Hydrology and fluvial geomorphology (case studies)

Question 1

Keswick: How much rainfall occured in December 2015?

Answer 1

517.6mm record rainfall in December in Keswick, double the average December rainfall

Question 1

Keswick: Meteorological conditions in December 2015

Answer 1

• December 2015 was the wettest month on record
• December followed a particularly wet november

Question 2

Keswick: When was the date range in December when new 24hr and 48hr rainfall records were set?

Answer 2

Between the 4th and the 7th of December. The previous records were also set within Cumbria

Question 3

Keswick: Why was a wet November problematic?

Answer 3

Because much of the soil was already saturated by December, meaning there was less capacity for infiltration and the River Greta would be more likely to exceed bankful capacity

Question 4

Keswick: What was the name of the storm that occured?

Answer 4

Storm Desmond

Question 5

Keswick: Causes- drainage basin layout

(not geology)

Answer 5

• The River Greta flows through Keswick and is fed by the River Glenderamackin, and St. Johns Beck.
• There is a high drainage basin density and many smaller tributaries that feed into the river

Question 6

Keswick: Causes- Geology

Answer 6

• The Northern part of the drainage basin is mostly made up of sedimentary rocks such as sandstone, mudstone and siltstone. They are permeable and porous mostly so allow for infiltration
• However, the Southern part has impermable igneous intrusions, and despite some faults they are mostly impermeable.
• This encourages overland flow and decreases infiltration/percolation

Question 7

Keswick: Impacts - How many people were affected across which regions?

Answer 7

• An estimated 14,694 people in total were affected
• This is in the regions of Allerdale, Carlisle, Eden and South Lakeland

Question 8

Keswick: Impacts - What is noticeable about how Carlisle was impacted?

Answer 8

• In Carlisle 30% of the most deprived areas were directly affected
• 22.5% of fading owner occupied terraces (financially stretched category) were affected by the flooding in the Carlisle area.

Question 9

Keswick: Impacts - How much of the damage to highways was classed as “significant”

Answer 9

56% of the 354.8km of affected highway was classed to be “significantly damaged”

Question 10

Keswick: Impacts - How much was paid out from Community Foundation flood appeal?

Answer 10

£3.86 million, with the majority of this being for flood defences

Question 11

Keswick: Defences - When was the “Flood Risk Management scheme” put into place?

Answer 11

In 2011/2012

Question 12

Keswick: Defences- As part of the FRMS what was put into place on Penrith Road?

(Did it work in ‘15?)

Answer 12

• A Stone-clad concrete defence wall and flood gate was implemented
• This proved ineffective in coping with the 2015 floods as the Penrith Road area became inundated with water and cut off this crucial access route

Question 13

Keswick: Defences - name all the hard engineering solutions of the FRMS
(Spoiler: 2015 floods overpowered all of them)

Answer 13

• Penrith road concrete flood defence wall
• Drainage holes
• Stone clad reinforced concrete wall with glass panels to retain visibility of the river at High Hill

Question 14

The government has tasked the environmental agency with delivering (WHAT AMOUNT) in flood defences across the UK since 2015?

Answer 14

After the flood of 2015, the government has allocated £2.6 Billion to the Environmental Agency to distribute across the UK.

Question 15

Keswick: How many homes and businesses were flooded?

Answer 15

730

Question 16

Keswick: What recent target has been exceeded by the environmental agency?

Answer 16

It has exceeded its target of protecting 300,000 homes across the UK from flooding, with thousands of these homes being in Cumbria

Question 17

Keswick: How much has the Carlisle Flood Risk Management Scheme cost?

Answer 17

£25 million

Question 18

Keswick: How many properties will be protected by the Carlisle Flood Risk Management scheme?

Answer 18

1,200 homes and 106 businesses

Question 19

Keswick: How will the Carlisle Flood Risk Management Scheme protect residents and businesses?

Answer 19

• By raising and extending flood walls
• Improving the flow of water through Botcherby Bridge to allow a greater volume of water to pass through during a flood.

Question 20

Keswick: Evaluating short term responses - how was communication with residents during the event?

Answer 20

• The Environment Agency contacted KFAG (Keswick flood action group) to raise awareness
• The Environment Agency also sent messages to stakeholders via the Cumbria Community Messaging (CCM) system

Question 21

Keswick: How many survey respondents said they heard about the “flood fund” for financial assistance after the flood in good time?

Answer 21

80% of those who’s property was damaged

Question 22

Keswick: How many applicants to the flood fund recieved all the money they applied for?

Answer 22

76% of applicants

Question 23

Keswick: Evaluating short term responses- what action was taken to help those immediately affected?

Government help + Local people help

Answer 23

• 200 military personnel
• 50 high volume pumps
• A chinook helicopter deployed
• £400,000 donated by the public within 48 hours

Question 24

Keswick - Why was Storm Desmond so severe?

Answer 24

An “atmospheric river” bringing moist air from the Carribean to Britain and an area of low pressure

Question 25

EXAMPLE: Deltas

Answer 25

The Nile delta - arcuate delta
The Tiber delta (Tyrrhenian sea) - Cuspate delta
The Mississippi delta - birds foot delta

Question 26

Keswick: How many sheep are there and why is this a problem?

Answer 26

• There are 50,000 sheep in Keswick
• These sheep trample the land and compact the soil, closing gaps within the soil which would have aided with infiltration

Question 27

Keswick: Land use types

Answer 27

• Largely pastoral land, the herdwick sheep species is particularly prevalent
• In Keswick the tourism industry is key and this urbanisation has also impacted in infiltration

Question 28

Keswick: Short term responses to reduce further flood damage

Actions taken by Local government in the short term.

Answer 28

• 4th December: Closed 3 floodgates and inspected watercourse structures for any blockages
• 5th December: Supplied a community pump to try and return flooding on Penrith Road back to the river
• The EA started emergency works to remove 25,000 tonnes of gravel from the river Greta to increase channel capacity
• Used the Cumbria Comunity Messaging system and worked with the KFAG to communicate with those at risk

Question 29

Keswick: how much did the glass panelled defence wall at High Hill cost and when was it installed?

Answer 29

• Cost £6 million
• Installed after the severe floods of 2009

Question 30

What were the environmental impacts of Storm Desmond/keswick flooding?

Answer 30

• In Cumbria, Desmond + flooding caused £185k of damage to forestry assets
• South Lakeland also experienced landslides and river erosion at Kirkby Lonsdale
• Some Mature parkland trees were lost
• Leaking fuel tanks, mainly
  heating oil, were reported in the Eden district, and an oil spillage at Mintsfeet,

Question 31

Keswick: Reservoir use

Answer 31

• Hard engineering method
• Thirlmere reservoir managed by United Utilities was designed to hold excess precipitation,
• 14,000 megalitres (millions of litres) entered the reservoir on 5th of December alone, and this could be argued to have prevented some of the flooding

Question 32

What were the Hard Engineering solutions attempted in Keswick?

Answer 32

• Therlmere resevoir
• Stone clad concrete flood wall in Penrith lane
• Glass panneled defence wall in High Hill
• Improving the flow of water through Botcherby Bridge

Question 33

What were the soft engineering solutions attempted in keswick?

Answer 33

-Floodplain zonation south of Keswick where land use is largely parkland and caravan sites

Question 34

How much was needed to restore roads and paths post 2015?

Answer 34

£7.9 million in restoration of roads and path