Rainwater Harvesting: A Reliable Alternative in the San Juan Islands
Northwest Water Source P.O. Box 2766, Friday Harbor, Washington Office and Home 378-8252 e-mail email@example.comSpecializing in water conservation since 1992 Rainfall Catchment Rainwater Harvesting A reliable alternative water Source And stormwater solution
New ConstructionRainfall Catchment/Harvesting is approvedfor permitting new construction in SanJuan County as a sole source includingpotable.Rainfall Catchment is cost competitivewith conventional water sources.Water quality from Catchment is oftenbetter than well water in San Juan County.
Cost effectivenessRainfall Catchment is generally 150% thecost of conventional well systems.Rainfall Catchment is generally less than50% the cost of seawater desalination.Seawater desalination may only be donedirectly from the salt chuck. Thesesystems be may not connected toexisting seawater contaminatedwells.
Environmental ImpactRainfall catchment has” a net positiveimpact on ground water supplies.Rainfall catchment reduces storm waterrunoff from impervious surfaces by storingthe water.Water impounded is reintroduced to theaquifer during dry summer months ratherthan only during rainy season.
Residence of Andy and Judy Hengesteg San Juan IslandThe following system has been inplace for 4 years. This system is the sole residential supply. 14,000 Gallons Storage
San Juan Island home using rainwater harvesting as it’s sole water source. 14,000 gallons of storage located lower than house. Approximately 3500 square feet of collection area.
Can you find the storage tanks in this slide?6 @ 2340 gallon tanks located on naturally screened pad.
Easy to screen, easy to hide storage tanks 14,000 gallons
Early Filtration and Ultra Violet disinfection systemHomeowner has also added battery backup and charger on left.
1999 remodel of 4500 square foot homePotable well system declining in capacity new metal roof for collection
20,000 gallon steel storage tank with 45 mil poly linerlocated 60 feet above home, nearly invisible from home 23 foot diameter X 7 foot wall height
240 Gallon underground “ball” storage tankwith pump to transfer rainwater to storage
6000 gallons storage located under pocket deck on opposite side of house
6000 storage located under second floor deck on opposite side of house
5000 gallon PVC bladderlocated under master bedroom irrigation for sitting garden
Extensive remodel of log home in Victoria Valley very limited wells with Barium contamination30,000 gallon steel storage tank located lower than home site to enable gravity collection. New metal roof system
All downspouts connected to 4” PVC manifold. Manifold drops into 250 gallon filtration tank at lower corner of deck.Water gravities 250’ to steel 30,000 gallon storage tank
30,000 gallon storage tank with 45 mil poly liner pressure system located adjacent to tank 23 feet in diameter X 9 feet wall height
Spring Point, Orcas Island Metal roof system6000 gallons of storage located in crawl space Irrigation only
6000 gallons of storage located in crawl space below deck on right side of house
3 1440 gallon tanks and 1 1100 gallon tank under guest bedroom
Rainfall Catchment Systems Located on Lopez Islandhave been required due to Salt Water Intrusion
Grant/Allen Residence This residence has a seawater intruded well that exceeds 250 ppm. A well drilled on the adjacentproperty also exceeds the Chloride limit. 20,000 Gallons Storage
New system presently installed fall of 2000 20,000 gallon steel tank with poly liner metal roof system
All 4 inch PVC collection manifold is located underneath existing decking. Collection system is invisible
20,000 Gallon tank located adjacent to home. Tank filled in less than 3 months.
Large collection area will ensure enough for household use some irrigation will be feasible. Good source for fire protection
Details of filtration,disinfection and pumping system
Residence located at Mud Bay, Lopez IslandSteel roof system designed to discharge to a single downspoutpump located in culvert tank, pumping 60 feet uphill to remote storage 9,000 Gallons Storage Capacity
Water side of Mud Bay homestorage tanks are not visible from home
Mud Bay HomeRemote storage tanks above home site, 9000 gallons system was required for building permit
Molitor home on Shaw IslandWell failed in capacity due to overdraft by neighbors.
3 2340 gallon tanks under trees barely visible just to the right of the porch.
Fisherman’s Bay Peninsula , Lopez IslandTemporary Mobile Home to be used during construction. 4600 gallons storage behind screen to left. System required for building permit
Fisherman’s Bay Peninsula, Lopez Island4000 gallons in 4 box tanks located under deckmetal roof system, required for building permit
4000 gallons of storage hidden below deck Fisherman’s Bay Peninsula, Lopez Island
Bakerview, Lopez Island Modular home installed with 4600 plastic catchment tanksystem required for building permit because of salt water intrusion
Bakerview, Lopez Island 4600 Plastic water storage tankbottom set 24 inches below grade
Greywater GreenhouseMiller residence, Lopez Island
Greywater Greenhouseviewed from inside living room
Savage/Wooten residence, Shaw Island Dual system potable from wellall other water from rainfall catchment
Collection tank with pump to transfer to storage tanks, remote on property.
