Uncategorized – Page 2

Broadwater Path one step away

SCHOOL DECISION DELAY

Fourteen years of effort by local residents and councillors have gone into getting agreement and funding for the Broadwater Path, along the edge of Broadwater Lake. As well as being a magnificent facility for the community, the path will help ensure the future of the lake itself. But there is an unexpected last minute obstacle.

Just as Surrey County Council was poised to complete formal dedication of Footpath 40 (Broadwater Path) in April 2016 and to begin work on laying the surface (with CIL funding agreed by Elmbridge BC), local residents were dismayed to learn that St George’s Weybridge had decided to oppose dedication of the path across its newly acquired land, despite a previous Deed of Planning Obligation.

So everything is on hold, except the continuing decline of the lake.

Broadwater Lake is progressively silting up and desperately in need of substantial dredging works and maintenance. Formalising public access to the lakeside will do more than simply give walkers a better path: it will open the way to public funding for maintaining this historically significant lake and exceptional local natural environment.

Strong local opinion

Local community groups have lobbied the school, seeking a change of mind. On 21 April 2016, PPDRA Chair Miles Macleod, presented a comprehensive case for permitting the dedication – you can download a copy of the PPDRA Broadwater Path Submission to School Governors here. You can also download the maps and plans. As you can read in the submission, the path may possibly be formalised with or without the school’s agreement, but school consent would greatly reduce the unexpected delay.

Subsequently the school has informally suggested a possibility of permitting a re-routed path. This would involve a diversion away from the lakeside before the school land, and along the paved lane from the health club.

In sounding this out, we have heard some strongly expressed views that the school should permit the original lakeside route. At our May PPDRA Committee meeting, after extended consideration of matter and of the school’s alternative route proposal, the view of the committee was strongly in favour of continuing to press for dedication of Broadwater Path along its original proposed route. We also agreed to continue seeking further views from the local community.

The path alongside Broadwater has been used informally and unopposed for as long as anyone can remember. Formalisation of the path alongside Broadwater Lake would bring benefits for the school as well as the community.

What are your views? Please do take a look at the facts set out in o ur submission.

Note: The picture on this page shows the new land purchased by the school in red, the Broadwater Path (proposed Footpath 40) in green, and Footpath 36 (which separates the old and new school land) in yellow.

Walton Lane Environment Agency flood meeting

Residents of Walton Lane, Weybridge, have gained new insights into the Thames Scheme flood plans by talking directly with people working for the Environment Agency on modelling river flows and levels.

A very informative meeting in Walton Lane on 25 April 2016 was attended by local residents, including PPDRA committee members Doug Myers and Miles Macleod. In the course of the meeting, at the request of local residents, it was agreed that flows of specific alternatives to widening Desborough Cut would also be modelled.

Headline learnings from the meeting include:

The 2014 floods were a ‘1 in 15 year’ event, based on historic evidence
Flooding has been unusually light in the Thames Valley for the past 40 years, so public expectations of flood risk are low compared with historic reality (and possible extreme events from climate change add more risk)
Flood Relief Channel 3 which discharges at Weybridge would carry its full design flow of 150 cumecs (cubic metres per second) at much lower total river flow volumes than reached in 2014 (which was 500 cumecs)
The flood relief channels would INCREASE the projected risk of Weybridge flooding unless something is done to increase flow downstream of Weybridge
The criterion of acceptability is that the works must NOT increase the predicted river levels for projected flood flows at any point (so downstream works are essential)
Widening the Desborough Cut on its south bank is considered to be the cheapest option to increase flow downstream (requiring driving in new vertical sheet piling to define the new bank and excavation of the current bank)
Widening on the northern bank of the Desborough Cut would be more expensive, as it has developed into a more natural kind of shelving bank with many trees limiting flow
Cost is a critical factor
Modelling predicts that Desborough Cut does not need to be widened much along its lower half: widening the upper half and dredging at the first bridge would increase flow sufficiently
Widening the bridges would be very expensive (and has not been budgeted for)
The 2014 floods scoured the river bed at the first Desborough bridge, significantly increasing the depth at that point
The Environment Agency are looking into potential alternatives to widening Desborough Channel (but the indications were not particularly positive)
Cutting ‘Doug’s Channel’ through Point Meadow (the north-west horn of Desborough Island) would also require widening or dredging of the remainder of the northern old river loop, which would be costly
The modelling team agreed to model the effect of this northern alternative approach on local levels and flows

