CARMEL MONTEREY RAINWATER HARVESTING
Our specialty at Monterey Rainwater is building Rainwater Harvesting Systems, that are low cost, low maintenence, and highly sustainable. Rainwater catchment, as far as Carmel, and Monterey are concerned, is simply catching the rainwater that hits the roof and storing it for later use. This simple feat is performed by diverting the downspouts to channel the water into a holding tank. For the Carmel and Monterey area, our Mediterranean climate makes this process little trickier. Since it only rains four or five months out of the year, we can only catch it for this short time. But, since more than enough rainwater falls in our winter months, there is more than enough for excellent rainwater catchment, we just need a place to put it all. This means storage, and a lot of it, at least 2500 gallons to last long dry growing season. The Carmel, Monterey homeowner has pretty much the same problem as Cal-Am, just on a smaller scale. Theres plenty of water, it just all runs down into the bays.The process of rainwater catchment is straightforward enough. First, the source of the water is examined. The roof, of course is the place to start, but the location of trees, and the debris they produce, needs to be considered. The design of the roof, the hips and valleys, and how they channel water needs to be taken into account, and the gutter system becomes more important as they channel the water towards your tank.
Next, the tank site needs to be chosen. It needs to be stable then aesthetics of the tank site, needs to be considered, but aesthetics can easily be addressed by proper design,. Solutions such as using a small tank by the house and keeping the major storage further away are very effective. Also camouflaging the tank through various means, such as fencing, screens, trellises with plants, or even an artistic paint job can make the tank practically disappear.
Once in place, the tank is connected to the source. The downspout is cut, and a diverter is installed. This device has a screen filter that sends the leaves, and debris, down the old downspout and lets the clean water be diverted to the tank. These screens are self cleaning and should be maintenance free. After the screening, the water is sent to yet another component that is unique to rainwater catchment.
This fourth component is the First Flush system. It uses the first 10 gallons of water to clean the roof, allowing the first dirty rinse of rainwater to be disposed of. This is to keep the dust and pollen and anything else that builds up on the roof during the drier season from entering your tank. As more rain falls this system closes itself off and sends the cleaner water, off to your tank. The piping to your tank can be underground and with proper design, gravity can be used to send this water into your tank.
The tank is quite simple. Steps should be taken to make sure all the lower connections are seismicly safe, because a break here would mean a major loss of water. The water outlet on the side of tank is designed for multiple uses. There would be a hook up to an irrigation system, a tap right at the tank, possible connections to a second tank or even a stand pipe for fire protection. Then there’s the overflow outlet. This sends the excess water, out and away from the tank. Once the tank is full, that's pretty much it. Rainwater catchment is a logical, reliable, alternative water source, that can usually provides as much water as you can hold.
The obvious use for this alternative water supply is as irrigation for the yard and garden. But in a major crisis this could easily be treated for use as drinking water. It could also have some very valuable benefit as a water source for flushing toilets and doing laundry, but this time this needs some more investigation.
Our local water shortage is such, that Cal-Am and the Monterey
Peninsula Regional Water District have teamed up to offer a
significant rebate, to promote the installation of these systems.
They are willing to pay $25 for every 100 gallons of rain catchment
system installed, up to 3000 gallons. This comes to $625 for 2500
gallon tank. I stress to 2500 gallon tank because it' an excellent
size for residential use, and seems to be offered for a much lower
price than tanks, just a little bit bigger. These systems are very
sustainable; use no energy, last for decades, need little or no
maintenance, and with the price of water skyrocketing, they’re a
sound economic investment as well.