2022/07/13      Author: HDD

Recently, the ‘Beautiful Home’ project for Haiying Community in Pengpu Town, Shanghai (a Sponge City pilot project), designed by Shanghai Huadu Architecture and Urban Design Group (HDD), has been selected as one of the ‘Best Environmental Upgrade Projects’ in the 2nd Shanghai Housing Renovation Design Award in the specialized design for existing projects category, issued by the Shanghai Exploration and Design Trade Association (SEDTA).

Honorary Credential

The award is co-organized by the Shanghai Municipal Housing Repair Affairs Center, SEDTA, the Shanghai Housing Renovation Trade Association, and the Shanghai Real-Estate Science Research Institute, under the supervision of the Shanghai Municipal Management Commission of Housing and Urban-Rural Development, and the Shanghai Municipal Bureau of Housing Security and Management. Since the selection began on July 1st 2021, nearly 100 design firms, universities and individuals have registered and submitted 118 entries for the award. After several rounds of review by the organizing committee and the panel of experts, as well as an online open voting, 45 winning projects were finally announced.

Project Overview

Project Background

Haiying Community in Pengpu Town is one of the first pilot areas for the ‘Sponge City’ renovation scheme in Jing'an District, Shanghai. It is forward-thinking in terms of its sponge city design concept, ecological strategies and participative community renovation. The goals of the project include rainwater harvest and reuse, ecological and environmental improvement, and providing better habitats for wildlife. After the renovation, for Haiying Community, its volume capture ratio of a one-in-5-year rainfall (over a 24-hour period) reaches 100%, the runoff ratio (annual) reaches 85%, with a suspended-solids removal (annual) of 70%.

Site Condition

Haiying Community was built during the 1970s and 1980s. It is located in Lane 3300, Changzhong Road, Pengpu Town of Jing'an District, covering an area of 72,000 square meters. Over the years, as it lies in a relatively low point in the terrain, and since it lacks an efficient municipal drainage system, waterlogging has occurred frequently, affecting the daily life of local residents.

Context

Ⅰ. Site Analysis

The project proposes a cooperation between designers, engineers (specialised in sponge city), the neighbourhood committee and resident representatives, under Shanghai’s ‘Community Planner System’. The idea of participatory planning was introduced to bring together the practice of community renovation, sponge city ecological design, environmental upgrade, and most importantly, encouraging community self-governance to create a more bottom-up model for sponge city projects. The design team has organised multiple site visits and workshops with the neighbourhood committee, the property management committee, the homeowners' association and resident representatives to listened to their needs, through which two major problems have been identified: 1. inadequate drainage and stagnant water caused by low permeability of the ground surface; 2. low-quality public space with insufficient types of drainage facilities, vegetation, and spatial diversity.

Problems Raised in Workshops

Participatory Design Process

Ⅱ. Computer-Aided Analysis

With the help of GIS, the designers carried out elevation analysis, watershed analysis and solar analysis to zone out potential areas with standing water problems, based on which CCTV records over different time were studied to identify 7 critical areas with frequent waterlogging issues. For different types of rainwater problems in these areas, various types of sponge city infrastructure have been proposed.

Areas with Standing Water Problems

Design Strategies

With safety and liveability being the major demands of the community, two strategies, ‘from needs to harvest design’ and ‘from needs to spatial design’ were proposed to compose a multi-functional design through a multi-party participative process towards the above-mentioned long-standing problems.

Two Main Design Strategies

Strategy Ⅰ:  From needs to harvest design – towards a multi-functional and phased sponge harvest system

Through on-site survey and stormwater modelling analysis, sectional, micro adjustment of the site was made to form catchment zones basing on existing building layout and public spaces. Three types of sponge modules – I (Infiltration), C (Cleansing) and S (Storage) were designed, which vary in the parameters of volume capture ratio, runoff ratio, cost, and landscape value, in order to solve the problems of low permeability of ground surface, insufficient drainage network and inadequate vegetation in the old community. A hierarchical, nodal sponge rainwater harvest plan was designed in response to existing site conditions, maximising drainage efficiency through shortening flow distance. The system was designed for future adaptation where an underground pipeline network will be built to harvest and reuse rainwater within the community.