Modelling of levels and flows is a highly complicated process, and not a precise science

1D modelling is relatively quick, but only considers the flow within the confines of the river
2D modelling includes flow in the adjacent flood plain, when levels are high, but is slow and very complex
Peer reviewing is a hands-on process, involving CH2M (formerly Halcrow) peer reviewing the JDA model and the design works, in “a process of questions and answers that get to an agreed design”
The overall margin of error in modelling appears to be higher than some of the predicted local changes in level which modelling suggests the scheme will produce, though the calculation of possible modelling error is far from straightforward
(Editor Comment: A truly robust approach would demand that the projected effects must be greater than the margin of error. However, logically the estimated margin of error of modelling can only be based on experience of disparity between modelled flows and actual measured flows.)

Future action timescale

Currently the River Thames Scheme has Treasury approval for the outline case (as previously reported)
Modelling with the latest data is in progress, 1D now, 2D in the coming months
A definitive outline design is planned by the end of 2016, following workshops
Scheme detailed design will follow that
Works timetable is for weirs work in 2018, relief channels in 2020

LATEST NEWS: UPDATE FROM ENVIRONMENT AGENCY 26 MAY 2016 SHOWS FUNDING SHORTFALL

Flood Update — River Thames Scheme interim answers

Following questions from PPDRA about the predicted effects of the proposed River Thames flood diversion channels — designed to discharge an additional 150 cubic metres of water per second back into the river at Weybridge — the Environment Agency River Thames Scheme team has helpfully provided some interim answers. See below.

These are reassuring in some respects, but show that the updated flow modelling, drawing on recent new evidence, has some way to go yet. We await further news.

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From: River Thames Scheme
Sent: 20 January 2016 17:08
To: ‘Miles Macleod’
Subject: Query regards modelling of tidal interface and thames barrier

Dear Mr Macleod

I apologise for my delayed reply.

Please see below our table of responses to your recent questions regarding modelling and tidal interface and Thames Barrier from our specialist teams.

Please be aware we are still awaiting the river modelling which we anticipate will be available in summer 2016.

Please do get in touch with us again if you have any further questions.

Yours sincerely

Felicitas Wappler
River Thames Scheme
Environment Agency Kings Meadow House, Kings Meadow Road, Reading, Berkshire RG1 8DQ

