In a dry summer, a water company used the river system shown in Fig. 1 to supply a town, irrigate market gardens and maintain water in a reservoir. The diag...
Question 1 Report
In a dry summer, a water company used the river system shown in Fig. 1 to supply a town, irrigate market gardens and maintain water in a reservoir. The diagram shows that water is abstracted upstream, treated for homes, and later returned to the river through a sewage-treatment outfall. Farmers have asked for a larger abstraction licence, but anglers are concerned about low flow and poor water quality. The company collected river-flow data during its enquiry.
(a) Identify two uses of water shown in Fig. 1 and state one consequence for the river if too much water is abstracted. [4]
(b) Describe how river flow and water quality may change between the abstraction point and the downstream fishing reach during a drought. [4]
(c) Which five actions could the water company use to reduce pressure on this river resource? [5]
(d) Outline how a catchment management plan could balance the needs of households, farmers, anglers and the river ecosystem. [7]
Answer Details
(a) Uses include domestic supply to the town [1], irrigation [1], reservoir storage [1], and fishing or recreation [1]. Excess abstraction can lower river discharge or level, reduce pollutant dilution, or stress aquatic habitats. [1] Maximum [4].
(b) Flow falls after abstraction because water is removed [1], and drought lowers discharge further [1]. Treated effluent becomes a greater proportion of the water [1], so pollutants are less diluted and water quality may decline. [1] [4]
(c) Reduce pressure by repairing leaks, installing meters, reducing household demand, using drip irrigation, irrigating at cooler times, storing winter runoff, setting seasonal abstraction limits, and safely reusing treated wastewater. Any five [1] points. [5]
(d) A catchment plan should monitor flow and water quality at several points [1], set a minimum environmental flow [1], use timed or seasonal irrigation licences [1], prioritise essential household supply during drought [1], require efficiency and leak reduction [1], regulate sewage-treatment discharge [1], and involve farmers, residents and anglers in review. [1] [7]
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