Sudden or progressive changes in the local environment often adversely affect the lives or living conditions of people. These people may then be forced to leave their homes. When environmental degradation occurs or natural hazards rapidly impact vulnerable areas, people may be forced to move. Relocation areas require proper infrastructure. The new infrastructure should be built to be resilient and strong enough to endure the impact of future natural or manmade hazards.

Marginalised people are often impacted by construction activities, sometimes forcing them to relocate without any consultation. Vulnerable or minority people should always be consulted and their needs accommodated within the response design.

Air pollution
Soil pollution
Water pollution
Deforestation
Desertification
Loss of biodiversity and ecosystems
Natural Resource Depletion
Soil erosion

1. Soil erosion, and water and soil contamination due to uncontrolled water flow

2. Soil erosion and soil and water pollution caused by the construction of channels for the conveyance of stormwater flows

3. Reduction in rainwater infiltration and groundwater recharge due to over compaction of site soil

4. Poor drainage can lead to erosion, flooding, potholes, and disease spread

5. Poorly managed surface water, greywater, or overflowing sewage can all contaminate water sources and spread disease

6. Use of earth drainage channels can lead to soil loss

1. Poorly managed construction activities can lead to soil erosion, and water and soil contamination due to uncontrolled water flow.

2. Construction of channels for conveyance of stormwater flows can lead to excessive soil erosion and soil and water pollution

3. Construction activities, if not planned well, can over compact soil, reducing rainwater infiltration and groundwater recharge

4. Poor drainage can lead to water accumulation, causing erosion and sedimentation while also creating potholes (a vector hosting concern) and impeding access. Uncontrolled water can also damage other infrastructure, dwellings, and belongings, limit livelihood opportunities, and cause stress. Poor drainage also provides conditions for vector breeding.

5. Poorly managed surface water run-off, household greywater, or flooding septic tanks can all lead to long-term contamination of water sources or the ground near the site, and also act as a host for vector-borne diseases.

6. Use of open earth drainage channels can lead to soil erosion, particularly in areas with steep slopes; or the formation of stagnant water pools in flat grounds.

1. Poorly managed construction activities can lead to soil erosion, and water and soil contamination due to uncontrolled water flow.

2. Construction of channels for conveyance of stormwater flows can lead to excessive soil erosion and soil and water pollution

3. Construction activities, if not planned well, can over compact soil, reducing rainwater infiltration and groundwater recharge

4. Poor drainage can lead to water accumulation, causing erosion and sedimentation while also creating potholes (a vector hosting concern) and impeding access. Uncontrolled water can also damage other infrastructure, dwellings, and belongings, limit livelihood opportunities, and cause stress. Poor drainage also provides conditions for vector breeding.

5. Poorly managed surface water run-off, household greywater, or flooding septic tanks can all lead to long-term contamination of water sources or the ground near the site, and also act as a host for vector-borne diseases.

6. Use of open earth drainage channels can lead to soil erosion, particularly in areas with steep slopes; or the formation of stagnant water pools in flat grounds.

Establish drainage channels, piped drainage runs under roadways, or planted earth banks to prevent soil erosion. Seasonal maximum drainage patterns should be considered, with mechanisms in place post-construction for monitoring. In these instances, gravel or concrete channels/pipes can be used to regulate wastewater flow.

1. Plan construction activities and site water flow to minimise soil erosion, and water and soil contamination

2. Carefully model stormwater flow and use materials, slopes, and routes to minimise soil erosion and soil and water pollution

3. Plan construction activities to avoid over compacting the soil by assessing ground type, using lightweight equipment or load spreading mats, excavated or till over compacted soil where over compaction has occurred

4. Design drainage to avoid water accumulation and stagnation. Establish drainage channels or piped drainage under roadways and/or construct roadside french drains and/or planted earth banks to reduce soil erosion. Seasonal maximum drainage patterns should be assessed, with mechanisms in place for post-construction monitoring

5. Map existing surface water run-off and design shelters and infrastructure to prevent excess run-off. Design household greywater capture and re-use facilities and assess surface and groundwater to ensure septic tanks will not flood and overflow

6. Only use open earth drainage channels where there is no alternative and on very gentle slopes. Size them to ensure they have plenty of capacity for peak flows

CASE STUDY: ACEH, INDONESIA POST-TSUNAMI HOUSING PROJECT

Houses in Aceh Besar District, Sumatra, Indonesia, were built after the 2004 Indian Ocean tsunami, as well as a newly constructed seawall that was built as a coastal barrier to protect residents from future tsunamis and storms surges. Unfortunately, the site plan and design for the housing project overlooked the fact that a significant quantity of freshwater flows from inland areas toward the ocean during periods of heavy rainfall and becomes trapped by the seawall before it is released into the ocean.

The recurring floods damaged the newly constructed shelter, water and sanitation systems, and roads, and have affected residents’ health and quality of life. As a short-term fix, a costly drainage system was installed. To prevent these types of problems and added costs in the future, project planners need to ensure that there is coordinated planning among a range of stakeholders beyond the immediate project area and must pay particular attention to the broader environmental context.

FROM: https://www.sheltercluster.org/sites/default/files/docs/GRRT%204%20-%20Strategic%20Site%20Selection%20and%20Development.pdf

# of shelter activities informed by drainage plans

% of linear meters of drainage channels that are properly designed to avoid erosion or contamination events

Prevention of environmental damage

Mitigation of environmental damage

Water and drainage assessment and design.