Water pooled across Putney Embankment on Thursday afternoon as the first of two dramatic high tides triggered Environment Agency (EA) flood alerts along the riverside, signalling the start of autumn’s “high tide season” that will bring regular flooding risks through winter.
The tidal Thames reached 4.65 metres at Richmond Lock during the afternoon peak, prompting EA warnings for Putney Embankment, Chiswick Mall, Strand on the Green, and residential streets in Twickenham.
The EA issued a second flood alert for overnight Thursday into Friday morning, with the Thames forecast to reach 4.67 metres at Richmond Lock at 4:15am. The back-to-back alerts – affecting the same riverside areas within 12 hours – demonstrate the twice-daily tidal cycle that will characterise the coming months.
There are not expected to be any flooded properties but the towpath and riverside parking may well be inundated at peak tide. The alerts mark the beginning of a seasonal pattern that catches many riverside residents off guard.
The Thames experiences its highest tides during autumn and winter, with the coming weeks bringing several dates when flooding is likely.
Why Autumn brings higher tides
The pattern stems from the lunar cycle and the alignment of the sun, moon, and Earth. Every fortnight around new and full moons, the Thames experiences “spring tides” – nothing to do with the season, but named for the water “springing up” as gravitational forces combine to create higher tidal ranges.
These regular spring tides are amplified in autumn by two factors. First, we’ve just passed the September equinox, when the sun aligns with Earth’s equator, strengthening its gravitational effect. Second, several “super moons” this autumn – when the moon is closest to Earth in its orbit – will push tides even higher than normal.
Key dates to watch
Riverside residents should mark these dates when the highest tides are forecast:
November 5 – Super Full Moon (Beaver Moon). Expect very high tides for 2-3 days around this date.
November 20 – New Moon brings another round of spring tides.
December 4 – Another Super Full Moon. One of the highest tidal events of the year.
December 19 – New Moon spring tides close out the year’s highest tide season.
Between these peak events, “neap tides” occur when the sun and moon are at right angles to Earth, producing lower tidal ranges and minimal flood risk.
Which areas flood regularly
Local tide data from thamestides.org.uk reveals the Thames encroaches on Putney’s riverside areas more frequently than many residents realise.
Putney Embankment: Parking bays upstream from Putney Bridge flood on approximately 25% of high tides. The risk period typically runs between 2:00 and 6:00, both morning and evening.
Chiswick Mall: The river often covers the roadway at high tide, particularly near the junction with Chiswick Lane South by the brewery. During the highest tides, the road becomes impassable to many cars along its entire length from St Nicholas’ church to the Hammersmith boundary.
Strand on the Green: The riverside path floods during peak tides, though access to the three riverside pubs remains possible via Thames Road.
Twickenham: Thursday’s alert specifically named the towpath below Teddington Lock, Riverside and The Embankment areas.
How to prepare
Sign up for free flood warnings. Visit check-for-flooding.service.gov.uk and enter your postcode to receive alerts by phone, text, or email. You’ll be notified as soon as the EA issues warnings for your area.
Monitor tide predictions. The website thamestides.org.uk provides detailed predictions for Putney Bridge, Chiswick Mall, and other local spots, showing exactly when high tides will peak. The site explains that flooding becomes likely when tides reach 4.0 metres Above Ordnance Datum (mAOD) at Strand on the Green, with more extensive flooding expected above 4.3 mAOD.
Understand the pattern. Spring tides occur roughly every 14 days around new and full moons. Check a lunar calendar to anticipate when the next high tides are likely.
Avoid the water. The EA consistently warns against walking, cycling, or driving through flood water. Fast-flowing tidal water is deceptively dangerous.
Living with the Tidal Thames
The Thames has flooded Putney’s riverside paths and roads for centuries – it’s part of living beside a tidal river with one of the world’s highest tidal ranges. The river’s level can vary by over 7 metres between low and high tide at London Bridge.
The Port of London Authority notes that while tide predictions are generally accurate, actual conditions can be influenced by river flow and weather. Storm surges and strong winds can push tides significantly higher than predicted.
Thursday’s alert was updated throughout the day as the tide developed, with the EA confirming by evening that the high tide had passed without major incident. The system worked as designed – residents received advance warning, and vulnerable areas were identified before the water arrived.
With the November super moon less than two weeks away, Thursday and Friday’s back-to-back alerts are unlikely to be the last of the season. Residents can expect similar twice-daily warnings during each fortnight’s spring tide cycle.
