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 shiyisccd@gmail.com

2Associate Professor, Department of Civil Engineering, Southern Illinois University Edwardsville, IL, USA jzhou@siue.edu3Director, ESD China Ltd., Shanghai, China joeqhzhao@gmail.com

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

Sichuan Province, China

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)

Chengdu Water Park Giving green space and park area back to

residents

Green roofs in Chengdu, Sichuan

Business centers, hospital, residential

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

Example BMP for LID Eco-retaining wall design

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, jzhou@siue.edu

Thank You!