A Drainage System has 3 basic parts. They are the: 1. Intake Point, 2. Transition Stage, 3. The Exit Point
The, " Intake' part of a Drainage System is usually located in the ,"Problem Drainage Area" at it lowest point. This is where water is taken into the Drainage System through some type of Drain or Gutter. A French Drain or a Surface Drain are the two most common intake Drains. A French Drain is a trench that runs through the Problem Drainage Area. The French Drain Trench usually runs one or two feet deep but can be deeper or more shallow depending on the need. In most cases a trench liner is placed in the trench. This is necessary to maintain the integrity of the French Drain Trench. A perforated French Drain Pipe is placed on top of the liner and runs to the, "Transitions Stage."
A Surface Drain is also used as an Intake point. A Surface Drain is a basin with a square or round grate on top. The Drain Pipe that is connected to the Surface Drain or French Drain begins the Transition stage. Simply put, for water to get into a Drainage System, it must pass through either a French Drain or a Surface Drain.
A French Drain is designed to handle large amounts of water over a large area. A Surface Drain is designed to handle smaller amounts or water that is more centralized in a smaller area.
A French Drain takes in Surface Water and Sub-Surface Water(water flowing underground). A Surface Drain can only take in Surface Water on top of the ground.
The Transition Stage is where water travels out of the French Drain or Surface Drain and into a Solid Drain Pipe. The Solid Drain Pipe takes the water to an Exit point or another Problem Drainage Area. Several French Drains or Surface Drains can be connected in any combination. This is determined by the needs of the next Problem Drainage Area that is farther down the hill. The limiting factor is the size of the Drain Pipe between Drains. The greater the number of Drains that are connected together, the larger the Solid Drain Pipe must be between them. Surface Drains induct small amounts of water into the Drainage System. If you have a large 6 inch Drain Pipe, many Surface Drains can be connected together on their way to the exit point. French Drains Take In larger amounts of water faster. As a result, only a Few French Drains can be connected together on their way to the exit point. French Drains and Surface Drains can also be connected together by one Drain Pipe.