Thursday's meeting at Wincanton has been abandoned due to a waterlogged track.
Clerk of the course Barry Johnson initially called an inspection for raceday morning after substantial overnight rain.
However, he brought that check forward to 12.30pm following further rain, before eventually calling the meeting off around 12 noon.
Johnson said: "We've had 34mm of rain since one o'clock and it's still raining.
"I have never seen it so wet. There is more rain forecast for Thursday and we have no chance of recovering in time for racing."
Officials at Hereford have also been forced to abandon their National Hunt fixture.
Clerk of the course Keith Ottesen announced a lunchtime inspection earlier this morning following persistent rain, and to make matters worse a culvert (a type of drain) that runs through the centre of the course has burst.
Ottesen said: "It's been getting worse and we're up to 27 millimetres of rain now. We weren't expecting anywhere near that amount."
He added: "Up to 7am we'd had 14mm but as it carried on raining all of the water from the surrounding areas and the water courses are culverted and can't cope with it all.
"We are flooded in parts because those water courses that take the water around the racecourse and underneath it have been breached. The ground everywhere is saturated and cannot take this amount of rain in such a short space of time."
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