The bridge at Crowthers Nursery crosses the River Roding which is running parallel to Ongar Road at this point.
Abridge: Grid Reference: 467 968
The bridge at Abridge Runs past the town centre and passes over the River Roding on Abridge Road.
Debden: Grid Reference: 443 956
The bridge at Debden Crosses the River Roding on Chigwell Lane near Debden Station and adjacent to the M11 Motorway and Debden Sports Club.
Buckhurst Hill: Grid Reference: 423 932
The bridge at Buckhurst Hill crosses the river Roding between Roding Valley Station and Chigwell Station. It runs next to some recreation ground and a public footpath.
Redbridge: Grid Reference: 387 972
The bridge at Redbridge is adjacent to the M11 Motorway and is next to Redbridge roundabout. It is also opposite some recreation ground as in Eton Manor Rugby Club. The River Roding runs along the M11 and also next to a public footpath there.
Data Collection: On the trip to the River Roding to investigate the flooding threat, our primary data consisted of two types – Observational and measurements.
Primary Data: Our primary data is the results we collected on the actual day of our Trip to the River Roding.
At each of the sites we investigated, we observed the land use, the evidence of flooding and what flood control was in place at each site. We would write down what the land around that section was being used for, for example-arable farming. We also observed to see if there was any evidence of flooding, we could do this by looking at the bridges, and seeing if there was a tide mark where water had previously been, we could also see if there was any debris on the banks of the river which may have been washed up by previous floods. Our last observation would be to see if there were any measures of flood control, for example concrete banks, spillways and weirs.
A field sketch would be drawn at each site to record what the site and bridge looked like, so later on in the investigation we could make references to these field sketches. All the field sketches drawn at each site were annotated and labelled to show detail. We also took photos at each site which we could also refer to later on in the investigation. Also these photos could be compared t previous photos or later photos to see the difference in the height of the river at different times. These photos were also annotated and labelled.
At each site we would record measurements for different things such as velocity of river, infiltration and depth of river which would be able to calculate the cross-section of the river.
Measurable techniques:
- For measuring velocity, we would measure 10 metres downstream and put a dog biscuit in the water at 0 meters. We then timed how long the dog biscuit took to travel 10 metres. We recorded our results then converted them into metres per second (m/s). This would show us the speed of the river downstream. We encountered some problems measuring the velocity because it was difficult to put the dog biscuit in the river at exactly 0m ad to stop the watch at exactly 10m. So if we had a measuring tape to put in the water we could have measure velocity more accurately.
- For measuring infiltration we placed a cylindrical flask with no top or bottom which measured up to 100 mm. We stuck the flask into the ground directly next to the river bank so that 0mm was just at the level of the ground. We then filled the flask with water to 100 mm and then timed how long it took for the water to be absorbed into the ground. We recorded the results then converted them in to millimetres per minute (mm/min). We repeated this 3 metres away from the river bank. This would show us the permeability of the ground next to the river. We encountered some problems while measuring the infiltration, such as it was hard to read the measurements on the flask and it was hard to tell whether the flask was touching 0mm. So a more accurate cylindrical flask would have helped.
- For calculating the river cross-section we measured the depth to water and depth to river bed/bank from the bridge. We used string attached to a weight and lowered it from the bridge to the waters surface, then measured that distance on the string with a measuring tape. We then lowered the weight until it touched the river bed or river bank and measured that distance. We did these measurements at certain intervals along the bridge e.g. 0m, 3m, 5m, 7m and 11m. These measurements allowed us to calculate and draw a cross-section of the river. This would show how the shape of the river changes as you move further downstream and show us the height to flood. We encountered some problems measuring the cross-section such as losing grip on the rope and not seeing where we measured to, and also with debris in the river, we could not always touch the river bed with the weight.
Visual techniques
- For observing the land use, I looked around the site and saw whether it was agricultural land for example, or arable, residential or recreational. This enables us to see what damage would be done if the flood plain was to flood.
- For observing Evidence of flooding, I looked for tide marks on bridges or debris left on the river bank from previous floods. This would let us see how many floods, and how high previous floods have been.
- For observing evidence of management, I looked for obvious things like spillways and weirs, then I looked for things like concrete mattresses and banks. I also looked to see how high residential areas or roads were compared to the river, this would determine whether there was soft management. This enabled us to assess whether the council is doing enough with flood defence and to see if they are working adequately.
Here is a photo of the measurement of infiltration.
I also collected data by conducting a survey using a questionnaire; I asked 10 people these questions. Below is the questionnaire.
Questionnaire
Sex:
Age:
What town do u live in?
Do you live in any flood areas of the River Roding?
How long have you lived near the River Roding?
Have u been affected by The River Roding’s previous floods?
Do you think the council have done enough to prevent further flooding?
Do you feel safe living near the River Roding?
Would you consider moving away from the River Roding if you could?
Data Collection Form – River Roding October 2005
Site: Grid Reference:
Field Sketch:
Land Use:
Evidence of Flooding:
Evidence Of management:
Height to Flood:
Cross Section:
Infiltration:
Velocity:
Secondary Data: Here is some secondary date I collected from leaflets and websites.
Thames Region Information
Welcome to the Thames Region of the Environment Agency.
The Region covers the Thames basin - the area surrounding the River Thames where rain falls and runs into the river. The Thames flows for 205 miles from Thames Head Bridge in the Cotswold’s to its confluence with the North Sea at Shoeburyness in Essex. On its course the Thames passes through picturesque villages, the large towns of Oxford, Reading and Maidenhead and the historic centres of Windsor and Henley.
