Magok District, Gangseo-gu, is about 16 times the size of Yeouido Park with the total surface area of 3,665,000㎡. This last remaining piece of large-scale undeveloped land in Seoul is being developed as a leading water circulation city.
Previously, simple improvements were made in the district such as replacing worn-out pavement and parking lots with permeable blocks. However, since the need for rainwater circulation and reuse has become an even more pressing issue, development of Magok District is now focusing more heavily on incorporating facilities that allow for the full circulation of rainwater.
This is the first time infrastructure, such as sidewalks and roads, as well as all facilities including apartment buildings and parks will have been built with rainwater management facilities. Seoul officials hope that Magok District will become a representative model of a water circulation eco-city in Seoul.
According to an analysis conducted by the city, by implementing these changes, frequency flood discharge will be reduced by approximately 2% over a 30-year period. Furthermore, water quality will be improved as a result of an increase in groundwater, and a reduction of nonpoint source pollution. The infrastructures are also expected to reduce urban heat islands by delaying runoff and reduce the amount of waste water by recycling water resources.
District-wide developments, already underway, will focus on two aspects: 1) the expansion of rainwater management facilities that improve rainwater permeability, and 2) the reuse of waste water.
<Installation of Permeable Pavement and Roadside Infiltration Inlets , and Elimination of Roadside Boundary Stones>
To reduce runoff and allow rainwater to be naturally absorbed into the subsoil, a total of 650,569㎡ of sidewalk will be paved with permeable blocks. Infiltration inlets will also be installed on the side of roads= and paved with asphalt to withstand the weight of passing automobiles.
Boundary stones along planting strips will be removed for better inflow of rainwater, and the planting strips themselves will be constructed with a concave slope to improve their rainwater infiltration capabilities. In addition, rainwater retention and infiltration facilities will be expanded to collect as much rainwater as possible before the water flows into the sewage system.
<Construction of Rain Gardens in Parks and Green Areas to Install Retention Facilities and Water Purifying Plants>
In parks and green areas, artificial installations will be minimized, and rainwater management facilities that utilize the maximum amount of natural greens will be installed.
To induce natural infiltration of rainwater through geographic features, concave and tiered landscape features will be utilized, and water purifying plants such as reeds and cattails will be planted in rain gardens in parks and green areas to collect and purify rainwater.
Natural infiltration waterways, using grass and gravel, will be installed in parks to channel the flow of rainwater. Infiltration tanks will be placed at regular intervals to increase infiltration in soil.
<Reduction of Urban Heat Islands through Greening of Buildings, such as Apartments, Houses, and Other Buildings, and Installation of Water Tanks to Reuse Rainwater>
The rainwater retention capacity of apartments, houses, and other building will be expanded through the greening of rooftops and the installation of rainwater tanks. In particular, over 60% of rooftop surfaces on private buildings will be strongly encouraged to use greening techniques, which will delay rainwater runoff and reduce the urban heat island effect.
Towards this same end, rainwater from rooftop catchments, excluding green spaces, will be collected in rainwater tanks for use in landscape irrigation; excess rainwater will be allowed to filter back into the soil
<Reuse Reclaimed Water for Landscape Irrigation and other Purposes through Advanced Treatment of Sewage and Groundwater Discharged from Subway Lines>
Seoul will also promote ways to reuse treated waste water discharged from the Seonam Sewage Treatment Center and groundwater discharged from Seoul Subway Line 5 and the Airport Railroad.
First, the city plans to reuse waste water treated at the Seonam Sewage Treatment Center that had previously been disposed. After undergoing advanced treatment, the wastewater will be used for landscape irrigation in Magok District and cleaning restrooms and roads.
Recycled water will be supplied in Magok District in stages starting from June 2016.s. Using recycled water in the private sector for cleaning restrooms (etc.) costs approximately KRW 450 per ton, allowing for a savings of KRW 400 (per ton). Citing these savings, the city will actively encourage the use of recycled water.
Moreover, groundwater discharged from nearby Subway Line 5 and the Airport Railroad (689㎥/day) will be reused to maintain ponds in parks within the district.
Current Status of the Magok Urban Development Project
○ Project Overview
– Area: 3,665,000㎡ (Magok and Gayang-dong area in Gangseo-gu)
– Project Duration: Dec 2007-Dec 2014
– Housing Complex Development: construction of key infrastructures, including water supply and drainage, roads, etc. (in progress: approx. 66% complete)
– Land Supply: currently parceling out industrial complexes, commercial and industrial properties
– Apartment Complexes: 16 complexes, 12,015 households
Phase 1: 9 complexes, 6,730 households; construction begun in Sep 2011; in operation starting May 2014
Phase 2: 7 complexes, 5,285 households; construction begun in Dec 2013; in operations starting June 2016