How is flow estimated?

EA CULHAM Downstream graph
EA CULHAM Upstream graph

from Environment Agency Guide 2012-2013

Right bank, tel: 01235 22061, length: 130'10", width: 17'6"

Culham Hydro

A privately funded 394KW hydro scheme with three Archimedes screws was opened in 2016 at Sutton Pools where the river braids into separate channels.

1801:  Surveyor recommended -

a cut to avoid the inconveniences at Sutton Poundlock, the only poundlock that does not belong to the commissioners.

[ The poundlock referred to was at the Mill and weir at Sutton Courteney. ]
1809:  The Culham poundlock opened.
1863:  The lock keeper was threatened with death by the miller at Sutton if he drew [opened] the weir

Culham Lock was in such a rotten state that two of the sluices out of four made no impression in emptying the water and the lock woman informed us that she did not know to whom to apply to repair it.

1884:  Culham Lock, Henry Taunt -

Culham Lock, Henry Taunt, 1884
Culham Lock, Henry Taunt, 1884
© Oxfordshire County Council Photographic Archive; HT3887

1886:  Armstrong

... the deepest, coldest lock on the Thames - this tomb-like lock

Culham Lock lantern slide 1883-1906, W.C.Hughes, research by Dr Wilson, courtesy of Pat Furley

1889: Jerome K Jerome -

From Clifton to Culham the river banks are flat, monotonous, and uninteresting, but, after you get through Culham Lock - the coldest and deepest lock on the river - the landscape improves.

1955: Culham Lock, Francis Frith

1955: Culham Lock, Francis Frith
1955: Culham Lock, Francis Frith

1957:  Lock House built.

Culham Lock full 1999 Culham Lock empty 1999
Culham Lock Full
Culham Lock Empty

[ Check your lines not everybody gets it right!
Looking at the above photos you get a feeling of the immense amount of water we use, going up and down locks - however - except in drought conditions - the weir will be passing far more water and our little contribution is not of importance.
In the online levels graphic above, the number of seconds of the total flow needed to fill the lock at the moment is shown. It will vary from a few seconds to several minutes or more.
In drought conditions it is sometimes important to understand the need to wait for locks to maximise the number of boats passed at one time. This is an issue of maintaining navigation and the quality of the river, rather than water supply
I think the above is only common sense - but if anyone knows better please correct me. ]

2007: And after all that talk of drought here is Culham Lock under other conditions!

Culham Lock in flood 2007
Culham Lock in flood, July 2007