Water System – Home Recipes
It is undeniable that water is a precious resource that is being exploited everywhere by human settlements. Especially in urban areas, there are many ways urban dwellers are interrupting the natural cycle of water – pollutants, runoffs, and overuse. While water management is heavily dependent on large-scale infrastructure, we should all understand the degree to which we impact the natural water cycle, and the potential opportunities to use water more efficiently.
Urbanization is a fast forwarding process that is not irreversible. This process means more and more people live on concentrated land and rely on the supply of water. Since water is a resource that is unevenly distributed across the world, cities with less than ample water supplies build large infrastructure to transport it , thus causing permanent alteration to the ecosystem. According to David Lorey in his book “Global Environmental Challenges of the Twenty-first Century”, “Large dams and river diversions have proven to be primary destroyers of aquatic habitat, contributing substantially to the destruction of fisheries, the extinction of species, and the overall loss of the ecosystem services on which the human economy depends. Their social and economic costs have also risen markedly over the past two decades”.
Although water has the ability to replenish itself, our great demand and occupation of urban land makes it impossible for natural water to catch up. A whole natural cycle of water comes from rainfalls, and return back to ground water through evapotranspiration, infiltration, and runoff. However, urbanization has largely disrupted the process. Impermeable surfaces used for streets and other pavements completely altered the natural cycle of runoff. Pre-urbanization, over 80% of the rain water gets infiltrated through soil into streams and bodies of water. In modern urban area, where most open surface is built in impermeable surface, only 20% or less of rainwater gets absorbed by soil. Most of the runoff goes directly to the large water system. Thus, when facing storm, overflow of polluted and untreated water severely pollutes the natural water and a significant degree of such pollution causes permanent damage.
Many cities started to adopt new or updated water infrastructure to solve our water crisis. In the United States, such effort is commonly known as low-impact development (LID); in Europe, it is known as integrated water management system; and in China, recent focus is paid on delivering sponge cities that prioritize minimum impact of urban development to natural water system. All these are effective initiatives in the long-term. However, large infrastructure projects cost investment and time which could not be afforded by the deteriorating water system on our planet. While we struggle with implementing large infrastructure, there are a few small steps that local municipalities or even individual households can do to reduce the impact:
Blue roofs refer to a roof setup with spongie materials and basin-like design that catch and hold stormwater temporarily. By installing blue roofs, large stormwater gets captured and slowly released to the drainage system. Such practice slows down the water runoff, thus significantly reduces the risk of polluted water goes directly into the natural source.
A rain garden is a planted blue roof, which allows rainwater runoff from impervious urban areas to be absorbed. Similar effects of reducing runoffs, erosion, flooding, or pollution is achieved by such installation.
- Rain Water Collection (the easiest of all)
Rain water could also be collected and reused directly in a household. Instead of installing blue or garden roofs, collecting rain water with simple steps could reduce the risks of stormwater runoffs and also recycle and reuse the water collected. A simple design that everyone can follow can be found here.
Start with a small intervention at your home and get to understand the future of water infrastructure on a large scale. We should all take steps to minimize our impact on our precious water resources.