The growths of metropolitan regions in the twentieth century, both the number and populations of large metropolitan regions, have increased dramatically during the last century. Those with more than one million people, for instance, grew fourfold between 1950 and 2000 to number nearly four hundred, and now accommodate over a billion people, or one in five of the world’s population (United Nations, 1995). They are also home to a host of environmental, social, political and administrative problems (World Commission on Development, 1987). In both the developed and developing worlds, tides of new residents drawn from regional hinterlands and international migration are rapidly swelling the populations of these metropolitan regions. At the same time, their physical growth is being accelerated by new and established households moving out to the fringes in search of space and amenity. As a consequence, metropolitan regions are experiencing, in the prophetic words of Colin Clark (1970), “simultaneous processes of macro concentration and micro dispersion”. Later work of Newman and Ken worthy (1989) on comparative international metropolitan 3 densities has confirmed this. These metropolitan regions not only fail to manage their own problems of growth, congestion, pollution and conflict, but also exert increasing dominance over the economic and political lives of the surrounding regions and nations.

Defining Metropolitan Regions
A metropolis is a big city, in most cases with over half a million inhabitants in the city proper, and with a population of at least one million living in its urban agglomeration. Big cities belonging to a larger urban agglomeration, but which are not the core of that agglomeration, are not generally considered a metropolis but a part of it. A metropolis is usually a significant economical, political and cultural center for some country or region, and an important hub for regional or international connections and communications
A metropolitan area usually combines an agglomeration (the contiguous built-up area) with peripheral zones not themselves necessarily urban in character, but closely bound to the center by employment or commerce. These zones are also sometimes known as a commuter belt, and may extend way beyond the urban periphery depending on the definition used.
The Nairobi Metropolitan region depicts these characteristics and can easily be defined by the core Nairobi city and the surrounding fourteen local authorities within the greater Kiambu, Thika, Machakos and Kajiado districts.Metropolitan boundary definition has the following Criteria;
Administrative
The metropolitan regions are defined based on the legal or administrative statutes of municipalities. This corresponds to the city as an instrument used by the state to structure, manage, plan and develop a country.
The defined area is a forum for the interaction of local actors (governance).

Morphological
This is based on the extent of observed trends, continuity of built-up area, the number of inhabitants, and proportion of the Municipal areas covered by urban settlements. On this basis, the metropolitan area is largely urban in character.

Functional
This is based on interactions between the core area defined according to the morphological criteria above, as well as the surrounding territories. Daily commuting flows are central to this as they reflect the existence of a common labor market.
This approach takes the city as an economic and social entity.

Definitions:

Development in the simplest of terms is the gradual progression from a lower state to a higher state. It is an improvement in the way of being of a state.

Planning in this context is the organized anticipation of future events and being ready for them before they happen.
In terms of the built environment, it is the organization of land uses in space.

Development planning therefore can be said to be the organization of activities in space that will lead to the improvement in the livelihoods of a people. Further to this is the concept of sustainable development which is the ability and capacity of a people to meet their needs in the present while at the same time preserving the ability and capacity of future generations to meet their own needs.

Metropolitan regions have within themselves challenges that affect their management and effective service delivery to their residents. These include but not limited to:

Changing External Conditions
Recent educational development in Africa has been supported by the so called economic “miracle” in the region. There seems to have been a strong correlation between educational and economic development. High performing African economies, however, appears to have structural problems in their economies. These structural problems induced economic crisis through massive current account deficit and uncertainty in the financial system since mid 1990's. As a result of the crisis, most African countries, and especially the hardest-hit countries, experienced dramatic drops in GDP growth. The social impacts of the crisis are transmitted by increased under- and unemployment, reduced income, and increased prices and generally declining quality of life for residents. As a result, the metropolitan economy is unable to provide basic facilities and services.

Transport and Traffic Management
Traffic management dominates Metropolitan development challenges. Simply put, traffic woes in Metro regions stem primarily from an insufficient road system, the rapid increase in use of private transportation, the lack of quality public transportation services, poor enforcement of traffic regulations and lack of discipline on the part of both motorists and pedestrians. In addition, there is a problem of overlapping of functions, mandates and duplication of services in view of the multiplicity of players involved in transport and traffic management in many a metropolis (Nairobi Metro-urban transportation study) suffice to say that successful metropolitan regions are those that have given preference to public rather than private transport systems.

