ALERTS are in force for four beaches across Bournemouth, Christchurch and Poole after storm sewage was discharged from a sewer overflow.

After heavy rain and thunderstorms on Saturday night, warnings are currently in place for Bournemouth Pier, Branksome Chine, Poole Park Lake and Poole Harbour Rockley Sands.

An interactive map on the Surfers Against Sewage (SAS) website is warning people of the water pollution alert.

Warnings are triggered when sewerage has entered the water within the last 48 hours.

The interactive map tracks real-time CSOs (combined sewage overflows) and PRFs (pollution risk forecasts).

The app monitors the water quality at over 400 locations around UK rivers and coastlines.

Bournemouth Pier

Pollution Alert: Storm sewage has been discharged from a sewer overflow in this location within the past 48 hours.

Forming part of the 15km stretch of Poole Bay, Bournemouth Pier is a sandy beach resort, about 1km wide, popular with a range of visitors located around Bournemouth Pier. A sewer overflow discharges 550m out to sea via a long sea outfall. The surrounding urban catchment may also affect bathing water quality.

Branksome Chine

Pollution Alert: Storm sewage has been discharged from a sewer overflow in this location within the past 48 hours.

Part of the 15km stretch of Poole Bay on the south coast, Branksome Chine is a long sandy beach resort backed by a promenade and cliffs. A sewer overflow discharges through a long sea outfall into the sea down the centre of the beach while other sewer overflows on the nearby Poole Harbour may also affect bathing water quality.

Poole Park Lake  

Pollution Alert: Storm sewage has been discharged from a sewer overflow in this location within the past 48 hours.

Poole Park Lake is located in an urban park adjacent to Poole Harbour. The boating lake is around 21 hectares in size and between 1 and 1.5 meters deep. The lake is filled via tidal sluice and local water drainage. Wessex Water provide data on their assets impacting this beach from the surrounding area.

Poole Harbour Rockley Sands

Pollution Risk Warning: Bathing not advised today due to the likelihood of reduced water quality.

Found well within Poole Harbour, Rockley Sands is a small sand and mud beach with a small harbour and slipway set below a train track and beside a large holiday park. It is very popular for watersports although swimming is limited. There are no sewer overflows discharging directly onto the beach, however, as the beach is located within Poole Harbour, the bathing water may be affected by other overflows from the surrounding area.