More than 12 million people live in Thames Region and the number is rising. This means there is a lot of pressure to provide houses and drinking water, and to get rid of our rubbish properly and safely. How might we recycle more rubbish, or have less waste in the first place? How can we make our air and river water clean enough for people to enjoy their surroundings and for wildlife to survive? How could we stop rivers from flooding homes and businesses?
We need to think about all these problems and work with other organisations to solve them.
Thames Region Facts and Figures
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The Thames Region is responsible for the protection of an area 13,000 km2, covering the River Thames and its tributaries.
- There are 5,330km of main river in the region.
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The area of floodplain is 896 km2.
- The region is amongst the driest in the UK. It receives an average of 690mm rainfall per year compared with an annual national average of 897mm.
- The region has less than 10% of the land area of England and Wales, but nearly a quarter of the population and generates more that a quarter of the Gross National Product
- The Thames path follows the river for 184 miles from its source, through rich and contrasting countryside before entering London where it ends just a few miles from the sea.
- The source of the Thames lies in a remote Gloucestershire meadow.
- The non-tidal Thames is 147 miles long passing through 44 picturesque locks.
- The Thames is home to important wildlife habitats and there are 146 sites of special scientific interest within five kms from the banks.
- The Tidal Thames is now cleaner and healthier than it has been for nearly 200 years and supports a wide variety of wildlife. This thriving habitat supports 119 different species of fish.
Thames Region has:
- Effluent discharge consents - 9018
- Major industrial processes - 135
- Sites using radioactive materials - 274
- Nuclear sites - 7
- Waste management Sites - 845
- Licensed waste carriers or brokers - 13093
- Sites of special scientific interest – 462
Roding Valley Meadows LNR, Chigwell.
Situated on the flood plain of the River Roding, this large site is a haven for wildlife. With orchids in summer, limousin cattle graze the lush pastures which helps maintain the meadow’s amazing flora. 56.5 Hectares. The site has a network of hardened pathways.
Grid Reference TQ 430 942. Car Park off Roding Lane, Chigwell.
Below are some articles concerning floods and flood defence around the River Roding.
£125,000 to prevent floods
FLOOD-risk management could be funded to the tune of £75,000 over the next three years to prevent a re-occurrence of the River Roding flood of 2000.
More than 250 residential and commercial properties were deluged by the floods in October of that year leaving homes uninhabitable for up to nine months.
Under budget proposals currently being considered by the council the money would be used to carry out surveys to assess drainage issues in the area. That information would then be used to decide what works were necessary to cut the risk of flooding.
A report for councilors read: "The Environment Agency has committed major funds to the flood investigation and is treating it as a high priority.
"Thames Water and Redbridge have agreed that they should work in partnership with the Environment Agency and assist with sharing information and funding related parts of the investigation."
The council has also penciled in £50,000 over the next two years to tackle poor highway drainage at the junction of Whitehall Road and the High Road, Woodford Wells.
Fire station pumping crews have often had to attend floods at the site in the last three years and a council report warns that without the work the road and surrounding buildings risk long-term damage.
Drainage problems were blamed for flooding in Chigwell Road in 2000. Residents of Wanstead Park Road and Roding Lane South were also affected with several having to spend a night at a rest centre set up at Caterham High School.
The report says: "Failure to address the causes of flooding and undertaking remedial works will result in increased occurrences of the Redbridge Major Incident Plan (REDMIP) and costs associated with flood management and damage as well as increased complaints and concerns from residents in the areas affected."
8:45pm Wednesday 21st January 2004
Residents find river flood protection disappointing
By
FIVE years after the flood that devastated hundreds of houses in Woodford Green, the Environment Agency presented its plans to protect residents from the River Roding.
A drop-in session at Broadmead Church in Chigwell Road, which was flooded by the deluge in 2000, saw visitors presented with 11 options for dealing with the river but without any suggestion as to the degree of protection that would be offered by each, or what each would cost.
The presentation met a disappointed response from residents and councilors annoyed that they had been denied the opportunity of a formal public meeting. Bridge ward councilor Morris Hickey said: "They had the temerity to refer to the exercise as a consultation. It's taken five years for them to produce this; well, the gestation period of an elephant is only two years and at least they produce something at the end of it.
"It was all very cleverly done. In previous meetings the EA was under constant fire from all directions but often the vociferous few articulate the thoughts of the silent majority." The EA emphasises that the risk of flooding cannot be eliminated but that it plans to reduce the annual likelihood of properties being flooded from one in 50 to one in 100.
Margaret Smith of Glastonbury Avenue said: "It was very pleasant when we were there but when we came away I thought, what have we achieved? My feeling was, nothing. I can't see how telling us what we already know does us any good."
Feedback from the meeting will be taken into account when the EA publishes its much-delayed flood risk management strategy, currently due at the end of 2006. Cllr Hickey said: "It told us very little that we didn't already know and I'm angry about the waste of time and the waste of money. Residents should make their views known to the EA as if there is no tomorrow."
Agency spokeswoman Emma Cassidy said they had received a lot of positive feedback from the meeting and emphasised that the river studies took time. She said: "We understand people's frustrations, but we have to look at the River Roding from start to finish, and that does take some time.
"It's a hard message to tell people, but we're doing all we can and we feel we are in a good position to get the ball rolling.
"The studies are all nearly finished."
3:00pm Saturday 24th September 2005
