You need to identify the sources and paths of water flow, the potential flood hazards, and the environmental impacts of the drainage system. You can use tools such as maps, surveys, geotechnical reports, and hydrological models to collect and analyze the site data.
The first step to designing your drainage system is determining the area that you need to drain. You'll need to map out your property and identify all areas where water accumulates most. Once you've identified drainage areas, you can start designing the system.
All pipes should be laid in a trench that is 300mm wider than the pipes themselves. In addition to this, all plastic pipe runs need to be laid on a 10mm layer of pea shingle or fine gravel. This will provide a base for larger grade material and backfill to be placed on top later.
Drainage field construction
Pipes should be laid on a 300mm layer of clean shingle or broken stone (graded between 20mm and 50mm) at a minimum depth of 500mm and a uniform gradient not steeper than 1:200.
Use Slopes to Achieve Optimal Drainage Conditions
According to the EPA, patio slabs, walks and driveways need a minimum slope of 1/4 inch per foot away from the house with back-fill to prevent settling. The final grade must be sloped away from the foundation by 1/2 inch per foot over a minimum distance of 10 feet.
While there are many different types of landscape drainage systems available, these three primary systems are some of the most common and effective solutions. Dry wells, French drains and downspout/sump connections all help to prevent stagnant or pooling water with their respective strong suits.
Approaches vary by LPA, but a typical drainage strategy usually defines: the site's characteristics (slope profile, soil geology, existing flood risk) the calculated surface water runoff rates and required storage volumes.
Once you start digging your drain depth will need to be anywhere from eight inches to two feet, depending on your needs and available options.
Drainage Patterns. Drainage Pattern is the pattern formed by the streams, rivers, and lakes in a particular drainage basin. The pattern created by stream erosion over time reveals characteristics of the kind of rocks and geologic structures in a landscape region drained by streams.
The system is required to collect and transport sewage water from the kitchen, toilet, and bath area. The roof of the house must have enough headroom to handle the surplus rainwater. Also, the outdoor gutter systems installed at the house must be properly sized to carry away all the wastewater.
Direction: According to Vaastu, the ideal direction for the drainage system is towards the north, east, or northeast. These directions are believed to be auspicious and promote positive energy flow. Avoid directing the drainage towards the south, west, or southwest directions as they are considered inauspicious.
Residential sewer line pipe depths range from as shallow as 18 to 30 inches in depth or 5 to 6 feet deep. However, in colder climates where freezes occur, you often see sewer line depths ranging from 4 to 8 feet deep. This ensures the pipes are below the freeze line.
Hiring a professional to install a yard drainage system will cost between $50 and $100 per hour. Most projects take 12 to 72 hours, bringing your total cost to $600 to $7,200.
Desired slope: To achieve the best drainage solution, you must create an incline in the yard with a slope as small as 3% or as severe as 25%. Distance from the house: The furthest area from the house or building structure should be the lowest point in the lawn to maximize water drainage away from the foundation.
The ideal slope of any drain line is ¼ inch per foot of pipe. In other words, for every foot the pipe travels horizontally, it should be dropping ¼ inch vertically. Many drains either have too little slope or too much slope.
Design and Construction
Drainage fields should be constructed using perforated pipe, laid in trenches of a uniform gradient which should not be steeper than 1:200. Pipes should be laid on a 300mm layer of clean shingle or broken stone graded between 20mm and 50mm.
Adding 2 to 3 inches of topsoil should be fine, but more could be a problem. Second, the plants need to be rela- tively low-maintenance and low- water use. It will be best if you select plants for your drainfield that, once established, will not require routine watering.
For efficient drainage, paved surfaces should have a minimum 1-percent slope. Turf or landscaped areas should have a minimum slope of 2 percent.