Calder Avenue culvert changes adding to Littleborough flooding?

The Mayor of Rochdale, Councillor Peter Evans, has added his weight to the concerns over flooding in Rochdale Borough. Mayor Evans has written to Donald Forrester of Rochdale Council asking why a builder had not been held responsible for changing a water course under Calder Avenue in Littleborough that has seen the peak flow rate entering a culvert increase from 5 to 50 thousand gallons of water per minute, and is adding to the effects of flooding in Littleborough and causing problems further downstream as the Roch passes through Rochdale.

The letter:

Donald,

Recent events have served to highlight the concerns that have arisen following the changes made to a water course by Wiggett Homes almost 9 years ago.

You may recall that prior to the removal of a lodge and the use of a field as a soakaway, the peak rate of flow entering a culvert behind Calder Avenue. Littleborough, was calculated by Andrew Kenny MSc (etc) a professional water engineer, to be about 5 thousand gallons per minute. Following the changes made by Wiggett Homes, the peak rate of flow at the same point has been increased to an estimated 50 thousand gallons per minute.

This change means that an extra one million gallons of water are passed through into Littleborough every 22-23 minutes during periods of heavy or prolonged rain, or during a thaw.

We saw that the River Roch broke its banks in Littleborough. Had the extra millions of gallons not added to the difficulties it is clear that the effects of flooding would not have been so severe in Littleborough and beyond.

I am also aware that under the flood defence scheme, provision was made to stop the flow of water into the River Roch in Littleborough at times of potential flood risk, however, since the culvert behind Calder Avenue collapsed into a lower culvert, it means that a 50 thousand gallons a minute flow is now split between two culverts - and only one of these is being addressed by officials currently. It is clear that a significant quantity of water has found its way into the River Roch regardless as to the efface of this position. This has obviously had a knock-on effect and has resulted in areas downstream, which obviously affects Rochdale town, suffering considerably more as a result.

A retired builder has telephoned me to express great concern that as a much larger flow now passes under the Calder Avenue estate it will, in his view, over a fairly short timescale, inevitably cause serious structural damage - the highest risks will be during winter months.

I am at a complete loss to understand why RMBC has not invoked the provisions of the Land Drainage Act 1991, which places an inviolable duty on a builder for the ramifications of changing a water course. Insurance against such a risk is compulsory. No one and no auhtority can mitigate that responsibility - so if it is alleged that someone from RMBC or United Utilities had expressed a view that it (the changes to a water course) was likely to be okay, (and I'm not suggesting that they did), it changes nothing, the 1991 Act ensures that the builder is held to account. Indeed, it is not possible under the 1991 Act for a builder to shift this burden of responsibility. For this reason, I question why RMBC have thus far, agreed to meet the costs, the estimates of which have varied dramatically from around £500,000 to £28,000 (the smaller figure being the current one).

I consider it totally unfair to levy the people of Rochdale Borough with any costs in this situation - but my principal fear is for the safety of people, buildings and property if the damaging impact of the significant change in water flow is not adequately addressed. Meanwhile, the likely cost of putting matters right is increasing disproportionately.

I respectfully ask that this matter be investigated as soon as possible please.

Regards,

Councillor Peter Evans
Littleborough Lakeside Ward