Description of individual activities

Project Summary

Black, Blue & Green – Integrated infrastructure planning as key to sustainable urban water systems (2BG) explores the possibility for a paradigm shift within urban water systems, a shift that focuses on citizens’ life quality and long-term functionality of applied management concepts.

Taking stormwater as point of departure, the 2BG key-challenges are to analyse

1) potential for massive infiltration to avoid sewer overflow, and to recharge local streams and aquifers,

2) methods for water quality control to avoid pollution of receiving environments and improve re-use opportunities, and

3) options for inclusion of technical water systems as assets in urban life.

(Foto "Gennemsivelig befæstelse, Leidsche Rijn" venligst udlånt af Marina B. Jensen)

Through four PhD-studies and one PostDoc 2BG outputs will include: a model for simulating urban water flows in response to increased infiltration, IT-tools for city-level dimensioning of stormwater infiltration, evaluation of catchment policies and end-of-pipe options for control of water quality, and support-tools for integrating urban water systems in the green infrastructure.

Additional research will result in evaluation of urban water planning processes in Danish municipalities, and identification of political-economical drivers and barriers for sustainable water management.

Events to enhance the transfer of knowledge between urban planners, engineers and landscape architects will be arranged.

The 2BG Project Idea

Research idea and plan

The sewers of the cities have played an important role in ensuring a hygienic and safe urban environment during the last 150 years. However, it is increasingly recognized that continuous extension of the sewer systems’ capacity is not an appropriate answer to the challenges we are facing today, whether it be in developed or developing countries. There are basically three problems:

1)      Sewers are sensitive to climate change and continuous urban growth

2)      With sewer systems valuable freshwater is discharged rather than recharged

3)      Sewer solutions neglect aesthetical and socio-cultural assets of water.

Thunderstorms already cause episodes of sewer overflow, flooded basements and roads, and inundation of whole cities. With the foreseen climate changes this will become worse. Growing cities, which is a worldwide trend driven by rural-urban migration, and expanding pavements within existing urban areas magnify this problem by increasing the amount of storm and wastewater discharged into the central sewer systems.

When employing centralized sewer systems the options for recharging the wastewater to supply purposes, e.g. reuse or groundwater production, are limited. Furthermore, leaking pipe systems give rise to uncontrolled groundwater contamination and drainage of groundwater resources.

In affluent urban societies the additional assets of water, i.e. as recreational and aesthetical elements in the urban landscape, are in increasing demand. Demands that can be serviced if underground sewer-based discharge systems are replaced with decentralized and visible solutions based on retention and infiltration – to the benefit of both citizens and the environment.

The idea of the 2BG initiative is to establish a consortium that has the capacity to tackle the complexity of existing urban water systems and their many stakeholders, and to suggest improved systems for the future, i.e. systems that

1)      are adapted to more frequent thunderstorms and increasing urbanisation

2)      provide options for linking discharge systems to water production and supply systems

3)      prepare for enjoying the ‘soft’ sides of water in the city.

Such solutions are in accordance with the Rio declaration Agenda 21 that focuses on long term sustainability of urban development.

The suggested consortium consists of an interdisciplinary partnership between universities, private companies, end-users and professional communicators; a consortium that represents the necessary key-competencies for realizing the 2BG idea.

Research hypothesis

The overall hypothesis is that a paradigm shift is needed for urban water systems to comply with the three requirements listed above. It is assumed that the shift in paradigm will involve 

1)   centralized discharge systems being replaced or complemented by decentralized discharge systems based on local treatment, reuse, retention and infiltration

2)   the planning and design of discharge systems being coordinated with and – whenever optimal – linked to the freshwater production and supply systems

3)   the planning and design of discharge systems being an integrated part of green infrastructure planning and design – and vice-versa.

Accordingly, conceptual models and supportive tools will be developed to create better interfaces between hydrological engineers, infrastructure designers, urban planners, landscape architects and decision makers. It is further asserted that capacity building within the Danish water resource base regarding such a new paradigm will rapidly pay off in terms of increased international market shares.

Delineation of research and overall approach

The research hypothesis will be approached through eight activities, A1-A8 (see Fig. B1 in App. b). A1 will develop and apply models for quantification of urban water systems on the urban catchments level, while activity A2 characterises water quality and pollution risks. A3 develops models for design, documentation and evaluation of modern, small-scale urban water system components. A3 receives input from and interacts with A1 and A2, as well as A4, which explores options for creation of decentralized systems for safe water reuse and recycling. Together A1-A4 provide a characterisation of flows and water quality through the urban system and develop options for their sustainable management. From an urban design point of view it is important to understand how urban form and functions affect the hydrological system, and which techniques can be adopted for site adapted solutions at city and site levels. This is the task of A5, which will provide information on the hydrological performance of urban green space for A1-A3 and in turn will receive information on water flows and quality for calibration of GIS and CAD based models that will be linked to A3 to support communication between engineers and urban planners. A6 is concerned with developing the knowledge and methods required to make the complex process of planning for sustainable water management smooth. The identified potentials and constraints will be used to tailor methods and tools developed in other activities. A7 focuses on the decision makers by assessing the economic aspects of different urban water system options, including cost-benefit analysis of directly as well as indirectly affected values. Finally, A8 creates the interface for internal communication between the project’s members and stakeholders, and external exchange and transfer of knowledge (T-o-K) with the Danish water resource base. The case studies, which are common for all research activities, will characterise real world problems, information needs, data collection and testing of models, and will be used to demonstrate new knowledge and tools to the wider community. For testing of international T-o-K developed in A8 a case-study in a country with rapidly developing economy will be set-up based on contacts within the consortium.

Kort beskrivelse af projektet på dansk

Livskvalitet for byboere kan kun opnås gennem et sundt og bæredygtigt bymiljø.

Det overordnede formål med 2BG projektet er at bidrage til en global bæredygtig udvikling ved at anvise nye måder, som byer kan omgås med vand på. Ambitionen er at igangsætte en proces bort fra nutidens ”forbrug og bortled” mod en integreret tilgang baseret på forståelse for vandets kredsløb og samhørighed med de grønne områder og byernes infrastruktur, hvor der som en naturlig del også lægges vægt på økonomi og organisationsformer samt på vandets æstetiske og socio-kulturelle værdier.

Projektet sigter på at udvikle koncepter, metoder og værktøjer, som kan stimulere brugen af bæredygtige løsninger. Løsninger, der kan imødekomme klimaforandringer og stadigt større byer gennem lokal nedsivning og genanvendelse af vand.

Modeller til kvantificering af hele det urbane vandkredsløb, samt til design af lokale 2BG løsninger, vil blive udviklet. Risici forbundet med vandets indhold af sundhedsskadelige og miljøfarlige stoffer vil blive undersøgt, og muligheder for kildekontrol og rensning vil blive udviklet. GIS baserede IT-værktøjer vil blive udviklet for at understøtte samarbejde mellem byplanlæggere, ingeniører og landskabsarkitekter, og desuden vil forskellige organisationsformer og brugen af værktøjer til økonomiske analyser til støtte for beslutningsprocessen blive belyst. Resultaternes anvendelighed vil blive vurderet ved hjælp af gennemgående case studier.

Endelig sigter projektet på at gøre resultaterne til en integreret del af den danske videnbase. Nye principper for erfaringsudveksling og videnoverførsel vil blive udviklet og afprøvet i sammenhæng med pilot-cases med sigte på både det nationale marked og hurtigt voksende byområder på det globale marked.