8,400 gallons rainfall storage 600 feet from house
Potable and non-potable pumpstank on left is storage for potable well
Lopez SchoolLopez School has been supplied from a distant well for several years. Due to concern with Salt Water Intrusion, Northwest Water Source is designing a rainfallcatchment system for total use of the school complex.Washington State Department of Health will allow the design if treatment meets drinking water standards.There will be a 120,000 gallon raw water tank located elsewhere on the property. Filtration will be by “Bag Filters”, with both Ultra Violet and Chlorination for disinfections. School buildings will produce over 1.5 million gallons per year.
Installation of 240 in-ground ball tank to collect water from rooftop and house deep well pump to shuttle water to 20,000 tank above house
Construction of steel tankFoundation of crushed rock and compacted sand with cement pavers for support of steel tank
Liner Installation. All Fittings through floor
San Juan Island Fire Dist. 3San Juan Island Fire District #3 is building a new 9000 sq.ft.firehouse. They have an excellent well, but have decided to fill their new 30,000 gallon water storagetank from rainfall catchment. Thestorage tank if for fire truck water supply and building sprinkler system.
New 9000 sq.ft. firehouse with storage tank located behind building.
Existing house, Port Stanley, LopezIsland due for remodel summer 2002.Well has been contaminated with sea water. Will do metal roof and catchment.
Rainfall InformationYou may use the average rainfallfor selected locations in San Juan County to complete the above worksheet. Average water use per person/per day is 50 to 60 gallons. There is no allowance for irrigation which is generally not recommended .
Rainfall Catchment Water Budget You may use this worksheet toestimate storage and catchment area requirements to suit your needs
Rainfall Catchment Water Budget for Feasibility Number of Users 2 Gallons per day/person 50 Supplement from well 0 STEP 1 Gallons required per day 100 (users x gpd/p =) Days in residence/year 365 STEP 2 Total water use per year 36500 (gpd x days =) Rainfall 22 Water per sq.ft./inch of rain 0.623 STEP 3 Gallons water/sq.ft./year 13.706 (rainfall x .623 =) Total water needed per year 36500 Gallons water/sq.ft./year 13.706 STEP 4 sq.ft.collection area needed 2663 (water needed/gpsqft =) Days storage required 90 Gallons required per day 100 STEP 5 Gallons of storage required 9000 (days stg x gpd =)System requirements for the above system are as follows Rooftop catchment collection area required for this design based on rainfall in the surrounding neighborhoodREQUIRED 2663 sq.ft. Storage capacity required to supply system for periods without rain (summer)REQUIRED 9000 gallonsROOF TOP COLLECTION AREA Sq. Ft. Main House 2700 Studio Garage TOTAL COLLECTION AREA PROVIDED 2700 TOTAL WATER AVAILABLE ANNUALLY 37006 TOTAL WATER STORAGE REQUIRED 9000
Average rainfall at selected locations in San Juan CountyAll roofing material to be enameled metal or other approved impervious surface.Average Rainfall by location South Lopez 15"/yr South San Juan 18/yr Fishermans Bay 20"/yr Friday Harbor 22"/yr Central San Juan, North Lopez 24"/yr Shaw, Henry, Crane 26"/yr Roche Harbor, Orcas Landing 27"/yr Deer Harbor, West Sound, West Orcas 28"/yr Eastsound, Buck Mt., N.W. Orcas, Waldron 29"/yr Olga, Pt. Lawrence, Obstruction Is. 32"/yr Northshore Orcas, Mt Constitution, Twin Lakes 35"/yrNorthwest Water Source dba Greywater Management, Inc. Friday Harbor, WashP.O. Box 2766, 378-8900, fax 378-8790……….e-mail..firstname.lastname@example.orgDirections for use of this work sheet.Choose the average rainfall from the listing at the bottom of page oneadjust the variables (red figures above) for your conditionsnote requirements (blue figures above) to size your systeminsert planned structures (green figures above) to determine whether the proposed structureis of adequate size to supply required water. Don"t downsize storage required if you havemore than adequate roof footprint.roof pitch has no bearing on catchment area except in areas of high wind during storms.All math formulas are already in this worksheet. If you change the variables, the required totals willautomatically change with them. If you have any questions, Call Tim Pope at 360-378-8900 or evenings a360-378-8252. Happy water prospecting!
Documents required by San Juan County, Washington forbuilding permit for new home using Rainwater Harvesting as a sole source including Potable.