Environmental problems related to infrastructure development
Infrastructure is essential for increasing economic progress and reducing poverty. The choices made in the type and scale of infrastructure investment also have major implications for environmental sustainability.
New infrastructure typically involves land use change and the selection of the site and its proximity to human settlement will significantly affect its impact. Refurbishment, rebuilding or replacing previous infrastructure may also change the use of the land on which it sits and its impact. he construction and disposal of infrastructure can impact on the condition of the soil structure. For example the use of vehicles and heavy machinery may cause compaction of soils; land clearance may lead to soil erosion; and the infrastructure work may cause soil contamination with toxic materials.
Buildings and hard landscaping reduce the capacity of the land to absorb rainwater and increase run-off, reducing the land’s ability to store water or act as a flood plain and can impact on river flows and the sediment cycle.
Ecology and biodiversity
Infrastructure can significantly impact on the ecology and biodiversity on the chosen site and in surrounding areas. In addition to site based impacts, infrastructure can affect ecology through its impact on water courses (for example from dams) or the air (for example from wind turbines). Many impacts will be local to the site of the infrastructure but in some cases there may be impacts across a much wider area.
Change in land-use as a result of infrastructure development will destroy existing habitats and affect the species that lived there. Degradation of the surrounding environment during construction, operation or decommissioning through noise, vibration and light pollution or waste (e.g. dust created during construction) may also disturb habitats and wildlife and can affect plant and fruit growth. For example, a power station may increase water temperature as a result of discharge of cooling water and this in turn may alter growth, metabolism, feeding habits, reproduction or migration of aquatic species.
The use of land for infrastructure projects may hinder the movement of animals through habitat destruction or fragmentation. This can impact on species population dynamics e.g. distribution and abundance; and for rare species in extreme cases can result in species extinction. For example in Europe increased road infrastructure has been linked with the threat of extinction of hedgehogs.
Water resources and aquatic environment
Infrastructure can impact water resources (including water quality); flood risk; consumption of water during construction and operation; and water embodied in the materials used to build and maintain the infrastructure.
Infrastructure construction and its use may add to increased demand for water and so add to pressure on water supplies in the local area. This may be of particular concern due to growing pressure on the quantity and quality of water supplies as a result of climate change. Pressures from water demand where there is scarcity can also impact communities away from the site of the infrastructure and this can be beyond national borders.
The operation of water management infrastructure over time can lead to wear and tear of the network of pipes and valves and result in water leaks. Burst pipes can disrupt water supply and lead to flooding of areas and properties and also waste a valuable natural resource. Leaking discharge pipes can spill untreated waste water.
Enormous amounts of materials and energy can be used in the construction and operation of an infrastructure project. Construction of infrastructure uses a significant volume of materials derived from natural resources, such as timber, concrete and steel. And rare natural resources are used in the manufacture of equipment. The sourcing, processing, manufacture, distribution, use and disposal of construction materials can have significant local and global environmental impacts.
Many materials used in construction or the operation of infrastructure, such as coal or nuclear power stations, can be from unsustainable sources or damage the environment and create pollution during their extraction, for example stone or sand quarried or timber harvested unsustainably. For power stations, for example, coal mining can release methane, a potent greenhouse gas.
Green house gases emission and air pollution
Energy is consumed and greenhouse gases are emitted during the transport to site of the construction material and the workers; the operation of heavy construction machinery; the operation and maintenance of the infrastructure; treatment of wastewater; and the operation of heavy machinery and the transport of waste material during the demolition of infrastructure.
Transportation of staff and raw materials to and from infrastructure development sites results in emissions to air of carbon dioxide, carbon monoxide, nitrous oxides (NOx), sulphur oxides (SOx), dust, polyaromatic hydrocarbons (PAHs) and particulate matter (PM). These emissions contribute to climate change and have impacts on air quality which can result in both health and environmental impacts. Using materials from local resources and supplies can lower the transportation impacts. In some cases greenhouse gas emissions could be reduced through use of lower carbon means of transport, such as transportation by water.
New infrastructure projects can affect the physical, cultural, social and economic factors in an area. The nature and scale of the impacts on the human environment will be substantially determined by the location of the infrastructure. Maintenance or modernisation of existing infrastructure to extend its operational life can maintain its social or economic benefits.
Displacement of local populations, including indigenous populations, during construction may threaten the sustainability of community structures and cultures. Such displacement can happen in the immediate surrounds or across a wider area, for example if a dam reduces water flow and disrupts community life downstream.
Once built, infrastructure can have negative impacts on the local community. For example, in addition to impacts on ecology and the water environment, a road generates traffic which can be a nuisance and hazard for the local community. New infrastructure development may also lead to reduced access to previously used green infrastructure.