Exploitation of new sources of water

• Rainwater collection: is important where there is no public water supply, this water is often cleaner than other sources such as rivers
• river water is often the most convenient water source
• rivers are accessible over a large land area due to its length
• river water used for domestic use may be contaminated with pathogens
• total annual water flow, flow fluctuations, level of natural contaminants, pollutants from human activities are the main features that affect the usefulness of a river
• topography affects reservoir location: ideal topography creates a narrow exit from a large deep basin so that a relatively small dam can hold back a huge volume of water
• geology affects reservoir location: rock beaneath must be impermeable, the rock must also be strong enough to support the weight of the dam and the reservoir without faults or seismic activity that could collapse the dam
• catchment area affects reservoir location: must be rain from a previous rain that can travel to the reservoir
• water supply can affect reservoir location: rainfall or rain inflow should be regular and have a large volume, climate should not be too high to prevent high evaporation rates
• Sedimentation affects reservoir location: soil erosion in the catchment area can make river inflow very turbid, resulting in sedimentation. This gradually reduces the volume of water the reservoir can hold
• Infrastructure can affect reservoir location: building the dam, treating the water require workers, building material, access routes etc. therfore the site should be near the area of demand
• a lost benefit: analysis must be considered to balance the benefits of having the reservoir against what is lost
• Estuary barrage is a freshwater reservoir created by a building a dam across an estuary where a river enters the sea
• estuary barrage has less land use conflicts than reservoirs on land required to be flooded, but they do change inter-tidal habitats, create an obstacle for shipping and can br polluted by human activities
• desalinisation is very high energy intensive and expensive