comprising:

• a flow-estimation processor receiving one or more flow-depth measurements, each flow-depth measurement having been taken at a respective time;
• the flow-estimation processor calculating a respective estimated flow rate for each of the one or more times, wherein each respective estimated flow rate is calculated based on at least (i) the corresponding flow-depth measurement and (ii) a set of one or more flow-estimation parameters each set to a respective initial value;
• the flow-estimation processor outputting the estimated flow rates for presentation via a user interface;
• the flow-estimation processor receiving via the user interface one or more updated values, each received updated value corresponding to a respective one of the flow-estimation parameters;
• the flow-estimation processor calculating an updated estimated flow rate for each of the one or more times, wherein each respective updated estimated flow rate is calculated based on at least (i) the corresponding flow-depth measurement, (ii) the one or more received updated values, and (iii) respective initial values of any flow-estimation parameters for which no updated value was received;
• and
• the flow-estimation processor outputting the updated estimated flow rates for presentation via the user interface.