Application of Low Impact Development Strategy in Sichuan Small Town
Reconstruction and Development Project
Shi Yi1, Jianpeng Zhou2, Ph.D., P.E., Joe Q. Zhao3, Ph.D. ,P. Eng.
1Director, Sichuan Provincial Project Management Office, Chengdu, Sichuan, China [email protected]
2Associate Professor, Department of Civil Engineering, Southern Illinois University Edwardsville, IL, USA [email protected], ESD China Ltd., Shanghai, China [email protected]
Sept. 27, 2011 Philadelphia, USA
2011 Low Impact Development Symposium
Outline
What are the concerns? What are the challenges and opportunities? What were done and learned on LID? What are the LID strategies? What are the obstacles and constraints? What is the outlook for the future?
The Concerns
The Master Equation
Overall Environmental Impact =
Population x resource use x environmental impactperson unit of resource use
2050/2008 factor:1.5 3-5 ??
The Concepts Low Impact Development (LID): land
planning and engineering design approach to managing storm water runoff
LID is considered in the broad context of sustainable developmentEconomic and ecological citiesWater of various types are all relatedWater-energy nexus
Developments and Changes
Rapid economic and social changes in China in last 15 years - over 10% annual economic growth
Rapid urbanization: now 46% living in urban areas, up from 29% in 1995; expected to reach 70% by 2020 – due to reduced control on population mobility and falling demand on farm labor
Challenges and Directions
Significant pressures on expanding public infrastructures, increasing municipal services; developing housing, creating employment etc. in cities
Governments of various levels encourage and focus on developing medium size cities and small towns
Small Towns Development in Sichuan Province, China Sichuan Province◦ 88 mill. population (4th highest in China) in 32
cities and163 counties◦ 62% population living in towns of less than
25,000 vs. national average of 44%◦ Very densely populated, due to 90% of land
hilly or mountainous Small towns (20K-800K people) is critical
due to high population density and low per capita productive land
2008 Earthquake in Sichuan Province
An 8.0 Ms earthquake struck Sichuan on May 12, 2008 Destroyed or severely damaged infrastructures in 39
counties, affected 20 mill. people Sichuan Small Town Reconstruction and Development
Project: grants from the Chinese governments, the World Bank, a French bilateral loan etc. US$850 mill.
The Project is to rehabilitate/rebuild infrastructures: roads, bridges, waterworks, wastewater and stormwater systems
Challenges and Opportunities
The challenges from rapid economic developments and from the earthquake reconstruction also present the opportunities when strategies and technologies for sustainable development including LID can be introduced
The question is: how to do it?
LID History and Experiences
In fact, some LIDs have been applied in China
Examples: ◦ Chengdu, Sichuan Water Park◦ Green roofs
Chengdu Water Park Built in 1998 The river collects
urban runoffs Part of river water is
diverted to the Water Park going through a series of pond units, then is discharged back to the river
Chengdu Water Park To demonstrate a scheme of water quality
improvement - from class IV (recreational use) to Class III (acceptable as water supply sources)
LID Strategies for Small Towns To develop guideline and design standards for
incorporating LID best practice in reconstruction and development
To incorporate LID in planning, design, construction To promote rainwater harvesting and water reuse To consider LID in broad context and link water with
energy To aim for financial sustainability – balancing between
environmental and economic needs
LID Guideline and Design Standards
LID guideline and design standards are not in place, although are under development
To analyze “Singapore ABC Water Guideline”: Active, Beautiful, Clean Waters Design Guidelines by Singapore Public Utilities Board (PUB) - highly urbanized and high density
To conduct a “Comparative Study between China and USA on Sustainable Stormwater Management for Township Development” – what are suitable and practical for use in China?
Example BMPs for LID in Singapore ABC
Swales in parking lots and roadways
Swales to buffer open space from development
Constructed wetlands to buffer open space from development
Cistern to store rainwater for irrigation
Street drains to wetland via swirl separator; trash area drains to sewer via swirl separator
Vegetated roof to reduce runoff
Vegetated slope to reduce erosion and sedimentation
LID in Planning, Design and Construction The Sichuan earthquake reconstruction program is
planned for seven years from 2009 to 2013. The initial phase (2009-2011) was for rapid disaster
relief and placement of affected people Shift in the concepts on earthquake reconstruction
from “rebuild” to “new build”: not to simply rebuild what were destroyed, but to build the infrastructures based on the most current concepts and best practices for sustainable development including LID
The urgent need to catch up with design and construction (some already under way), so LID measures can be incorporated
Rainwater Harvesting and Water Reuse Rapid housing development: water
gardens become a standard component of the commons in newly developed residential communities◦ Mainly use potable water as the
supply to water gardens◦ Often not operated well, due to
costs of potable water◦ To harvest rainwater for water
gardens?
Rainwater Harvesting and Water Reuse Gray water system for water reuse
are required in many newly built residential communities (government policy)◦ Intended for using treated
municipal wastewater◦ Treating wastewater to water
reuse standard costs twice as the set price paid by customers -financially not sustainable
◦ To harvest rainwater for water reuse – need to be planned and designed for and built into community development
Broad LID and Water-Energy Nexus Water of all types are all related ◦ The Water Park example: stormwater management – water quality for
water supply sources
◦ The water garden design: the use of rainwater instead of treated wastewater
Water and energy linkage: may towns in Sichuan are in valleys, water supply sources from mountain, to consider mini-hydro to recover energy from unused water heads
Financially sustainable: solar powered lighting system (much higher cost than a traditional system, who pays?)
Obstacles and Constraints Lack of policy, guideline, and standards - behind
project schedule, need to catch up with the rapid developments (no time to wait!)
Insufficient experiences in planning and design LID is encouraged but not compulsory Competition for land between business
development and environmental use Water pricing on potable water, treated
wastewater, harvested water… Incentive for LID practice: cost-benefit analysis
Outlook for the Future To develop and integrate LID in guidelines and
codes of planning and design To identify suitable LID concepts, measures and
experiences in US for application in China - a collaborative project is underway
To consider ECO2 – Economic and Ecology Cities (World Bank programs)
Welcome your inputs, [email protected]
Thank You!