Sizes (d*) and weights (W*) for rockfill bottom protection
  1984 Design For refurbishment works of 2002 Design
  d50 Wd50 d10 Wd10 d50 Wd50 d100 Wd100
Sluiceway 0.50 120 0.20 45 0.75 620 1.00 1100
Gated Spillway 0.35 50 0.20 45 0.75 620 1.00 1100
Weir 0.35 50 0.15 35 0.50 200 0.75 620
*d in metres, W in kilograms