There are several water taps. Below is link to 'My Google map' of SDW with overall locations of water taps. (Please note that SDW route is approx due to detail of map)
Winchester to Devils Dyke
ditto but whole of SDW to Eastbourne.
updated map July 2008 (route amended Ditchling to Eastbourne & water taps)
Updated Nov. 2009 Saddlescombe water tap; also Meon Valley route revised but has become bit of mess as cannot erase old route
Following site has distances of taps along the SDW https://www.southdownsdouble.net/routeinfo.html
Detailed individual locations
a) The Sustainability centre on SDW (between Exton and QEP) (opposite the old HMS Mercury): we have a great cafe, water taps, campsite and hostel.
A) QEP (Queen Elizabeth Country Park), south of Petersfield: Behind Visitor Centre. (no map included here).
Photo below: View east towards Hill Barn
Photo below: tap east Amberley 11 miles; west is QEP, NOT Buriton Farm as on sign (farm cottage burnt down few years ago).
Plaque on tap plinth in memory of Peter Wren. Peter was tragically killed in a hit & run accident on Christmas Day in 1979. He was a very keen walker and his family arranged for taps to be installed along the SDW in his memory.
C1) Water tap near sewage works approx 500m West of B2139.
Plaque reads 'horse trough and water tap for walkers and riders'.
D) Washington A24: on grass bank, south side of tarmac lane, about 150 yds before A24.
A283 is behind timber paling fence. July 2009: lot of litter around it. July 2010: not working ? June 2011: reports just pipe out of ground? working?
photo July 2009
F) YHA Truleigh Hill: outside YHA, beside door to toilet.
G) Saddlescombe Farm (between Devils Dyke and Ditchling, about 1 mile west of A23.
See link to website http://www.southdownsdouble.net/routeinfo.html above
Photo from Jago.
Mike has kindly emailed me to say that there is a tap in the wall on the north side of A27 near the bridge which crosses over A27.
Another photo from Mike A:
Ja) Southease Church:
From R. Ouse crossing going westwards
Photos below kindly sent by Danny W.
J) Southease: in front of cottage. PLEASE NOTE: SDW is now diverted via bridge (FB on map) over A26.
So if you follow SDW sign you will miss water tap. Instead continue for 100 yds to Itford Farm and tap is on left by telegraph post in front of cottage. Neil has kindly emailed to say 'new tap on wall where SDW turns to go over bridge, but not yet operational'
Photo from Mike.
K) Jevington: Tap is easy to find, just on left as you head up path towards church. looks clean, well maintained, has "E II R" commerative plaque.
Photo from Mike.