SIR,

The material planning issues related to the Taylor Wimpey (TW) proposals for north west Vauxhall Fields must be quantified to develop a robust and credible evidence base on which the proposals can be judged (Monmouthshire County Council's Local Development Plan soundness test CE2).

The highest priority is undoubtedly the question of whether surface water management and drainage from the proposed development will exacerbate the incidents of flooding experienced in the Drybridge and Rockfield areas of Monmouth in recent years.

The approach TW promoted at the public meeting acknowledged the existing problems from the Rockfield estates but suggested the development on Vauxhall Fields would not add to these and may even alleviate them to some extent.

However, unless TW unequivocally demonstrates through a transparent and integrated approach that additional flooding will not be created or existing flooding perpetuated, there seems little point in considering their proposals as viable.

Such an approach must be risk-based, assessing the likelihood of certain events occurring and the consequences from these.

At least four specific events make important contributions to the potential for flooding in this part of Monmouth. These are;

a) the surface and drainage water generated from the proposed TW development by high intensity rainfall storm events, which will be directed towards the River Monnow;

b) the surface and drainage water generated from Rockfield and other parts of Monmouth by the same rainfall storm events;

c) the flows developed in the River Monnow as a result of the same rainfall storm events falling on Osbaston and other parts of the river catchment further upstream;

d) the restriction in the rate of water discharge down the Wye and Monnow rivers caused by high water from spring or near tides moving up the lower reaches of the River Wye.

If TW is going to clearly demonstrate the interactions and cumulative effects from these events it would be appropriate to develop a series of different scenarios based on combinations of the four events.

These will use standard data of rainfall intensity for different storm event return periods (eg one in 10 years, one in 50 years, one in 100 years or one in 500 years) and the duration of rainfall events (eg 12 hours and 24 hours).

TW should justify the return periods used and any assumptions it makes, such as the size of the areas draining towards Rockfield and Drybridge or the proportion of the Monnow catchment that will generate runoff into the river within the time scale of the selected rainfall events.

The occurrence of high water is predicted from tide tables and follow a two-week cycle.

The frequency with which the different combinations of the four events are expected to occur (ie the number of instances in a given period of time) using different storm event data can be calculated together with the extent of any predicted flooding.

If this information is shown on a series of maps, together with the areas currently affected by flooding, it will be relatively straightforward for local residents and their elected representatives to see what might happen.

They can then make an informed judgement on what is acceptable.

If the infrastructure problems can be resolved satisfactorily the remaining aesthetic and recreational elements (landscape, tree planting, allotments, footpaths etc) can be addressed alongside the great importance that people in Monmouth place on Vauxhall Fields as an area of significant natural value in the heart of Monmouth.

Geoff Ricks

(Monmouth)