Water Resource Associates
A network of consultants in water resources, water quality, hydrology, hydrogeology and flooding.
Bristol Water inflow data
The aims of the study were:
a) to provide a long term flow data base for resource analysis.
b) to provide a model for statistical prediction of the consequences of drought.
Background
Bristol Water is responsible for supplying water to over 1 million consumers in the city of Bristol and surrounding areas. Most of their resources come from reservoirs fed by rivers which rise in karstic areas the Mendip Hills. In 1993 a previous project (not by ourselves) had provided a single global inflow sequence for all reservoirs. The client wished to update the flow sequence and to have flow data for each individual source.
Chew Valley reservoir
Line of Works - elevated section
Scope of work by Water Resource Associates Ltd
Water Resource Associates ordered and quality controlled all the meteorological data needed for flow simulation. We also quality controlled data on storage and water supplied to calculate "observed" inflow for each reservoir. One particular flow sequence was unique to this project - the "Line of Works". This had been constructed in 5 separate parts, partly tunnelled and partly as an aqueduct, in the mid-nineteenth century and captured water by gravity from a number of springs.
Results
A daily flow record was prepared for each of the 7 inflows for the period 1910 to 2002 using the HYSIM rainfall/runoff model.
In addition, as part of the contract, a new feature was added to HYSIM. This allows the model to be run with different statistically derived droughts for the future. The user can choose the start date, duration and return period. This enable an assessment to made of the risk of system failure and to decide on appropriate actions.