11.   They were digging a drainage ditch.

12.   It moved slowly towards the drainage ditch.

13.   Much of it is below sea level and only innumerable drainage ditches prevent it from reverting to its natural state.

14.   The drainage ditches were dug with spades, the ploughs drawn by horses or oxen.

15.   Farm drainage ditches ensure that water runs directly into streams rather than being filtered through the soil.

16.   At one stage the whole congregation went outside to see where the drainage ditch would be sited.

17.   Sluices are being repaired on the drainage ditches to raise water levels and create wetland... a valuable and increasingly rare habitat for plants and animals.

18.   The reason -- the drainage ditches flooded and water overflowed down the main street.

19.   And as he trotted toward the bridge, he fell into a drainage ditch and was drenched.

20.   And others depict haze drifting through a monstrous canyon, Valles Marineris, beside which the Grand Canyon would resemble a drainage ditch.