No.	Question	Answer
1	How would the progressive rise in level in the tidal Thames (upstream of the barrier) from river flow, over a high tide cycle (with/without the barrier closed) be changed by the increased maximum projected possible flow over an increased capacity Teddington Weir, as proposed under the RTS? (i.e. by how much would RTS increase the water level in the tidal Thames throughout the tide cycle, in a worst case scenario)	The hydraulic model that will be used to assess the impact of the RTS (including downstream of Teddington) is currently being finalised. The potential impact of the RTS will be tested with and without the Thames Barrier closed.
2	On what assumptions has that been calculated (worst case projected rainfall, worst case prior groundwater conditions, maximum flows upstream etc); how has it been modelled, and how has it been independently verified?	The hydraulic model of the lower Thames to test the RTS design is currently being finalised. The model extends from Hurley to Southend.Design flood conditions are represented in the model as inflow hydrographs for the Thames and its main tributaries, and a tidal water level boundary at Southend. The magnitudes of flows tested in the model are based on analysis of long-term flow records at gauging stations such as Windsor, Staines and Kingston. Therefore, the inflows to the model represent the effect of extreme rainfall and groundwater conditions, rather than modelling rainfall or groundwater directly. The model has been tested for a range of design flood magnitudes covering the following chances of occurring in any given year: 1 in 2 (50%); 1 in 5 (20%); 1 in 10 (10%); 1 in 20 (5%); 1 in 50 (2%); 1 in 75 (1.3%); 1 in 100 (1%); 1 in 200 (0.5%); and 1 in 1000 (0.1%). The downstream impact of the RTS is being assessed for each of these design events.The modelling work is being independently reviewed by CH2M. Their review covers the appropriateness of the model boundary conditions.
3	What is the current calculated effect of the RTS on levels in the Thames between Shepperton and Teddington, in worst case scenarios?	The hydraulic model that will be used to assess the impact of the RTS (including between Shepperton and Teddington) is currently being finalised.The objective of the downstream compensation measures (at the Desborough Cut and Sunbury, Molesey and Teddington weirs) is to reduce flood risk at all locations in this reach of the river with the RTS in place.
4	Is there a conceivable scenario in which the flows at Hampton / Molesey / Teddington weirs might be constrained to protect London from flooding, and what would the impact of that be on river levels between Shepperton and Teddington?	No, there is not a conceivable scenario where the lower Thames weir complexes would be operated to deliberately limit flows passing downstream to prevent flooding downstream of Teddington. With the RTS in place, the gates at Sunbury, Molesey and Teddington will continue to be operated in the same manner as they are currently. The gates at the weir complexes are progressively opened as river flows increase, so that in major floods all gates would be fully open.
5	Would it be correct to assume that the thinking (and conceivable maximum flows) may have moved on a little since the original work in framing the Lower Thames Flood Relief Strategy?	The magnitude of the design floods used in the modelling work have been reassessed as part of the update to the hydraulic model. This update makes use of the additional recorded flow data available in the last decade. This has resulted in changes to the peak flows to be used in the model, although these changes are relatively small.

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FURTHER UPDATE 10 February 2016

From: River Thames Scheme [mailto:rts@environment-agency.gov.uk]
Sent: 10 February 2016 09:16
To: ‘Miles Macleod’
Subject: FW: Query regards modelling of tidal interface and thames barrier

Dear Mr Macleod

Please find below the response from our specialist addressing your questions about peak flows and appropriateness of the model boundary conditions.

The peaks flows used in the modelling work are based on a statistical analysis of long-term records at flow gauging stations. The key station for the Lower Thames is Kingston, for which records are available since 1883 and is the longest continuous flow record available in the UK. The record has been extended up to the present day and this showed that including the Jan/Feb 2014 flood in the statistical analysis does not have a large impact on the peak flows used in the model compared to the estimates used previously in the Lower Thames Strategy. Partly this is because such a long flow record was already available. The second important factor is that the peak flow observed in February 2014 (500m3/s), whilst significant, is smaller than several other previous floods that will have been considered when deriving the Strategy peak flows. These floods include November 1894 (800m3/s), March 1947 (700m3/s), January 1915 (600m3/s), September 1968 (600m3/s), December 1929 (550m3/s) and November 1974 (550m3/s).

The 2014 flood was more exceptional in terms of its overall flood volume than its peak flow. That is, the flows remained very high for a longer duration than previous floods. The 2014 flood volume has been accounted for in the modelling work in the same way as peak flow, utilising statistical analyses of the long term flow records over a range of durations.

The scope of the CH2M review of the modelling work does cover the appropriateness of the flow peaks and flood volumes, and their assigned probabilities.

Please do contact us again if you require any further information.

Many thanks.

Kind regards

Felicitas Wappler
River Thames Scheme
Environment Agency
Kings Meadow House, Kings Meadow Road, Reading, Berkshire RG1 8DQ

Landmark Weybridge building at risk

A local landmark building in Church Walk, with a significant history as the first generating station for electric street lighting in England, is at risk.

Its fanlight windows with elegant arched brickwork on three aspects are key visual features in the local street scene, as are its traditional proportions, and its courtyard with an open view to the River Wey.

All these would be lost if the proposed new design as set out in planning application 2015/3135 were to be permitted– a two storey building with square windows, higher roof with large dormers, a blank gable end, and a huge single storey side extention and garage.

