River Exe

Question 1

How long

Answer 1

82.7km

Question 2

Where

Answer 2

Devon. Source in Exmoor hills, running through Tiverton and Exeter, mouth at Exmouth

Question 3

Elevation

Answer 3

514m max, 26m min

Question 4

Drainage density

Answer 4

High

Question 5

Geology

Answer 5

84.4% catchment impermeable, mostly Devonian sandstone, extensive drainage network

Question 6

% agricultural land use

Answer 6

67%

Question 7

% moors and peat bogs

Answer 7

3%, in North

Question 8

% urban

Answer 8

0.6%

Question 9

Water balance

Answer 9

Precipitation (1295mm) = evaporation +- soil water storage (451mm) + runoff (844mm)

Question 10

High runoff

Answer 10

Impermeable bedrock, saturated soil, Exmoor drainage ditches (built when highest rainfall)

Question 11

Hydrograph

Answer 11

Slow response with slow discharge recession from lower catchment’s rural nature

Question 12

Nov 2007 discharge

Answer 12

Nationwide high rainfall, highest ever 200 m3/s discharge (normally 2-100), 45001 Exe station measures

Question 13

Wimbleball Reservoir built

Answer 13

1979, upland River Haddeo tributary dammed to 150 ha surface area reservoir

Question 14

Where does Wimbleball Reservoir supply water

Answer 14

Exeter, E Devon, transfers to Wessex water

Question 15

Wimbleball Reservoir purpose

Answer 15

Regulates water flow so discharge troughs/peaks and drought/flood less likely

Question 16

Exmoor Mires project function

Answer 16

Exmoor peatland restoration, blocks drainage ditches with peat to increase water and C storage

Question 17

Exmoor Mires project needed as

Answer 17

Peat dug for fuel, ditches dug to farm, area dried out to release CO2 and CH4

Question 18

Exmoor Mires project aims

Answer 18

Restore 2000 ha. More water storage and steady annual supply, more C stored with regrowth, biodiverse, slower throughflow so better water quality, animal grazing and water, more leisure and education opps

Question 19

2015 results

Answer 19

1000 ha+ restored, 100km ditches blocked, 2.65cm higher water table

Question 20

How are the effects measured

Answer 20

Dipwell transects from 3 experimental stations

Question 21

Results of Exmoor Mires project

Answer 21

Higher water table, less stormflow and flood peaks, more baseflow, more water storage in peat moss. Consistent with other UK and Ireland rewetted peatlands