CLASSIFICATION OF WATER Gray water Reclaimed water Storm Water Runoff Potable Non-potable
GENERAL TID-BITS The typical landscaped yard soaks up 10,000 gallons of water a year, not including the rainwater that falls on the ground, according to the EPA. Most counties in southern states demand all new builds to mitigate stormwater and use alternative sources for irrigation 90% of Portland's rain falls during Oct.-May Portland will reimburse up to 100% of the Stormwater fee on a water bill if mitigation of storm water on site
RAIN HARVESTING Definition: Water that is collected off of a roof surface and stored in a storage container Collection surfaces: Roofs only Hardscape surfaces such as driveways, patios, and streets are too contaminated to harvest the water. Passive harvesting can be used for these surfaces Benefits: Water independence and drought protection Water supply in hard to reach areas Conservation: Resource and Financially Stormwater management Reduces urban flooding Water purity Rebates
CONVEYANCE SYSTEM 1. Roof 2. Gutter 3. Gutter screen 4. Roof washer/ Gutter head with filter screens 5. First flush diverter 6. Screen at top of tank small enough to catch Mosquito and pests out. MUST HAVE on a rain barrel. 7. Cistern / Rainbarrel 8. Overflow pipe 9. One way to have an Auto fill 10. Pump 11. Filter, UV, Charcoal, Reverse Osmosis. ONLY IF USING FOR POTABLE USE 12. Water Level Monitor
ROOFS and GUTTERS ROOF SURACES: Metal roofs Tile Composite Asphalt shingles ( Only for non-potable systems) The steeper the slope of the roof water runs off faster, losing some water GUTTERS For every 100 sqft of roof there needs to be 1 inch of gutter. Gutters should have some kind of screen on the whole system. At least a Roof washer Maintenance is a must with a system Copper gutters need to have a marine apoxy sprayed inside of the gutter
First flush Diverters CODE In all counties a first flush diverted needs to be installed on a system to divert the first 10 gallons of a rain. This water has the highest potential contaminated water. Average size for a first flush diverter is 18” long.
CISTERNS and RAINBARRELS Above Ground storage systems must be opague Rain barrels usually are 50gal. Food grade containers Barrels must have some kind of screening on it
OVER FLOW SYSTEMS Rain Gardens, Bog Gardens, Dry Creek Beds, Drywells
DUE DILIGENCE If you are burying a cistern you should consult a Soil and Structural engineer to make sure the soil will not crush the tanks and the area can handle the tanks. If you are putting a tank next to a house have a Soils engineer confirm that the soil can handle the weight of a full tank Large tanks may need braces to strap them down during wind and storms.
SCENERIO Water weights about 8.25 lbs / per gallon A 1500 gallon tank = 12,375 lbs.= 6.18 tons Drip system.5gals. Per/emitter x 200 emitters=100 gallons per hour 100gallons x 2 apps. A week = 200gals/wk 200gals/wk. x 16 week= 3200gal./ season Lawn sprinkler system 14 gal.x 20min= 280gal. x 3 apps per week= 840 gal./wk. 13440 gals. Needed per growing season
CODES AND PERMITS All Counties refer to State Ruling OPSC 08-03A Multnomah County No permits are needed for irrigation Only if you reroute or change gutters do you need a plumbers permit If you are making the system Potable (Drinkable) you will need a plumbers permit and have the BES approve the plumbing plans. The Gutter must have a roof washer/Gutter head The first 10 gals. of the rains must be diverted before going into the collection system.
CODES AND PERMITS CLACKMAS COUNTY Follows Multnomah county and the city of Portland codes and requirements No discount is offered in Clackamas if you mitigate your stormwater WASHINGTON COUNTY Follows Multnomah county and the city of Portland codes and requirements Permits needed for overflow into French drains/ infiltrationtrenches, drywells and soakage trenches
IMPORTANT NUMBERS Portlands average rainfall is 37 inches 90% of this rainfall happens October to May Most districts bill water in cubic ft. 1CCF = 748gallons 8.33 lb/gallon of water.5 lbsof PSI /Per ft of water. Volume of a round tank > 2(3.14 x r) x height x 7.48= gals.
PROCESS OF DESIGN 1. A design fee should be applied 2. Interview client 3. Site analysis 4. Rain calculator Sq ft. of surface x.623/ 1” rain= Gallons of water Gals. of water x inches of typical rainfall/ per year=Total H2O 1. Components 2. Bid
RESOURCES ARCSA www.arcsa.org America of Rain Catchment Systems of Association CONSERVE h2o http://www.conserveh2o.org/outdoors CITY OF PORTLAND>Stormwatermanagement Rain Barrel Guide (BES) Rain Barrel Guide Rainwater Harvesting 101 presentation in PDF (BDS) Rainwater Harvesting 101 presentation in PDF Rain Barrels for Irrigation Tutorial Water Efficiency for Your Home (Rocky Mountain Institute) Water Efficiency for Your Home Rain Barrel Guide State information: http://www.cbs.state.or.us/external/bcd/boards/plumbing/bo ardpack/08/20081017/Plumb_101708_VIIb.pdf
RAINGARDENS Benefits Storm water management Rebates Wild life Recharges ground water Reduces urban flooding Filters contamination
GENERAL TID BITS LID Vegetated Infiltration Basins Should drain a storm event with in 24 hrs. Mosquitoes take a minimum of 4 days to become adults after eggs are laid
PERMITS and CODES MULTNOMAH No permit needed as long as you are not changing the location of the downspout It must be located 10ft from a foundation Must have an overflow if needed CLACKAMAS Same as above WASHINGTON Jury is still out on this They suggest to fill out a Sensitive Area Pre-Screening site Assesment form
DESIGN 1. Determine how much IMPERVIOUS surface you are going to collect off of 2. Soil type/ Infiltration rate 3. Available area for the rain garden How deep it is determines how much volume of water can fit in a garden