The flood risks with building the 1,400 homes in North Witney have not been resolved. It has been suggested that the proposed West End Link Road bridge which joins at the Cannon Pool junction of Hailey Road and West End, would also serve as a flood defence dam for central Witney. The reality is, however, that it makes little to no difference to central Witney but increases the risk of flooding for some homes upstream of the bridge on Crawley Road.

 

Importantly, the issue of flooding in Eastfield Road and Hailey Road from the Hailey Drain has not been resolved. Local residents will not need reminding of the devastating effects of flooding in 2007.

 

You can read more about our detailed findings below.

 

FAILING to protect Witney centre from flooding from the River Windrush ..... by using the West End Link Road as a ‘dam’, and alleviating floodwater entering Hailey Road from the Hailey Road Drain flowing through North Witney SDA)

 

Evidence

 

Report ENV4 – Witney Level 2 Strategic Flood Risk Assessment 2015

https://www.westoxon.gov.uk/media/1236409/ENV-4-Witney-Level-2-Strategic-Flood-Risk-Assessment-March-2015-.pdf

 

 

(Page 50)

Table 4 – Summary of Flood Impact due to Option 1

 

Location Impact Assessment

 

Upstream of WEL - No significant change in flood depths, all impacts are less than 10mm.

 

At WEL - No significant change in flood depths, all impacts are less than 10mm.

 

Downstream of WEL - No significant change in flood depths, all impacts are less than 10mm.

 

(Page 51)

Table 5 - Summary of Flood Impact due to Option 2

 

Location Impact Assessment

 

Upstream of WEL - No significant change in flood depths, all impacts are less than 10mm.

 

At WEL - Upstream face of WEL - Some back water affect causing an increased flood depth on the upstream face of the embankment for the WEL.

- Increased flood depths extend approximately 75m upstream.

- Increases in flood depth in the range of 10mm to 25mm.

 

Downstream face of WEL - Some decreases in flood depth on the downstream face of the embankment for the WEL.

- Decreased flood depths extend up to 25m downstream.

- Decreases in flood depth in the range of -10mm to -15mm. (1/2 an inch)

 

Downstream of WEL - No significant change in flood depths, all impacts are less than 10mm.

 

(Page 52)

Table 6 - Summary of Flood Impact due to Option 3

 

Location Impact Assessment

 

Upstream of WEL - Significant increases in flood depths.

 - Impact on flood depths extend approximately 550m upstream of WEL.

- Flood depths increased in the range of 100mm to 300mm.

 

 At WEL - Upstream face of WEL - Significant increases in flood depths.

- Flood depths increased in the range of 300mm to 325mm.

 

 Downstream face of WEL - Some decreases in flood depth on the downstream face of the embankment for the WEL.

- Decreased flood depths extend up to 90m downstream.

- Decreases in flood depth in the range of -25mm to -65mm.

- Immediately after the restricted flow area, increased turbulence within the channel causes increased flood depths in the range of 20mm to 50mm

 

- Downstream of WEL - No significant change in flood depths, all impacts are less than 10mm.

 

 

 

Report WOLP35 – River Windrush Flood Analysis, Delivery Report 2015

https://www.westoxon.gov.uk/media/1304289/WOLP35-River-Windrush-Flood-Analysis-Delivery-Report-Jacksons-March-2015.pdf

 

Page 35

  1. CONCLUSIONS

 

7.1 This modelling assessment has determined that there is negligible impact on flood levels during the climate change 1 in 100 year event as a result of a proposed bridge crossing over the River Windrush and its floodplain.

 

7.2 This assessment has investigated the possibility of alleviating properties of flooding downstream of the proposed bridge location by reducing the proposed bridge openings.  The results have shown that there is negligible impact on water levels downstream of the proposed bridge during the climate change 1 in 100 year event, however, water levels upstream of the proposed bridge increase significantly which, in turn, results in an increased flood risk to properties along Crawley Road.

 

7.3 Therefore, it is recommended that Bridge Scenario B is not pursued further. 

7.4 When considering Scenario A, despite three openings being modelled, it is considered that the original scheme as provided by the Client and shown on Drawing Number 43163-S-11, (which includes additional openings), would have even less of an impact on water levels in comparison to the baseline model results and Bridge Scenario A. 

 

The above two reports appear to contradict this statement in WODC’s adopted Local Plan.

https://www.westoxon.gov.uk/media/1936509/Local-Plan-BOOK-WEB.pdf

 

9.2.44 Importantly, the West End Link could offer the potential to serve a ‘dual’ role not only in terms of transport but also in terms of flood risk mitigation – the concept of which has the support of Oxfordshire County Council and the Environment Agency. Any development proposal will need to be supported by a detailed Flood Risk Assessment (FRA).   

 

 

NWAG Conclusion

 

Despite the WODC statement above, the conclusion of NWAG is that the proposed West End Link Road (bridge) cannot be engineered to reduce the flood risk in Witney from the River Windrush, and therefore cannot serve a ‘dual’ role.

It can only be used as a transport link built directly on the River Windrush ZONE 3b floodplain, and costing £23m (2015).

 

 

Failing to reduce floodwater entering Eastfield Road and Hailey Road from the Hailey Road Drain

 

It is also our opinion that, Local Plan POLICY WIT2 (North Witney Strategic Development Area), Paragraph - (m) and flood alleviation measures to reduce flood risk associated with the Hailey Road Drain should be incorporated where appropriate.

 

This is a weak Policy statement and is in danger of being breached as a requirement of building 1,400 houses in north Witney.    (appropriate is defined as suitable or proper in the circumstances).

 

This is a video of the Hailey Road Drain in flood and its devastating effects on both Eastfield Road and Hailey Road.

 

 URL: https://youtu.be/TjzAzl4GXw8

 

 

NWAG Conclusion

Witney and its residents are likely to be little or no better off from local flooding issues, and WODC will have failed in their duty to alleviate this situation should this conclusion prove to be correct.