There was some recent discussion about "drafting basins" in our Members Area Discussion Forum so we thought we would show a couple of photos about the basin concept. Of course, terminology can vary from locale to locale, but traditionally a drafting basin is an area where FD drafting operations can occur without the need for making a connection to a suction head and the water supplied comes from a natural source such as a pond or stream. A common style of drafting basin uses large culvert pipe and a manhole-style access point to receive water from a pond. Pond water travels through the culvert pipe and a FD pumper can draft via the manhole access.
Generally, the drafting basin concept works well as long as the culvert pipe is large enough to not restrict natural flow currents and the lift at the manhole access is not excessively high. This means using 16-inch or larger culvert pipe and trying to keep lift at or below 10-feet. The other important part of this operation is routine maintenance on the culvert pipe - meaning that sediment buildup must be controlled. A public works vacuum truck used to clean out storm water drains should be used annually to remove sediment and debris build-up in the basin and culvert pipe. The other important item deals with design, the culvert pipe should have some type of large screen over the end in the pond so that aquatic life does not take up residence inside the pipe.
A few photos of a drafting basin are shown in this News Story. They are from a water supply study that we completed in Clinton, Connecticut a few years ago. There are a number of drafting basins in use in Clinton, CT and some of them were part of the original design of the developed area.