Memorandum by the Market Weighton Drainage
Board (IW 03)
INLAND WATERWAYSMARKET WEIGHTON CANAL
1.1 Market Weighton Drainage Board is one
of 247 Internal Drainage Boards (IDBs) situated in England and
Wales which administer potentially high flood risk lowland areas.
IDB's are statutory public bodies established under primary legislation
under which they have powers to undertake works, regulate activities,
and raise income within clearly defined drainage districts. People,
land and property within such districts have the potential to
derive benefit and protection from the service provided by IDBs.
The Market Weighton drainage district comprises some 20,000 Ha
(49,000 acres) of low lying land, with a wider catchment totalling
32,000 Ha (79,000 acres).
1.2 This district is served principally
by two main rivers, the River Foulness, and the Market Weighton
Canal, the latter of which is identified as an Inland Waterway
within the recent DETR publication Waterways for Tomorrow.
The Market Weighton Drainage Board is the navigation authority
for the Market Weighton Canal and as such is a member of the Association
of Inland Navigation Authorities (AINA). The Board is fully appreciative
of the proposals and objectives set out in the DETR publication,
however the Board feels that there are special circumstances attaching
to the operation of the Market Weighton Canal which require specific
recognition. These circumstances may quite possibly be unique
to this particular waterway.
2.1 Much of the drainage in this Board's
district came out of the 1772 Act of Parliament which gave powers
to the appointed Commissioners to construct a combined "Drainage
and Navigation" from the River Humber to the township of
Market Weighton. This became known as the Market Weighton Canal
from which the present Drainage Board derives its name being successor
in title to the original Trustees.
2.2 The Canal flourished as a commercial
navigation serving various brickworks situated along its route
until around 1850. With the advent of railways the Canal fell
into decline which gave rise to the later Act of 1900. Under this
Act the upper section of the Canal was closed, and the navigation
function effectively abandoned. The Canal then became solely a
primary drainage channel serving the wider catchment. Various
orders which have been made since have effectively closed the
remaining length of Canal to through navigation.
2.3 In 1951 the lower length of the Canal
was classified as main river which today comes under the control
of the Environment Agency. However, the Drainage Board still retains
the function of navigation authority although in practice this
function is administered by the Agency acting on the Board's behalf.
Water shedding from some 85 per cent of the Board's district drains
via the Market Weighton Canal prior to discharge into the Humber
Estuary through the Weighton Lock sluices. These sluices, which
are a listed structure, were completely refurbished by the Environment
Agency in 1994 at a cost of £1.5 million.
3. THE DRAINAGE
3.1 During the post war period the then
Yorkshire River Authority carried out considerable improvement
work along the main river length of the Canal and the River Foulness.
This involved widening and deepening the channel section, and
raising of flood defence embankments along parts of the length
protecting developed areas. In parallel with this the Drainage
Board undertook widespread improvement of the tributary drainage
system including the construction of six pumping stations. These
schemes were supported by MAFF and EEC funding.
3.2 In the present day the function of the
Market Weighton Canal as a primary drainage channel is more crucial
than ever before. The discharge arrangements from the Canal through
the lock sluices into the River Humber are subject to a tidal
range in the Estuary in excess of six metres. As tide levels continue
to rise the window of opportunity for discharging into the Humber
twice daily at low tide is being gradually reduced. At the same
time improved land drainage, continuing development, and more
extreme weather patterns result in more water being discharged
to main river in a much shorter period of time.
3.3 The combined affect of these two worsening
conditions is that more water has to be retained in main river
and tributary drains between tides. At times of peak flow this
can span several tidal cycles, and in Winter will very often result
in overtopping of river embankments causing flooding of undefended
low lying land situated alongside the river. The efficiency of
the gravity drainage system is seriously impaired throughout such
periods. The criticality of water level management in the Canal
(main river) is becoming ever more crucial year by year. It may
be noted that some 17,000 Ha (42,000 acres) of land is dependant
on the satisfactory management and control of the main river system.
4.1 It is recognised that the land drainage
function of the Market Weighton Canal may well be unique in its
own particular circumstances, although it may have similar comparisons
amongst a small number of other operating authorities. While not
wishing to distract attention from the main thrust of the DETR
proposals for waterways in general it is felt that this particular
waterway has a set of circumstances attaching to it which require
special recognition. It is the view of the Market Weighton Drainage
Board that with regard to the Market Weighton Canal the land drainage
function of this primary watercourse (waterway) must be given
priority over all other uses, and this is most strongly recommended.