Rainfall

 

The flow in the River Ver is dependent on rainfall to recharge the aquifer, from which water is pumped to supply the needs of the district (see Aquifer page).  Recharge largely happens in the winter and early spring; any rainfall during the summer has little effect as surface water evaporates and is used up by growing vegetation. Although after heavy rains, at any time of year, the run-off can cause short-term improvement in flow, it takes many weeks for any effect to be measured in aquifer levels or to have any long-term effect on the river.

 It is therefore important for the Ver Valley Society to monitor rainfall figures regularly throughout the year and we do this with the help of Rothampstead Research Station (see tables below). 2008 was the wettest year since 2000. In 2009 rainfall was nearly 10% above average and as the Bow Bridge Pumping Station (see aquifer notes) was shut down until August good flows were recorded in the first half of that year and the aquifer came back to average values. Subsequent rainfall in 2009 and 2010 generally fell below average but flows remained moderate. However poor winter rains and most of 2011 mean the river was exceptionally low by the end of 2011.

See rainfall figures below.

 


 

Rainfall 2011

 

Month 2011 Actual rainfall (2010) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 84.6 70.0 14.6 120.9%
February 56.8 50.1 6.7 113.3%
March 10.0 50.8 -40.8 19.7%
April 5.2 55.1 -49.9 9.4%
May 23.6 54.7 -31.1 43.2%
June 83.0 53.3 29.7 155.8%
July 44.6 49.9 -5.3 89.4%
August 81.2 63.7 17.5 127.4%
September 38.4 57.6 -19.2 66.6%
October 25.2 81.7 -56.5 30.9%
November 36.4 76.6 -40.2 47.5%
December 82.4 69.5 12.9 118.5%
         
TOTALS 571.4 732.9 -161.5 78.0%

 

Rainfall 2010

 

Month 2010 Actual rainfall (2010) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 47.3 69.7 -22.4 67.9%
February 77.2 48.8 28.4 158.2%
March 45.2 53.9 -8.7 83.8%
April 18.7 53.4 -34.7 35.0%
May 38.4 49.7 -11.3 77.3%
June 23.5 60.2 -36.7 39.0%
July 31.6 42.1 -10.5 75.1%
August 127.6 53.5 74.1 238.3%
September

59.7

61.0

-1.3

97.9%
October 84.9 74.7 10.2 113.7%
November 54.9 66.3 -11.4 82.8%
December 35.3 70.1 -34.8 50.4%
     
TOTALS 644.3 703.4 -59.1 91.6%

 

Rainfall 2009

 

Month 2009 Actual rainfall (2009) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 70.4 69.7 0.7 101.0%
February 73.9 48.8 25.1 151.4%
March 37.3 53.9 -16.6 69.2%
April 46.7 53.5 -6.8 87.3%
May 24.8 49.7 -24.9 49.9%
June 68.1 60.2 7.9 113.1%
July 73.3 42.1 31.2 174.1%
August 63.4 53.7 9.7 118.1%
September 15.9 61.0 -45.1 26.1%
October 39.1 74.7 -35.6 52.4%
November 146.1 66.2 79.9 220.6%
December 105.2 70.1 35.1 150.0%
   
TOTALS 764.2 703.6 60.6 108.6%

 

Rainfall 2008

 

Month 2008 Actual rainfall (2008) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 103.20 69.70 33.50 148.1%
February 21.90 48.80 -26.90 44.9%
March 108.50 53.90 54.60 201.3%
April 53.50 53.50 0.00 100.0%
May 87.00 49.70 37.30 175.1%
June 35.30 60.20 -24.90 58.6%
July 90.3 42.00 48.30 215.0%
August 107.8 53.70 54.10 200.7%
September 66.2 61.00 5.20 108.5%
October 74.3 74.7 -0.40 99.5%
November 91.1 66.2 24.90 137.6%
December 42.0 70.1 -28.10 59.9%
   
TOTALS 881.10 703.50 177.60 125.2%

 

Rainfall 2007

 

Month 2007 Actual rainfall (2007) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 91.60 69.70 21.90 131.4%
February 97.44 48.60 48.84 200.5%
March 57.60 53.90 3.70 106.9%
April 2.80 53.50 -50.70 5.2%
May 135.80 49.70 86.10 273.2%
June 72.40 60.20 12.20 120.3%
July 86.8 44.60 42.20 194.6%
August 64.6 53.90 10.70 119.9%
September 29.2 61.00 -31.80 47.9%
October 57.1 74.7 -17.60 76.4%
November 80.0 66.2 13.80 120.8%
December 67.1 70.1 -3.00 95.7%
   
TOTALS 842.44 706.10 136.34 119.3%

 

Rainfall 2006

 

Month 2006 Actual Rainfall (2006) Millimetres Average Rainfall Millimetres +/- mm Average Percent Average
January 29.20 69.70 -40.50 41.9%
February 41.40 48.80 -7.40 84.8%
March 49.50 53.90 -4.40 91.8%
April 51.00 53.50 -2.50 95.3%
May 89.00 49.70 39.30 179.1%
June 15.00 60.20 -45.20 24.9%
July 35.60 42.10 -6.50 84.6%
August 110.00 53.70 56.30 204.8%
September 54.20 61.00 -6.80 88.9%
October 105.00 74.70 30.30 140.6%
November 104.40 66.20 38.20 157.7%
December 95.00 74.10 20.90 128.2%
         
TOTALS 779.30 707.60 71.70 110.1%

 

Rainfall 2005

 

Month 2005 Actual rainfall (2005) Millimetres Average Rainfall in Millimetres +/- mm Average Percent Average
January 33.8 69.7 -35.9 48.5%
February 36.2 48.8 -12.6 74.2%
March 43.2 53.4 -10.2 80.9%
April 65.6 53.5 12.1 122.6%
May 44.4 49.7 -5.3 89.3%
June 44.0 60.2 -16.2 73.1%
July 39.0 42.1 -3.1 92.6%
August 58.6 53.7 4.9 109.1%
September 65.0 61.0 4.0 106.6%
October 88.4 74.7 13.7 118.3%
November 53.8 66.8 -13.0 80.5%
December 53.0 74.5 -21.5 71.1%
         
TOTALS 625.0 708.1 -83.1 88.3%

.. © River Ver 2011