Liquidambar specializes in transforming ordinary or difficult sites into gardens that blend function with aesthetics. We use subtainable landscape practices that nurture the soil, conserve water and energy, and recycle or repurpose your materials. Transforming small challenging urban spaces is our specialty.

02 May 2010

Water Water ... Everywhere?

Recent rain storms might have you thinking we’re now over the three-year drought. Snow-pack is above normal for this time of year, reservoirs are filling up. But like the skeptics who believe the east coast snow storms disprove the ‘inconvenient truth’ of climate change, our water shortages are not replenished with just one wet winter. Without immediate action, California residents by 2015 will be consuming more water at current usage rates than will be available, regardless of future rains.

Effective January 2010, new state water regulations seriously impact the allowable use of water for landscaping (see link below: CA State AB 1881 - WELO - Water Efficient Landscape Ordinance). While these regulations may not directly affect many small urban gardens, they do provide a useful guide for people trying to plan for future conservation, because by 2020, California will require all residents to reduce overall water use by 20 percent. And in case this is not obvious, this legislation is telling us we face tighter supplies, and consequently, significantly higher water costs. It makes sense to start with this reality.

So what can we do now to prepare. One simple way to reduce water consumption is to harvest rainwater. Rainwater is harvested by redirecting down-spouts and gutters into water-tight barrels to which your irrigation system can be attached to run exactly as it would from your tap. In addition to watering your garden, rainwater also can be used for bathing, flushing toilets and washing laundry. Salvaging rainwater protects the environment as well as minimizing waste and costly treatment systems: Runoff water is a major source of pollution in San Francisco Bay, as it makes its way over toxic rooftop materials and oily streets into storm drainage systems.

Numerous resources are available on-line to demonstrate rain-barrel installations for the do-it-yourselfer (see links below). For the not-so-handy, rain barrels can be discretely designed into your new landscape (hidden under decks, screened with plants or trellis); or they can be added later as part of on-going maintenance. And if your budget prevents purchasing high-end designer tanks, other options are available for the resourceful homeowner. Some garden centers and hardware stores also sell barrels. Be aware: all rainwater storage units need to have a first flush diverter (literally, to clear debris from the initial water flow); a strainer to prevent dirt getting into your container; an overflow devise when the barrels fill up. And for functionality, containers are best elevated on concrete blocks or similar. It is critical they be water-tight and screened to dispel mosquitoes.

If properly harvested and stored, rainwater also is drinkable, but only if the containers are food grade (think earthquake preparedness!) As long as your roofing material is non-toxic, rainwater flowing off it is drinkable.

An alternative or adjunct to harvesting rainwater is to reclaim household ‘grey-water’ from the clothes washer, shower and/or dishwasher. This is more complex and may require the services of a plumber and in some areas, a permit. If these options are not viable for your space or the footprint of your home, another way to minimize waste while promoting healthier soil is to create a ‘rain garden.’ Essentially a retention basin, this shallow depression initially contains rainwater that is directed from gutters and down-spouts. As it percolates into the soil, the water is filtered of impurities, thus preventing polluted runoff from entering the municipal water system and the Bay. Properly designed, these areas can be incorporated into your new or existing garden and planted with appropriate trees, shrubs and perennials. Where space allows, they can be designed to look like wet/dry streams, swales or water-features.

As with rain gardens, the issue for most San Francisco Bay Area homeowners typically is space, or lack of space to store the rain barrels. Even if you have space for just one or two containers, these can be replenished in the dry season with water salvaged from the shower as it runs ‘till it’s hot. Possibly the simplest water-conserving method is to plant drought-tolerant natives, succulents and climate-appropriate plants that require minimal or no water once they become established. A responsible plant selection can produce a lush, luxuriant garden, as green as the once-favored lawn without the consequent hazards of pesticide use, oil-powered mowers and wasted water.;]