How far is the Grafham Water Trail Races?

The Grafham Water Trail Races offers 2 distances: Half Marathon (21.1 km / 13.1 miles), 10k (6.2 miles).

How much climbing is in the Grafham Water Trail Races?

The Half Marathon has 111 m of ascent. The 10k has 78 m of ascent.

How hard is the Grafham Water Trail Races?

Half Marathon: Hard. 10k: Moderate. Distances are measured off the course file. Where the file carries no elevation, the climb is the organiser's published figure.

Is the Grafham Water Trail Races course marked?

Yes, the course is marked. Navigation skills are not required.

What are the cut-offs for the Grafham Water Trail Races?

Overall time limits — Half Marathon: 4h, 10k: 4h.

Can I download the Grafham Water Trail Races route?

Yes. The GPX for each distance is free to download here, with no sign-up, the same as every route on Trail Running Planet.

When is the next Grafham Water Trail Races?

Sun, 11 Oct 2026, 09:00. Not open yet.

Race Harborough Grafham Water Trail Races

Marlow Park, Grafham Water, Grafham, HuntingdonSun, 11 Oct 2026

Marked 10k and half marathon trail races from Marlow Park, Grafham Water

Distance	Ascent	Per km
21.1 km Half Marathon	111 m	5 m
10k	78 m	8 m

reservoirMarked course

Nobody has reviewed this one yet

No reviews of the Grafham Water Trail Races, and nothing on what people wore. Both are things no organiser publishes and every runner wants before they enter — how it actually went, and what was on your feet.

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HARD

TRP grade · E3

4h cut-off, which needs 11:22/km

starts 09:00

Download GPXFree, no sign-up.

This file is from a previous running and the course may have changed since. If you are navigating with it, get the current version from Race Harborough first.

What you’re in for

Both races start and finish at Marlow Park on the shore of Grafham Water and head west towards Easton on farm tracks and stretches of the Three Shires Way bridleway. The 10k turns back onto the outward track, while the half marathon goes on to make a full lap of the reservoir, passing through a few small villages. The courses are arrowed and marshalled, with three water stations on the half and one on the 10k, but the races are cupless so bring your own. Dogs are not allowed because the routes cross farmland, in-ear headphones are banned, and parking at Marlow Park is pay and display.

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How to enter

Sun, 11 Oct 2026 · Not open yet · £25–£30

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Common questions

: The Grafham Water Trail Races offers 2 distances: Half Marathon (21.1 km / 13.1 miles), 10k (6.2 miles).
: The Half Marathon has 111 m of ascent. The 10k has 78 m of ascent.
: Half Marathon: Hard. 10k: Moderate. Distances are measured off the course file. Where the file carries no elevation, the climb is the organiser's published figure.
: Yes, the course is marked. Navigation skills are not required.
: We don't hold a compulsory kit list for the Grafham Water Trail Races. Race Harborough confirm mandatory kit in their race information, usually in the final instructions.
: Overall time limits — Half Marathon: 4h, 10k: 4h.
: We don't hold a checkpoint list for the Grafham Water Trail Races. What's on the table varies a lot between races, so check the Race Harborough race information rather than turning up expecting food.
: Yes. The GPX for each distance is free to download here, with no sign-up, the same as every route on Trail Running Planet.
: Sun, 11 Oct 2026, 09:00. Not open yet.