The Flood mitigation project carrried out over many years has now been concluded. By way of a final summary on the project please read the two letters below. The first from the Parish Council to the Environmental Agency and then the reply from the Environmental Agency

​Flooding Advice
If you or your neighbours are in immediate danger from flood water phone the Fire & Rescue Service on 999
In other circumstances : -
for sewer flooding - phone Southern Water on 0330 303 0368
for highway flooding - phone West Sussex CC on 01243 642105
for stream related flooding – phone Environment Agency on 0800 80 70 60
After the flooding incident has been dealt with, please leave a message with the Clerk to Loxwood Parish Council (either by email or telephone) for the incident to be investigated and added (in confidence) to our Loxwood Parish Council Flooding Database giving your name, address, date of incident and contact details. Please contact the Clerk by
 email               clerk@loxwood-pc.gov.uk 
 or telephone    01403 791323  (Office hours 9am to 11am Wednesdays; 9am to 1pm Thursday)

Flood Forum 19th October 10am Agenda

ZOOM Link
​Join Zoom Meeting
https://zoom.us/j/94948945551

Meeting ID: 949 4894 5551

The Parish Council has received a list of Preferred Options from the Consultant, Water Environment, for mitigation of flooding within Loxwood. The Parish Council will be meeting with Operation Watershed to discuss the financial feasibility in the next couple of months.

Water Environment will be re running the models produced to show the effect of flooding after heavy rainfall and the mitigation of flooding that various measures would achieve. They have written to the Environment Agency for rainfall data to further refine the modelling as well as intending to re model with a presumption of a clay substrate rather than as currently loam. This will all inevitably take time and a Meeting of the Parish Council, Water Environment and Operation Watershed to discuss possibilities for mitigation within the constraints of funding  will now not take place until the New Year.

Flood Forum meeting Minutes and presentation slides.
A further meeting between the Water Environment Consultancy, Operation Watershed and the Parish Council will take place to discuss priorities and funding for flood mitigation works. The minutes of this meeting will be published in due course. A date for the meeting has not yet been set as further work is required from Water Environment to establish a priority list.

Water Environment:
Model Development

1. The baseline (existing) model has been fully transferred into InfoWorks ICM, form the original strategy to undertake the work in HEC-RAS.
2. The model is run with an upstream flood hydrograph, and direct rainfall runoff on the modelled Loxwood catchment. The model should therefore be the best combination of a fluivial model (like the EA Flood Risk from Rivers mapping) and a pluvial model (like the EA Flood Risk form Surface Water).
3. The updated model is therefore able to replicate the overland surface water flooding of Burley Close.
4. The baseline model is still being improved to include the additional detail including headwalls, private garden walls and surfacing which may affect known property flooding.

 
Initial Assessment of Potential Options

1. Formal option modelling will only be undertaken once the baseline model is fully complete.
2. The model does show floodwater backing up upstream of the Guildford Road culvert, however opening up this culvert in isolation would likely increase flood water levels downstream at Pond Close and Oak Grove.
3. At Oak Grove, the model suggests that there the second twin culverted private crossing to no.6 Oak Grove (which was previously flooding) is an obstruction to flow, as water levels differ by 0.5m either sides of the culverts. One of the two pipe openings is half blocked, so and easy option would be to clear both culverts. The second option would be to remove the existing brick side walls and replace with railings. The replacement of the brick bridge side walls could also be done to the upstream twin culvert crossing to No. 5 Oak Grove. A further option could consider replacing both twin pipe culvert crossings with free span bridges or alternatively a larger box type opening.
4. Improving the drainage through Oak Grove unlikely to negatively impact houses downstream, with the exception of the properties at Burley Close.
5. The model will consider the benefit of opening up the culvert beneath Station Road, however a low flood defence barrier along the back of the properties at Burley Close may be necessary to reduce flood risk. The issue with a formal flood defence is that it may then also block surface water runoff from entering the river, creating additional flooding at Burley Close. The benefit of the latest update to the model is that this can be tested.
6. The model suggests that the source of the overland surface water flooding of Burley Close is from the uphill residential plots, rather than primarily from runoff from the school surfacing. Surface water seen coming through the school fencing, while including some contribution from the school surfacing, is from offsite runoff onto the school site. There may be some options which could be worked with the school to assist in better directing / converting overland flow to the river.