Although rainwater collection systems facilitate sustainable living by means of reducing a household's reliance on water service providers, it may not be as practical when implemented on a larger context. Stormwater collection for an entire community requires years of planning and construction to effectively set an adequately functional rainwater management system in place. Several personnel must be tapped to construct the various well placed catchment areas, dependable conveyance mechanisms, massive storage facilities, efficient distribution mechanisms, and most importantly, effective purification facilities.
Not too many communities have the financial capacity to install rainwater collection systems. As such, they opt for traditional methods when handling stormwater—the construction of sewage systems, floodgates, dams, and other methods of preventing rainwater from becoming stagnant or eliminating it altogether. Fortunately, there is a natural approach to managing stormwater without setting up elaborate mechanisms and maintaining expensive facilities. Passive stormwater management systems collect and divert rainwater to sustain landscaped areas.
Passive stormwater management systems make use of various methods to channel rainwater into areas where "green" water levels need regulation. Passive stormwater management systems could use swales, microbasins, rain gardens, French drains, permeable pavements, and curb and road grading design to effectively divert rainwater to areas where it is needed most. A passive rainwater collection system emulates the natural hydrological cycle, which could efficiently support vegetation, augment groundwater recharge, and reduce erosion and flooding.
Microbasins are miniature catchment areas where small amounts of rainwater could be collected. Differently, storm water systems with swales divert rainwater from buildings. Swales' sloping configuration diverts rainwater from low to medium downpours. French drains and rain gardens facilitate quick collection of stormwater, especially during heavy downpours. French drains lead rainwater to several storage tanks while rain gardens collect stormwater and channel them into a central storage unit.
Storm water systems with permeable pavements allow rainwater to pass right through them, expediting rainwater collection. The diverted stormwater is transferred to sand or gravel sub-base layers which ultimately lead to natural soil layers. Parking lots can be designed to have various grading elements to channel rainwater into landscaped areas. Stormwater can be directed to flow right into depressed areas where it can enter and subsequently seep into exposed natural soil.
However, these stormwater best management practices could only do so much to protect areas from stormwater. Ironically, their cost-effectiveness may come with a heavy price. The amount of maintenance needed by such systems may discourage some individuals from setting them in place. As such, low impact development experts suggest that the installation of active stormwater collection mechanisms could augment the efficacy of passive rainwater collection systems. These mechanisms include multi-level tanks that could provide extra storage and much needed purification for collected stormwater.