Case Studies Illustrating the Multiple-Use Water Services Options - Rethinking Infrastructure Design for Multi-Use Water Services - page 70

1.3 What Is the Way Forward?

Decentralised Rainwater Management Systems (DRMS) can result in water con-
servation and demand reduction, mitigate the risk of flooding and reduce energy

consumption. They act as a short-term and long-term solution for climate change
adaptation, supplementing the existing urban water infrastructures. The scale of
implementation of such systems varies from small to large and can be customised
according to the site-specific needs.
As of July 2010, there are 659 RHMS in Korea, which are currently being
operated or planned. Most of them are located near Seoul Metropolitan Area,
including 520 facilities in Seoul city and 48 facilities in Gyeonggi-Do. Nearly 30 %
of the total RHMS are installed in housing complexes and 21 % were installed in
schools, while 26 % of them were constructed only for stormwater run-off control
(UN ESCAP 2012 ). The collected rainwater is used for cleaning, irrigation,

re-

flushing, with different usage patterns across types and sites. In
the housing complexes, rainwater stored is almost equally distributed for

fighting and toilet

re-

fighting (36 %), irrigation and gardening (34 %) and cleaning (30 %) purposes. In
schools, gardening is the main use (50 %), followed by cleaning (19 %) and toilet

flushing (16 %), while smaller amounts are allocated to spraying of playgrounds
(11 %) and re ghting (4 %) (UN ESCAP 2012 ).

1.4 What Are the Bene ts of Implementing DRMS?

DRMS use natural water resources to render multiple bene ts in the case of Korea

and Seoul in particular, including: resolve water shortage problems, reduce damage
from

floods, improve river water quality by reducing non-point source pollutants,
preserve groundwater levels, mitigate urban heat island effects, save energy and
reduce emissions, contribute to reghting (from the existing scattered rainwater
tanks), create an eco-friendly environment and improve the quality of life for
citizens by creating better surroundings and environment. They can support the
city s vision towards an eco-friendly Seoul where man, nature and city co-exist,

recovering water environment to pre-urbanisation level.

'

1.5 Benchmarking Example: The Star City Rainwater
Harvesting and Management System

The Star City RHM System (Fig. 1 ), located in Gwangjin-gu (eastern section of
Seoul), has been in operation since 2007 (construction started in October 2003) and is
gaining worldwide attention as a model for futuristic water management and climate
change adaptation system, which supplements the existing centralised water