It's not nearly as much fun harvesting rainwater in a drought as it is when it's raining . . . but it can be done We are not engineers or professionals, and we’re not here to sell anything – we’ll basically just show you how our system is set up and describe some areas we might have done differently if we knew then what we know now – we hope you can benefit from our mistakes We bought our land in 1995 and started building in 1996 – so we’ve been collecting rainwater for over 14 years – no well We don’t make any particular recommendations for systems or suppliers – but we will mention some names for additional information and help Ask how many already have some kind of collection ? MNs – Peña, Stanley, RNC, Clyburn, Sawin, Collins, Y Carlyle, Jim & Janet Lindley, Reidun H,
Texas’ population is projected to more than double to about 45 million people by 2060, with much of that growth projected in the Hill Country area More than 57,000 more people are coming to live in the Hill Country every year. The 17-county region’s current population of 3.1 million is projected to climb to at least 4.3 million by 2030.
Acceptable roof types: Metal – galvalume (55%aluminum, 45% zinc alloy) Clay or concrete tiles – but may contribute to a 10% loss due to texture, inefficient flow, or evaporation Composite – not appropriate for potable systems Slate – OK but expensive
Dan Note vinyl window screens at downspouts Gravity-flow system – flows from gutters to tanks, then back to pump Point out components: Catchment Conveyance Storage Filtration/purification
Use footprint, not actual surface area
Most common: half-round PVC, vinyl, pipe, galvanized steel seamless aluminum – more expensive Vinyl: Relatively easy to clean, doesn’t need painting – Plastmo available in different colors (show sample) Note roof design lends itself to very simple guttering (happy accident – not what we had in mind when designing garage)
Tanks must be level! Our system – built in multiple phases, with multiple inlets and multiple filtering mechanisms Doesn’t have to be so complicated – plan, and keep it simple! Preferable to use fewer tanks Our tanks are polyester resin-lined fiberglass – tank at Riverside is polyethylene (?) ~ $3100 for 5000 gal
In addition to screens over downspouts, there are two basic types of first wash systems: capture type – either a tube or tank – price varies from $25 to $1200+ – PVC pipe in photo ~$25 + labor All of the first wash systems require attention after each rain event of any size – filters must be kept clean or system will clog up, back up, and overflow
tank type of first wash ‘ Booley eliminator’ from Tank Town in Dripping Springs – top of the line ~$1200 + installation
The vortex rainwater fine filter is typically installed in the underground piping system to remove debris from the storm water system.Used in installations where multiple downspouts are connected together to a single pipe into the vortex filter. The vortex rainwater filtered water can be used for site irrigation, toilet and urinal flushing, janitorial use, laundries, fire protection, evaporative cooling tower make-up, process water or other non-potable uses.
Also – filter boxes or barrels – example of this on Riverside’s system – ~$50
Additional filtering option for use in tank – filters water drawn from 12-16” below surface, where the ‘best’ water is thought to be Kits for this filter ~$450 Must have special ‘full-through’ coupling on your tank
combines a pump, motor, pressure tank, and controller into one integral unit 1HP pump is self-priming, with built-in check valve Built-in overheat and dry pump protection Maximum 17 gpm at a constant 55 psi Specifically designed for drinking water applications – expressly approved for use with rainwater - ~$600 Grundfos: Danish company founded in 1945
5-micron sediment spun-fiber filter 3-micron activated charcoal filter – 9 gpm two ball valves permit two pressure gauges: one to measure incoming pressure, one for outgoing pressure – by monitoring difference in pressure, you can tell when filters need changing rule of thumb: change spin filter monthly, charcoal filter quarterly spin filter shows when it needs changing ~$325 for filter assembly
Available as pre-plumbed setup with pressure gauge and ball valves, mounted on plywood over a galvanized steel panel ~$2000
Provides extra protection in the event of a fire – ready supply of water May be eligible for discount on homeowners insurance Check with your own fire dept for correct size
Phyllis This is the first question everyone always asks . . . No voodoo, just arithmetic. Depending on rainwater means having enough storage to collect lots of rain when it does rain. You need to have enough storage capacity to get you through the longest (historic) period with no rain – ~100 days in this area. Then figure your usage – we estimate ~100 gal/day, so 100 days with no rain means we should be able to get by with 10,000 gallons storage.
For our area, figure on 100 days with no rain Drought of record: worst year had 12” total rainfall Last few years in Hill Country: ~15” in 12-month period On land: 1” rain -> 27,154 gal/acre (208.7’x208.7’, or 43,560 sq ft)
based on our system, adjusted for today’s prices
Phyllis - Now required on new buildings >2500 sq ft in Santa Fe - Was illegal in Colorado until 2009 – now OK with restrictions - Illegal in Utah and Washington unless landowner has water rights
Toilets – approx 30% of all indoor water use Use low-flush toilets – 1.6 gal New toilets with two flush options Check for leaks – food color in tank, wait 15 minutes – if bowl is colored, flapper may need to be adjusted or replaced Running water in bathroom and kitchen sinks Turn off water while brushing teeth or shaving Rinse dishes and vegetables in pan of water rather than running water Compost food scraps rather than running garbage disposal When replacing an appliance, but a water-efficient model that offers different cycles and uses less energy Landscape can account for 20-50% of residential water use ideal application for rainwater collection! Filtering not necessary reduce turf areas – easier to maintain and lower water use keep a height of 2.5-3” on grass areas – protect roots from heat stress, reduce loss of moisture to evaporation plant native and well-adapted plants that won’t need to be watered once they are established Drip irrigation more efficient than sprinkler If building, consider adding circulating pump for hot water
Cloud Juice samples other MNs doing presentations on rainwater collection: Jim & Priscilla, Sandy & Raul also – Billy Kniffen, John Kight each one is different, so try to hear any/all of them
Rainwater Harvesting in a Drought Dan Behringer & Phyllis Muska Texas Master Naturalist – Hill Country Chapter October 26, 2011