The bathing area, known as the Lido, is a rectangular area about 100 metres long and
30 metres wide on the southern bank of the Serpentine. The beach is a hard man-made
surface which has been fenced off for sunbathing, and gently slopes into the water.
Environment Agency monitoring has found occasional problems with faecal pollution
in this bathing water. One of the main sources of pollution to the Serpentine at
Hyde Park is suspected to be from animal faecal pollution, mainly birds. Since 2019,
the Environment Agency have investigated the Serpentine catchment in order to identify
possible sources of pollution. The Environment Agency and the Royal Parks are jointly
investigating the drainage system around the Serpentine, and reviewing bird and land
management in Hyde Park. The Environment Agency and its partners are working together
to investigate ways to improve the bathing water quality at the lido.
Modern sewerage systems have two separate systems, one takes foul sewage to sewage
treatment, the other takes rainwater runoff through surface water drains to rivers,
lakes and the sea. Misconnections occur when waste water pipes are plumbed into surface
water drains instead of the foul water sewerage system. This can give rise to pollution
when the waste water is discharged directly to the environment through the surface
water drain. For example, a washing machine or toilet may be incorrectly plumbed so
that it discharges to the surface drain rather than the foul sewage drain.
For the four year (2020-2023) assessment period where data is available, phytoplankton
(microscopic algae) was assessed as being sufficient to be objectionable for 8% of
visits, with 35% of visits noting the presence of phytoplankton (microscopic algae).
Phytoplankton (microscopic algae) increase in number at certain times of the year.
This process is known as a phytoplankton bloom. Blooms of phytoplankton, including
blue-green algae can result in the water appearing discoloured or a foam forming on
the water. If you observe a suspected bloom you are advised to not enter the water
and to contact your local authority health contact for help and advice.
There are no active pollution risk forecasts made at this bathing water. However any
bathing water has the potential to be affected by a pollution incident and if this
occurs a pollution risk warning with associated advice against bathing will be issued
on this website.
Environment Agency samplers make observations of litter present on the beach at every
visit, this includes assessments of sewage debris, litter and tar. At The Serpentine
- Hyde Park for the four year (2020-2023) assessment period where data is available,
sewage debris was not noted at this site. Litter was assessed as being sufficient
to be objectionable for 1% of visits, with 52% of visits noting the presence of litter.
Tarry residue was not noted at this site.
Seaweed (macroalgae) and phytoplankton (microscopic algae) are a natural part of the
marine and freshwater environment. Below we note whether these have been recorded
in quantities sufficient to be a nuisance.
The majority of sewers in England are “combined sewers” and carry both sewage and
surface water from roofs and drains. A storm overflow operates during heavy rainfall
when the sewerage system becomes overwhelmed by the amount of surface water. The overflow
prevents sewage from backing up pipes and flooding properties and gardens. An emergency
overflow will only operate infrequently, for example due to pump failure or blockage
in the sewerage system.
Heavy rain falling on pavements and roads often flows into surface water drains or
highway drains, ending up in local rivers and ultimately the sea. The quality of bathing
water may be adversely affected as a result of such events.
It is the Environment Agency role to drive improvement of water quality at bathing
waters that are at risk of failing higher standards. It is natural for water to run
off the land to the sea. Water quality at a bathing water is dependent upon the type
and area of land (the catchment) draining to the water and the activities undertaken
in that catchment.
