Lightly grease two baking trays.
Sift the flour, baking powder and salt into a bowl.
Rub in the lard until the mixture resembles fine breadcrumbs, then add the water and mix well to make a soft pliable dough.
Knead the dough lightly and roll it out very thinly on a floured board.
Cut the dough into rounds, using a 7.5 cm/3 in plain cutter.
Prick the biscuits all over with a fork and, using a palette knife, carefully transfer them to the prepared baking trays.
Bake the water biscuits in a hot oven (225 C, 425 F, gas 7) for about 8 minutes, or until puffy and golden brown.
Remove the hot biscuits from the trays and transfer them to a wire rack to cool completely.