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Groundwater

Consultants are looking at the causes behind increases in groundwater levels around Kimpton

Kimpton Flood investigation (email)

Updated 23rd June 2014

The groundwater level has fallen at a rate of around 10cm a week or so since the last update.  The sump is now at 75cm.

Updated 18 May 2014

As a (hopefully) final update for this year, at least, the sump is currently sitting at 128cm, having receded steadily in recent weeks. Although the measurements are being taken regularly, by us, by the Environment Agency, and by North Hertfordshire District Council, we won’t update this page any further this year unless there is some exciting news to share!

Updated 20 March 2014

The water level in the sump continues to rise, but at a much slower rate, and the risk of flooding seems to be increasingly remote, which is good news.  Having said that, we cannot be complacent and will continue to keep a close eye on the situation. Today’s measurement is 161cm.

Updated 11 March 2014

We have received another briefing note from the Environment Agency, pointing out that the levels of groundwater being measured are broadly the same as at this time last year, and the situation is still being monitored.  The risk of groundwater flooding in Kimpton is described as ‘moderate’.

The document can be read in full here.

Updated 10 March 2014

The levels seem to be easing back slightly – the sump is now at 144cm, so has risen well below the mean of 6cm daily noted on 4 March.  We are not complacent, however, and will keep measuring and reporting.

Updated 04 March 2014

After 22 days of monitoring, the sump is now sitting at 131cm.  This represents a mean rise of nearly 6cm daily, although the actual amounts vary widely – some days it is a single centimetre or so, and more on other days.  We are now just under 1 metre from the point at which flooding becomes a risk, and that represents around 16 to 17 days if the current mean rise is maintained.

Of course, there is no indication that a flood will definitely occur, so this data is provided as an indicator only.

We have also simplified the graph, to make display easier – the first few readings are at weekly intervals and then daily thereafter.  if you want the daily numbers, then they are listed in a table at the bottom of this post, below the graph.

Updated 25 February 2014:

We have received a briefing note from the Environment Agency, via North Hertfordshire District Council.  The document can be viewed here.

Updated 23 February 2014:

The level is now 98cm …

Updated 21 February 2014:

We now have accurate measuring facilities and keys to the sump, so will be monitoring the levels ourselves with a greater degree of accuracy!

Updated 18 February 2014:

North Hertfordshire District Council have notified us that the measurement is now 70cm, up from 62 yesterday. Flood risk is at 230cm, so they are working on the assumption that if flooding occurs it may be in 20 days at the current rate of groundwater rise.

Original post 17 February 2014:

As you will be well aware, there has been a good deal of rain in recent months, and we have been monitoring the levels of groundwater in the sump on Claggy Road.

Until very recently this was dry, because despite the rainfall, it takes some weeks for the groundwater levels to begin to rise as the water seeps through.

We have now noted some water, and the chart below shows the progression since the first appearance on 11th February. The initial bar on the chart indicates the 2 meter limit, after which we need to anticipate that some flooding may occur.

It’s important not to be complacent about the risk – there is no degree of certainty that a flood will occur – we had significant levels a year or so ago, and there was no flood – but it is important to be prepared.

As you can see, a consistent rise in the levels in the sump could bring it to the 2 meter level in about three weeks’ time. As a result of this, the Parish Council is talking with Hertfordshire County Council about the provision of a similar pipe to that used in the 2001 flood, where water was diverted into a specially created chamber in Park Lane, and then into the drainage system. For those that don’t remember that incident, the pipe ran along the footpath between Claggy Road and Park Lane. It remains to be seen whether we will get a response, but please keep visiting this page to stay up to date with where the water levels are currently. You will then have as much information as we have!

Date Water level (cms)
TOP OF SUMP 230
11/02 9
12/02 20
13/02 30
14/02 41
15/02 48
16/02 56
17/02 62
18/02 70
19/02 73
20/02 84
21/02 89
22/02 94
23/02 98
24/02 100
25/02 107
26/02 108
27/02 112
28/02 118
01/03 120
02/03 126
03/03 128
04/03 131
05/03  134
06/03  135
07/03  137
08/03  139
09/03  141
10/03 144
11/03 145
12/03 146
13/03 148
14/03 150
15/03 152
16/03 154
17/03 156
18/03 158
19/03 159
20/03 161