Collecting rainwater offers numerous benefits for your budget, cultivation, and the environment as a whole. However, there are important considerations to keep in mind when installing a rainwater collection system, whether it’s a barrel in the garden, next to your property, or on the roofed terrace.
Even an improvised, uncovered container for collecting rainwater and its use for additional irrigation is better than having none from both ecological and economic perspectives. This is particularly true for properties without gutters or roofing made of materials like eternit, asbestos, or asphalt. However, for operational and safety reasons, commercial rainwater collection systems with upper lids, which protect children and small fauna and eliminate the threat of mosquito breeding or rotting of contaminated leaves, are more suitable.
It’s Up to You
Handling industrially produced retention tanks with features like volume, material, surface, shape, and color design is much more practical. These tanks often come with drain valves connected to a garden hose, overturning anchorage, and overflow protection. They are easier to store for the winter to protect against damage from freezing. Additionally, they have an antifungal finish, are UV-resistant, easy to maintain, aesthetically unobtrusive, and fully recyclable.
Sufficient Volume
A strong argument in favor of modern collection barrels connected to the vertical gutter drain is their volume. In Central European regions, it’s necessary to continuously collect rainwater in one or more containers with a total capacity of approximately 700 liters to support additional watering of one acre of land with mixed vegetation (utility and ornamental beds). Even the largest conventional barrels, typically with iron hoops covered and round planks without a lid, do not hold more than 500 liters.
Size of the Roof Matters
The volume of the rainwater collection system depends on the size of the roof as well as the container or system. Above-ground tanks made of robust plastic with a metal reinforcing envelope can hold up to 1,000 liters. For larger-scale water storage, up to 10,000 liters, recessed water tanks with inflows from the gutters introduced beneath the terrain, along with pumps for distribution, are suitable, although more appropriate for large-scale growers than hobby gardeners.
Onion and Cauliflower Are Different
Keep in mind that different crops have significantly varying water requirements. While 50 liters of supplementary water per square meter may suffice for onions during their growing season, cauliflower may require up to six times more. When maintaining a lawn, the water consumption is even higher. A square meter of lawn can consume approximately 700 liters of additional irrigation per year, which has a financial value of EUR 100 per square meter.
Calcium-Free Irrigation
One significant advantage of rainwater collection is the substantial reduction in water consumption from the public supply. This cost-saving can easily offset the setup expenses for your rainwater collection system. Moreover, it benefits your crops and decorative plants by providing water free from calcium and chemical components typically found in tap water. By relying on rainfall for irrigation, your vegetation receives only calcium. Any additional calcium needed can be purposefully provided in a form other than tap water.
It’s important to note that the Ministry of Health recommends a concentration range of all multivalent cations of alkaline earth metals, particularly calcium and magnesium, at 1.1 – 5 mmol/l. However, for plants, the critical upper limit is already 3.75 mmol/l.
Text: Miki Kočan ml., photo: unsplash.com