ICS Sponge Modules for Rainwater Harvesting

Strategy Ⅱ: From needs to spatial design – towards technical, ecological, planning-oriented and multi-participative space making

With solving waterlogging problems and improving public spaces as the priority, the design has distinguished five catchment areas and two ecological parking areas where different types of sponge modules were chosen and put together as a unit according to the characteristic and demand of each site. Through underground pipelines, the five catchment units are interconnected to form an integrated rainwater harvest system that is hierarchical and could be constructed and upgraded through various phases.

Sponge Rainwater Harvesting System, Units and Modules

Features

To create diversified landscape nodes within the community, a general layout of ‘one belt and five gardens’ was proposed to address existing site conditions. A 600-meter-long promenade connecting five programme areas – the Harmony Garden for exhibitions and all-age activities, the Rainbow Garden for children's amusement and education, the Fitness Garden for workouts, the Lighthouse Garden for elderly to daily hangout, and the Purification Garden for ecological education – so as to meet social needs of people of different ages and offer vibrant community life.

The Plan of ‘One Belt and Five Gardens’

The hierarchical, nodal and phased rainwater harvesting system is designed to effectively collect, convey, store, and purify rainwater in the community. Through rational, detailed section designs where elevation is modified and ground permeability is improved, as well as a plan-based layout design of drainage facilities, the rainwater runoff within the site is guided into the ecological stormwater management facilities unobstructed. When the rainwater tanks are full, water overflows into the municipal drainage system through overflow ports.

Layout of ICS Sponge Facilities

Ⅰ. I – High Infiltration Modules

I – High Infiltration Modules – are mainly composed of highly permeable brick pavers and coloured pervious concrete. They are used in the promenade, parking areas, the Fitness Garden, the Rainbow Garden and the Lighthouse Garden. The pavement increases permeability of the ground surface and accelerate stormwater infiltration during heavy rains.

Fitness Garden with Highly Permeable I Modules

Fitness Garden after Renovation

Pervious Concrete Belt Permeability Test

Engineer Explaining the Mechanism of the Rainwater Management System

Ⅱ. C – Multi-Level Cleansing Modules

C – Multi-Level Cleansing Modules – are composed of rain garden, bioretention area, natural filter plants, infiltration pond, permeable pavement and drainage pipelines. It is mainly used in the Harmony Garden, the Purification Garden and large public spaces where there are existing green spaces and corridors that could be used for rainwater storage and purification.

Harmony Garden Multi-Level Cleansing Modules

Harmony Garden after Renovation

Cross-SectionModel of Multi-Level Cleansing Module

A Small Sunken Garden

Ⅲ. S – Highly Flexible Storage Modules

S – Highly Flexible Storage Modules – consist of overflow ports, rainwater wells, underground rainwater tanks, storage tanks, pumping stations, circulation pipes and high pressure water mist nozzles. They effectively store rainwater for greenery maintenance, and can flexibly convey overflow rainwater into the municipal drainage network during rainy seasons, so as to utilise rainwater and reduce emission.

Purification Garden Highly Flexible Storage Modules

Sand Pool Filter in the Purification Garden after Renovation

Renovation of Relaxing Outdoor Space

Highly Permeable Footpath

Infiltration Pond in the Purification Garden

Pioneering Role

With a cost in line with normal renovation projects, the design uses ecological rainwater management facilities to improve the community’s ability to prevent waterlogging as well as its landscape environment. Practicing the PPP (planning, participating, put-into-effect) community renovation model, the project has received wide attention upon its completion. It is equally praised by district and municipal governors and local residents, as well as media such as the Shanghai Media Group News and General Channel and Xinmin Evening News. Through finishing this pilot project and setting up an innovative framework for sponge city renovation design, the long-term goal of the design team was to provide experience and reference for future sponge city community renovation projects, within a larger context of ecological urban regeneration and urban governance.

Project Receives Public Attention