City of Placerville
Low Impact Development in Placerville: Rain Water Harvesting CITY OF PLACERVILLE DEVELOPMENT SERVICES PLANNING DIVISION 3101 CENTER STREET PLACERVILLE,CA 95667 PHONE (530)642-5252 FAX (530) 295-2510
Benefits of LID Stormwater Management Improves the water quality of streams, creeks, and rivers Reduces flood risk by reducing flow volume Recharges groundwater resources Cost Effective compared to conventional stormwater technology Aesthetically pleasing while environmentally friendly
Low Impact Development (LID) is an approach to stormwater management modeled after nature. Rain water harvesting is a LID practice that dates back to ancient times that uses stormwater runoff as a water resource. Evidence of rain water harvesting methods, such as cisterns and rain barrels, have been found in many ancient civilizations across the world and can be used still today to improve water quality and conserve water resources. What is rain water harvesting? Rain water harvesting is the practices of diverting and capturing rain water to store for later use. Using cisterns and rain barrels, the stored rain water could be used in dry months to irrigate gardens and landscaped areas, wash cars, even flush toilets. Rain water is a high quality and free source of water that could be easily implemented into stormwater systems. Why do it? About 600 gallons of water can be collected from one inch of rain falling on a 1,000 square foot roof. The City of Placerville receives an average of 38.75 inches
of rain annually. This allows for a substantial water resource available during dry months of the year. Residential, commercial, and industrial areas have the capacity to use rain water as a watering option.
These can be simple systems with a rain barrel, or more complex systems with a cistern, but all provide an opportunity to tap into an under used resource.
runoff from the roof will pour from the down spout into a hole at the top of the rain barrel with a screen over it. An attached spigot a few inches from bottom will avoid settled debris and can connect to hose, drip
line, or other system. The stored rain water is not potable, and cannot be used for drinking water.
Rain Barrels Rain barrels are a simple rain water collection system, and are readily available for homeowners and developers to install. Most rain barrels are about 55 gallons, but can range in size. Water
LID in Placerville: Rain Water Harvesting
Maintenance and Operations Installation
Install gutter guards to prevent leaves and other large debris from entering facility
Regular Check for leaks, which should be fixed promptly Check that filters are free from debris Check for erosion around base of facility and overflow outlet
Seasonal
Do not store water from the first rain of the season. Allow it pass through and wash out the built up pollutants from the dry months. Clean gutters of leaves and debris Apply heat tape or insulation to protect against winter freezing
Cisterns Cisterns are a much larger storage facility than rain barrels, and have the capacity to be much more complex. Cisterns are often located both above and underground. Plans for a below ground cistern should be taken to the Building Division to determine if a permit is required..
volume of the cistern is determined by the roof collection area, as well as how much is intended to be stored. Regardless, all cisterns should keep a size ratio that is larger wide than tall.
Cisterns must be water tight, and are generally made of plastic, metal or concrete. The size and
More Information For more information on design, maintenance, and benefits of rain water harvesting, please visit these sites. “Low Impact Development in Northern Nevada: Rain Water Harvesting” http://www.unce.unr.edu/publ ications/files/nr/2009/fs0924. pdf City of San Diego rain water Harvesting Guide http://www.hwd.com/conserv e/rainwater-facts.pdf Texas A&M AgriExtension: Rain Water Harvesting http://rainwaterharvesting.ta mu.edu/
Design Rain water harvesting is only recommended for roofs made out of tiles, plastic, or metal sheets. Roofs with asphalt shingles should only use collected water for gardening and irrigation, and roofs treated with tar or a similar substance should only use collected water for irrigation. Rain water harvesting, whether through rain
barrels or cisterns, is composed of the same components: a catchment, conveyance, and storage. Catchment is the surface where rain water is collected, generally a roof. Conveyance is the transportation, usually a gutter and downspout, to the storage facility. Storage is the rain barrel or cistern.
have a way to handle overflow in the case of a big rain. Cistern systems may also include a pump and treatment components. Rain barrels and above ground cisterns should sit on a flat, sturdy surface. Cinder blocks are a common platform for rain barrels.
Storage facilities should
Works Referenced: 1. “Low Impact Development in Northern Nevada: Rain Water Harvesting” University of Nevada Cooperative Extension, 2. “Rain Water Harvesting Guide” City of San Diego 3. “Rain Water Harvesting” Texas A&M AgriExtension Prepared for the City of Placerville by Allison Holmstedt Design Schematic provided by Paris Coyne
Works Referenced: 1. “Low Impact Development in Northern Nevada: Rain Water Harvesting” University of Nevada Cooperative Extension, 2. “Rain Water Harvesting Guide” City of San Diego 3. “Rain Water Harvesting” Texas A&M AgriExtension Prepared for the City of Placerville by Allison Holmstedt Design Schematic provided by Paris Coyne
Works Referenced: 1. “Low Impact Development in Northern Nevada: Rain Water Harvesting” University of Nevada Cooperative Extension, 2. “Rain Water Harvesting Guide” City of San Diego 3. “Rain Water Harvesting” Texas A&M AgriExtension Prepared for the City of Placerville by Allison Holmstedt Design Schematic provided by Paris Coyne