Where do greenhouse businesses fit? Consider this: the actual production area on a site might only be 60 per cent of the total land area (often reflecting local bylaw restrictions). If water is the new oil, what can be done on the remaining 40 per cent of land around the farm that is not related to water application, but nonetheless affects water use? Enter the landscape industry and “rain garden” designs.
Incorporating water retention features has several potential benefits:
- Promoting planting and reducing monoculture areas (e.g., mown turf).
- Enhancing wildlife.
- Increasing biodiversity.
- Reducing paved areas, and reducing herbicide use.
- Providing visual and sensory pleasure – they can look and smell good.
- Providing play areas for kids – children love water areas! (Caution: while encouraging play, considering safety around water areas is essential. Also, be careful not to develop stagnant patches of grey water that may harbour diseases.)
- Generating a positive effect on microclimates – water helps keep the area cooler during summer.
- Reducing soil erosion caused by high volume runoff.
- Potentially reducing maintenance costs of the site.
- Rain garden concepts can be designed into a number of areas around the farm:
- Areas with downspout channels immediately alongside the home and other buildings (sheds, workshops, barns).
- Hard-standing areas (car parking, machinery storage yards, driveways, etc.): “High levels of hard standing surfaces in cities mean 56 per cent more rain produces 82 per cent more run-off” (Prof. Handley, Horticulture Week, April ’08).
- Riparian areas alongside fields.
- Natural water retention areas.
- Drainage channels.
The obvious one is the use of grey water: untreated household waste water that has not come into contact with toilet waste. This includes water from baths, showers, handwash basins and from washing machines. (Water from kitchen sinks and dishwashers is more of a problem). This water could be useful for irrigation.
Bioretention is another potential design to conserve water. Simply put, a bioretention system provides a way of runoff collection, filtration, storage and subsequent uptake by plants. Apart from saving (or at least not wasting) water, this system might also reduce fertilizer runoff from the site.
Stormwater retention: Most greenhouse operations collect rainwater from the greenhouse roof. But how many collect runoff from the home or out buildings? Installing rain barrels could reduce the property’s “water footprint” (think water consumption, like “carbon footprint”).
Disconnecting down-pipes and incorporating more esthetic drainage channels produces landscape swales, which can be vegetated channels, or simple linear depressions, temporarily storing and moving runoff water in aesthetic ways. Suitable locations are around car parking areas or along transportation corridors, such as frequently travelled pathways.
Green roofs are relatively new concepts in North America – the deliberate planting of vegetation on specially constructed roofs. However, they have been used for some time in Europe. The Ford Rouge Dearborn green roof in Michigan, at 10 acres, is the largest in the world. (Ford did it just because it saves them money!) Another six-acre roof is being installed atop the new Convention Centre in Vancouver. These are changing the face of urban landscapes, reducing water runoff and erosion, keeping buildings cooler in summer and warmer in winter, thereby reducing energy consumption and reliance on fossil fuels. So, how about a green roof on the pack-house, or on the storage shed?
Failing a full green roof, consider stormwater planters, simple above-ground planting containers that intercept water run-off from building roofs.
Give it some thought. What can you do to reduce your water?
ı From Rain Gardens, by Nigel Dunnett & Andy Clayden, Timber Press (2007).