This historic street scene is too significant to lose.

Below is a photograph from 1989, when the original Weybridge Electric Light nameplate was still in place (photo courtesy of Di Balding).

UPDATE 3 October : Current application withdrawn. We await future proposals, which we hope willl be more sympathetic to the history and setting, given the number of strong and well argued objections lodged against 2015/3135.

Here is what PPDRA had to say about the application:

2015/3135 – Riverside Church Walk Weybridge Surrey KT13 8JT

This application proposes to change beyond recognition a landmark building in Weybridge, a building with a significant history as the generating station for the first electric street lighting.

We object to the proposed development on the following grounds:

1. Impact on Street Scene.

Visually this historic building is characterised by its fanlight windows with elegant arched brickwork on three aspects. Allowing the replacement of those features as proposed, with the visual mass of the additional height and dormer windows, would have a very negative impact on the street scene of this picturesque backwater.

The proposed single storey side extension and attached double garage would add considerable further visual mass (as would the proposed blank second floor wall on the north-eastern aspect, replacing what are currently attractive fanlights).

This would intrude strongly on the street scene in Church Walk, where currently the view approaching from the north is of the historic fanlights seen across a courtyard. It would intrude on the view from the east, especially as seen when approaching Church Walk along Beales Lane, from which the present the view is of courtyard and riverside trees beyond.

The proposed radical transformation of the aspect facing the River Wey would have a significantly damaging impact on the view from the Grade 2 Listed bridge over the Wey.

The removal of 5 metres of existing wall along the Church Walk footpath would expose the view of the proposed new bin area, directly in front of Portmore Cottages. We note that the front elevation shown in the application does not extend to this significant part of the proposal.

2. Impact on flood plain

The proposal design would more than double the footprint of a building in a Class 3 Flood Zone, which was threatened by flood as recently as last year.

3. Overdevelopment of riverside site

The proposal is to divide the current site of Riverside Studios 1 & 2 plus outbuilding Studio 3 in a new way, reducing the land attached to studios 2 & 3 (while leaving the portion of the site with the outbuilding Studio 3 undeveloped for now), and to more than double the footprint of the Studio 1 & 2 buildings in the truncated site to create two much larger dwellings. The impact on density would be dramatic and entirely unsuitable for this sensitive site.

4. Lack of parking provision

The proposal is to remove all onsite parking in the application site, and simply to offer a garage attached to one of the proposed dwellings. No parking space is proposed for the other dwelling. This is unacceptable for this non town centre site, given the severe lack of parking space in the privately owned stretch of Church Walk in front of Studios 1 & 2.

5. New vehicular access

The proposed removal of 5 metres of existing wall along the Church Walk footpath appears to be proposing vehicular access across what has always been solely a footpath (SCC FP18) at this point, relocating the access to Studios 1 & 2 and presumably allowing for future access to the Riverside Studio 3 site – whose current access would be obstructed by the proposed double garage – along and across FP18.

6. Amenity and safety of footpath users

The garage and bin access design do not appear to take into account the amenity and safety of users of the footpath (FP18).

Overall, the design proposed in 2015/3135 would have a significantly negative impact on an area which is prized for its charming street scene and history. Hence we urge refusal of this application.

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Historic note: Here is a piece on the history of the building, from the Parish Magazine, 1989

Excavated basements — good or bad?

A planning application for an excavated basement in Oakdale road, Weybridge, has raised some significant questions and divided views. Extending a house downwards has less impact on the street scene than a traditional extension, once completed. But the work of construction is a major undertaking that can disrupt local life for months.

London Boroughs have found unexpected problems during basement construction, resulting in prolonged projects, and substandard basements that leak and don’t live up to hopes. So they have tightened up on the requirements for granting consent, to ensure up front that the method of construction will be acceptable, in terms of impact during construction and the end result.

PPDRA feels that Elmbridge Borough Council should do the same. Here is the letter we wrote to the Head of Town Planning.