URBAN PLANNING AND DESIGN. DESIGNING WATER SENSITIVE URBAN

DEVELOPMENTS

Presented at the 4th Annual Effluent & Water Management Conference & Exhibition 2014

Jeremiah Atho Ougo

Side drains, mitre drains, cambres

Pedestrian precincts and water

Definitions Urban Design: Urban design is the process of designing and shaping cities, towns and villages. Whereas architecture focuses on individual buildings, urban design address the larger scale of groups of buildings, of streets and public spaces, whole neighborhoods and districts, and entire cities, to make urban areas functional, attractive, and sustainable.

Video link 1 on WSUD https://www.youtube.com/watch?v=wfOqMj-hXVc

WSUD: Water Sensitive Urban Design (short: WSUD) is the interdisciplinary cooperation of water management, urban design and landscape planning. It considers all parts of the urban water cycle and combines the functionality of water management with principles of urban design. WSUD develops integrative strategies for ecological, economical, social, and cultural sustainability (compare fig. 6). The objective of Water Sensitive Urban Design is to combine the demands of sustainable storm water management with the demands of urban planning, and thus bringing the urban water cycle closer to a natural one Water Sensitive Urban Design (WSUD) is about integrating water cycle management into urban planning and design. WSUD looks to manage the impacts of storm water from development. WSUD works at all levels – at the lot level, street and precinct level, as well as regional scales – with the aim of protecting and improving waterway health by mimicking the natural water cycle as closely as possible.

Basic Principles of WSUD • Protecting waterways: This principle intends to protect

waterways within urban developments so that they can remain valuable community assets that enhance liveability and support the ecosystem that rely on them.

• Managing storm water in the landscape: This principle intends to manage storm water in the landscape rather than drain it all to waterways. This reduces the volume and frequency of storm water drained and increases the quality before storm water reaches waterways.

• Adding multiple benefits while minimizing development costs: This principle provides for a range of benefits such as alternate supply, improved amenity and safety, and contribute to enhanced liveability by enhancing natural features such as rivers and lakes. WSUD minimizes the drainage infrastructure development costs by reducing pipe sizes and potentially replacing other large scale reticulated water systems with local solutions.

General application of WSUD Grassed or landscaped swales (A swale is a low tract of land, especially one that is moist or marshy. The term can refer to a natural landscape feature or a human-created one. Artificial swales are often designed to manage water runoff, filter pollutants, and increase rainwater infiltration.) Bio swales are linear, vegetated ditches which allow for the collection, conveyance, filtration and infiltration of storm water. The can also be referred to as "grass swales," "vegetated swales," or "filter strips." Storm water is first collected in the trench, and if the water accumulates faster than it is carried away, then the water will pool. The reason why water accumulates in a bio swale and not in a gutter is that the vegetation adds roughness to the channel, greatly reducing the velocity. This effect delays the time of peak run off. The vegetation does more than reduce the velocity of the water, as plants filter suspended sediments from the water passing through them. While the plants remove these large particles, microbes in the soil digest organic nutrients which in high concentrations can be considered pollutants.

Artificial bio-swale

Walkways and water

General application of WSUD Permaculture is a philosophy of working with, rather than against nature; of protracted and thoughtful observation rather than protracted and thoughtless labor; and of looking at plants and animals in all their functions, rather than treating any area as a single product system. —Bill Mollison. Infiltration trenches and bio-retention systems Gross pollutant traps, wetlands and sediment ponds Rainwater tanks – stormwater harvesting and reuse Grey water harvesting and reuse Rain gardens, rooftop greening and urban forests Porous pavements Aquifer recharge and reuse

General application of WSUD WSUD applications are flexible and can be implemented across different types of developments and at different scales, from a standard residential extension or road renewal through to a new subdivision. Good planning and design will ensure successful outcomes.

Video link 2 https://www.youtube.com/watch?v=LMq6FYiF1mo

Global examples: The Rotterdam Waterplan 2

Rotterdam is situated 2 meters below sea level, The city is surrounded by dykes and has a complex pumping system that protects the city from flooding. It became increasingly clear that Rotterdam would be seriously affected by climate change (higher water level due to rising sea levels; flooding caused by increased rainfall) In response, Rotterdam developed Waterplan 2, a comprehensive joint approach to spatial planning and water management

The Rotterdam Waterplan 2 The spatial Plan seeks to do the following: Protection: Protect Rotterdam against flooding, both inside and outside the dykes. Clean Water: Ensure water quality required by the European framework directive on water to Improve the cities’ amenity. Attractive City: Integrate urban planning with water management to solve water problems and enhance the city's attractiveness as a place to live, work and relax. Sewers: Reorganize storm water runoff via decentralized innovative solutions that perfectly match the specific area.

• 4.2 Also implemented in Lodz, Poland,: • 4.3 The Blue-Green Network and the Oregon USA

Examples in Kenya UN-Gigiri NOF NOF is located within the 140-acre UN compound in Gigiri. Rainwater harvesting, waste water recycling and wetlands maintenance where rainwater is collected from the roofs to feed the fountains and ponds at the four entrances. Sewage is treated in a state-of-the-art aeration system and recycled to irrigate the beautifully landscaped compound. Water saving lavatories, a central atrium and lightwells in every office zone, contributes to sustainability. Around 7.5 million litres of rainwater could be harvested from the roof of the new building in an average rainfall year. Rainwater and recycled water meets all the irrigation needs of the new building compound Dual flush lavatories reduce water consumption by between 40 and 60 per cent

Muthaiga Residential Zone New or existing roads in large or small development areas; (Insert photo of Muthaiga road with pedestrian walkways, storm and waste water drainage channels along a camber with green grass vegetation cover. Also include Tchui lane access road in Muthaiga.) Drainage systems being upgraded New residential developments – detached housing, medium density or integrated housing Existing residential developments – redevelopment and infill areas Commercial or industrial properties and estates Carparks, driveways and access routes

Video link 3 on https://www.youtube.com/watch?v=5v53Dxmc5Q0

Thank You!