Sponge City – Rainwater Harvesting System

01 ：Definition

02 ：System Classification

03 ：Advantage

04 ：Concept traveling

Definition

The U.S. Environmental Protection Agency (EPA) defines a rainwater harvesting system as "a technical system that collects rainwater from impervious surfaces and stores it for later use."The entire process consists of five steps:rainwater collection via rainwater pipes → pollutant interception and initial diversion → rainwater storage in PP rainwater harvesting modules → filtration and disinfection → purification and reuse.

System ClassificationAccording to different rainwater sources, they can be roughly divided into two categories:

1.Roof Rainwater:

2.It is relatively clean with few impurities, sediments and other pollutants. After initial rainwater diversion and simple filtration, it can be directly discharged into the water storage system for further treatment.

3.Ground Rainwater:

Contains more impurities and complex pollutants.After initial rainwater diversion and rough filtration, sedimentation is also required before being discharged into the storage system.

Advantage

1.Effectively control peak surface runoff and reduce pollutants, alleviating flood control pressure on urban drainage networks. Rainwater harvesting and reuse can also recharge groundwater resources, regulate the regional microclimate, and improve the living environment of urban residents.

2. Compared with other water supply systems, it features lower cost, ease of use and simple household maintenance.

3. Effectively reduce municipal water supply and tap water costs; lower operation and maintenance costs of drainage networks caused by excessive runoff; cut water pollution control expenses; reduce flood losses and increase relevant national fiscal revenue, thus achieving considerable economic benefits.

4. Effectively raise residents’ awareness of water conservation and rainwater resource utilization; reduce the risk of urban waterlogging and facilitate residents’ travel and daily life.

Concept Traveling 

Urban Rainwater Harvesting System:Among all urban rainwater management and utilization measures, the Rainwater Harvesting System (RWHS) is one of the key technologies to address community water shortages and effectively reduce surface runoff.

In urban areas, RWHS collects, stores and treats rainwater from roofs, terraces, courtyards and other impervious building surfaces for uses such as toilet flushing and garden irrigation. It aims to reduce the consumption of drinking water supplied by municipal water networks.