Solid Waste Management
Solid waste Management remains a major challenge in many aspects. Historically, the metropolitan regions are a conglomeration of independent local authorities each with individual service delivery mechanisms. As a result, capacity to manage solid waste is greatly affected by parameters of economies of scale. It is now dawning to the powers that be that an integrated metro-wide solid waste management plan must be put in place. After all, generation of waste and disposal cannot be restricted to administrative boundaries.

Water resources management
Freshwater is essential for human survival. It has contributed significantly to the attainment of development goals in various sectors of the plans of many different countries. Over the years, water demands for domestic and municipal use, for agricultural purposes and for industrial processes have been steadily increasing. However, the quantities of water that any country can economically develop on a long-term basis unfortunately continue to remain limited. Moreover, the quality of the available water resources is increasingly degraded in many areas due to the large volume of industrial and other wastes from human activities being disposed of to the environment without much treatment. Under these circumstances, water management practices have to be significantly more efficient in order to ensure a continued adequate water supply for present and future needs. This certainly is a complex challenge for water management professionals in the 21st century. The recent developments in the City of Nairobi where water rationing is being effected is proof enough of the enormous challenge metropolises’ managers are faced with in terms of provision of water for all their residents.

Define effective boundaries
In searching for appropriate ways to define effective boundaries, administrators have frequently found themselves overtaken by the expansive effects of improved communication and increased levels of interaction. The most recent attempts to create an effective system of regional governance by integrating all the 15 local authorities making up Nairobi Metropolis into a single functional planning and development unit with a population of over four million has incurred some setbacks. This is evident that boundary changes and administrative mergers provide no lasting solution to the problems of coordinated administration and planning for metropolitan regions. As a result of such difficulties, many large and populous metropolitan areas lack effective and integrated planning and administration (Gunlicks, 1981, Self, 1982).
A number of metropolitan regions have opted to build consensus amongst individual entities based on a common vision. Metro Vancouver, Canada has successfully overcome this challenge.

Inadequate infrastructure and Utilities
The Metropolitan regions are characterized by poor service connections, poor network accessibility, inadequate capital investments and in adequate operations and maintenance inter-lia other factors.
All the above has accumulated to compromised productivity of firms and individuals, high cost of infrastructure and utilities, poor quality of life and environmental pollution.

Poor Quality of Life
Some Metropolitan regions experience poor quality of life that is described by poor access to medical services, poor quality housing, inadequate access to housing, poor access to education services and ineffective spatial planning regime.
The effects of this include; negative ethnicity, social and cultural segregation, poverty, high income inequalities, inadequate public spaces, poor safety and security, and proliferation of slums.
The lack of o common vision by metro residents denies them a chance to integrate their aspirations. The metro-region thus becomes the hotspot of civil unrest which easily transmits to the rest of the country. The events of 2007/2008 in Kenya are evident.
Ineffective Metropolitan Governance
Most of the metropolitan regions have in adequate capacity in governance institutions; there is poor client focus and uncoordinated efforts of various institutions. The effects of this are adverse in that there is poor resource mobilization, curtailed potential for innovations in resource mobilization efforts and mistrust of governance institutions by citizens.

Conclusion and Way Forward
A time comes when the metropolitan challenges outgrow the local administration which forces the central government to intervene not only to boost resources but more so to enhance their management. This is in realization that most of them account for over 50% of the national GDP. The ministry of Nairobi Metropolitan Development is the precursor to this and the normal metro challenges are evident and can only be addressed through a common vision by the residents for the common good.

References:
1. Metro 2030 strategy
2. Metropolitan Planning (Brendan Gleeson, Toni Darbas, Laurel Johnson and Suzanne Lawson)
3. Governance and Urban Development: Case Study of Metro Manila Rosario G. Manasan and Ruben G. Mercado
4. Urban Growth Management for Mobility: Christopher Zegras & Ralph Gakenheimer
5. National sustainable development strategies: features, challenges, and reflexivity*,James Meadowcroft Carleton University
6. Challenges and Perspectives on Metropolitan Governance in Athens, P. Getimis/ N.-K. Hlepas
7. The Public Economy of Metropolitan Areas, Chicago, Markham. Bish R, 1971
8. Analysis of Urban Development, Proceedings of Tewkesbury Symposium, Melbourne, Department of Civil  Engineering University of Melbourne, Clark N. (Ed) 1970
9. Metropolitan Service District of Greater Portland (Metro Portland) 1990   The Metropolitan Service District, 600 NE Grand Ave, Author, Portland