Catch basins should be provided with gratings (Fig. 63) with ample open spaces between the bars for a free intake of all water. Small openings become clogged with leaves and are useless.
Where a large volume of water is to be taken care of it is well to build the basin back six or eight inches beyond the iron grating and place a coping stone over it, with an opening three inches wide, for the full length of the grating (Fig. 64).
Where road drainage is connected to the sewage disposal system it is necessary to have a running trap between the sewerage line and each connection with the catch basins. In this event care should be exercised to see that all pieces of pipe are free from flaws and the joints packed with oakum before cementing the sections together.
Fig. 69. - Where the ground is slightly undulating, the aspect is most pleasing if the surface is unbroken to the base of the house, with only sufficient slope to drain off the surface water. The view illustrates the charm of a lawn treated in this manner.