5. River Exe Case Study

Describe the physical characteristics of the River Exe?

• Elevations ranging from 514 m in the north to 26 m in the south → significant topographical variation.

• The River Exe flows for 82.7 km from Exmoor to Exmouth → high drainage density and extensive tributaries.

Describe the geology and land use of River Exe?

• While 67% of the geology is grassland this is underlain by predominantly Devonian sandstones geology → 84.4% of the catchment underlain by impermeable rocks reducing percolation

• 3% of the area is moors and peat bogs which reduce runoff

Describe the hydrograph at River Exe and use figures to back it up?

The hydrograph is flashy with short lag times

Runoff constitutes 65% of the water budget indicating rapid water flow

Slow response to rainfall may be because the area is rural

Explain the Wimbleball Reservoir?

• Constructed in 1979

• Regulates water flow and supplies water to Exeter and East Devon

• Surface area of 150 hectares

• Mitigates flood and drought risks stabilizing discharge throughout the year

What are the aims of the Exmoor Mires Project?

• Restore 2000 hectares of Exmoor to peat

• Enhancing water storage in upper catchments

• Enhance peat as a carbon store encouraging CO2 absorption from the atmosphere

What did the Exmoor Mires project achieve?

• Improved water quality because the slower throughflow reduces sediment transported into rivers → saves money on treating the water and is better for animals

• Educational, leisure, and recreational opportunities are improved through the restoration of biodiverse peatland habitats → eg: guided walks, hiking, increased biodiversity

• Created a broader movement to restore peatlands across the UK addressing environmental degradation

• By 2015, 1000 hectares of peatland were restored

What are the environmental benefits of the Exmoor Mires project?

• Improved water quality, which benefits local ecosystems and wildlife, particularly fish species like salmon.

• Increased carbon storage in re-wetted peatlands contributes to climate change mitigation by absorbing atmospheric CO2.

• Biodiversity improved due to the restoration of natural habitats.

• The project enhances the resilience of the local environment against climate extremes, such as droughts and floods.

What are the economic and social benefits of the Exmoor Mires project?

• Reduced water treatment costs due to improved water quality as slower throughflow reduces sediment transported into rivers

• Enhanced recreational opportunities eg: hiking in restored peatlands can boost local tourism and community engagement → positive multiplier effect for economy

• Improved grazing conditions for livestock can lead to better agricultural productivity in the region.

• Educational initiatives stemming from the project promote awareness of peatland conservation and its importance in the water cycle.