19. What factors affect securing a sustainable water supply (&/or flooding) in a named catchment?

Question 1

Wimbleball Reservoir facts:

Answer 1

1979 River Haddeo, upland tributary, dammed to create Wimbleball Reservoir.
Surface area of 150ha
Supplies water to Exeter and parts of East Devon.
Regulates water flow, flattening the regime, reducing risk of flooding or drought.

Question 2

Peatland restoration on Exmoor - Exmoor Mires Project
facts:

Answer 2

Drainage ditches have been built in the past to make peat bogs suitable for farming. However, this has increased speed of water flow to the Exe and reduced water quality carrying more silt.
As peat has dried out, decomposition has taken place, releasing CO2 and CH4.
Peat has also been dug as a fuel.
The mires project has restored peat bogs (mires) by blocking drainage ditches - aim 2000ha.
More water storage in upper catchments, ensuring steady supply of water through the year
Improved water quality - slower flow means less sediment carried to rivers, good for salmon.
More carbon storage - water content increases and returns ground to saturated, boggy conditions. This helps to keep carbon in the peat.
Improved opportunities for education, leisure, recreation.
Improved grazing and water supply for animals.
By 2020, 2750ha had been restored and 250km ditches blocked, raising water table by 2.45cm.