. . . wading pools
These pools, being built for children, should never be very deep. Depending on the age of the child, they may vary from 12 to 27 inches tapering upward to 6 to 9 inches in depth. Small children should never use them without the supervision of an adult; so that it may be well to place the pool where the parent can see it from the house. Five by seven feet is a suggested size, but any size which you find convenient may be used. If you plan to use the pool later on for plants, you may want to check the recommended depth for water lilies and make the deep part of the pool that depth. If it is deeper than you think is safe for your child, fill the pool only part way. A wooden cover may be made to place over the wading pool when it is not in use to prevent children from wandering into your yard and using it without supervision. Small children can have accidents very quickly and it is well to foresee them. The cover will be useful later on as a winter covering for the pool when it is drained.

. . . pool overflow and drainage
To prevent the pool from overflowing (and even those with no jet or regular source of supply may catch rain water and need drainage facilities when they overflow), some provision must be made in the form of an overflow channel or a removable pipe which screws into the mouth of the regular drain. This pipe should have a strainer or screened cap to prevent the entry of leaves or other debris which would clog the drains. Overflow pipes are best made of brass, as should be the fittings and piping of the pool. This lasts indefinitely without corroding, and it never will rust, of course. The overflow pipe should be just long enough when screwed into the drain to reach the level at which you desire to have the water remain. (See sketches of overflow pipes in the plans.)