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104
Environmental Health
London (Heathrow) Airport Noise Insulation Grants Scheme, 1966
That part of the "Defined Area" around London (Heathrow) Airport which is situated in the
Borough boundaries contains 1,960 Council houses and 6,000 private dwelling houses.
The Council have undertaken to carry out sound insulation in all its dwellings and approximately
400 are completed to British Airport Authority specification.
Of the 6,000 private dwelling houses 228 only have been completed but the increase in the grant
scheme has attracted more applicants in recent months.
FLOODING
Northern areas of Borough
The Borough suffered flooding in several areas, particularly during the severe weather conditions
of 14th, 15th and 16th September, 1968 when the local rainfall recorded was 1.45 inches of rain on
the 14th and 1.57 inches on the 15th.
The problem in the North Hillingdon area is caused by surface water getting into foul sewers,
partly through wrong connections and partly through infiltration of ground water into sewers near
rivers. Also flood waters enter foul drains via open gullies, and ill-fitting covers of manholes. In time
of heavy rainfall the whole foul sewage system becomes surcharged and overflows at certain low parts,
causing flooding with a diluted mixture of surface water and sewage.
North Hillingdon and Ickenham are drained to a common outfall sewer along Western Avenue
opposite Northolt Aerodrome and this outfall sewer is known to be inadequate.
The areas of North Hillingdon particularly affected by flooding were Lynhurst Crescent and
Long Lane opposite Park Way. Lynhurst Crescent is situated at the lowest part of the area, the
flooding taking place nearest to the Canal Feeder and the Yeading Brook. This flooding was caused
partly by the natural flow of surface water over the ground which is heavy clay, to the lowest point,
and partly by the overflow of the foul sewers.
The flooding at Long Lane is caused by overflowing of foul drains and sewers. A non-return
anti-flooding valve is fitted to the intercepting chamber serving the affected properties but this did
not appear to function properly in the case of this flooding and consideration is being given to fitting
some more positive form of valve, combined with a retaining chamber.
It is thought that the flooding in this area will persist until new and enlarged sewers are constructed.
Other parts of the Borough subject to persistent flooding in time of exceptional rainfall are
mainly in low lying areas, or at the foot of steep hills, as in Harefield Road at the junction of Gravel
Hill, Uxbridge and the Harefield Rubber Company's premises at the junction of Park Lane and
Summerhouse Lane, Harefield. In the case of the flooding at the Harefield Rubber Company, remedial
work has been carried out to divert the flow of storm water to a new line. Harefield Secondary School
had two classrooms flooded to a depth of two to three inches on 15/16th September and again on
17th December. During the heavy rainfall at the time, the foul sewer in Northwood Road became
surcharged and a mixture of storm water and sewage overflowed through the foul drain into the
school premises. The school is situated at the lowest part of Northwood Road and the ground slopes
down from the road towards the school, the floor level being more than two feet below road level.
Consequently, when the foul sewer becomes surcharged either from blockage or exceptional rainfall
the first point at which the sewage will overflow is in the school. In this case a non-return valve is to
be fitted to the school drainage connection and a storage tank provided to retain the sewage during
conditions of surcharge of the sewer.
Other instances of flooding occurred in similar circumstances in low lying property at Eastcote
Road, where gardens have been flooded with diluted sewage and surface water. Edwards Avenue,
South Ruislip, Park Avenue, Ruislip, Honey Hill, Uxbridge, Sharps Lane, Ruislip, North View,
Eastcote and Breakspear Road South, Ickenham, were also affected by flooding due to inadequate
surface water drainage.
Some flooding has also occurred in the Rickmansworth Road, The Avenue and Dene Road area
of Northwood and there is concern that re-development in Northwood, with blocks of flats or estates
of modern houses replacing under-occupied large mansions, may have the effect of overloading the
existing and sometimes inadequate soil and surface water sewers.