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Road Water Management for Climate Resilience

                                                                                                                                                  Photo Courtesy of the Star,Kenya
Climate change is gradually putting at risk millions of local’s country wide as well as coastal cities; with major global investments being channeled towards the transport infrastructure,  Road are crucial to transport inland across the country but are we sure that our roads can withstand the effects of climate change?

Action is needed to diagnose systematic weaknesses and adapt transport systems and infrastructure that can withstand expected climate impact such as dynamics in rainfall patterns, flooding and sea level rise as well as extreme weather events. A better understanding is required on existing vulnerability assessment tools, cost effective engineering measures and technologies all geared towards a robust, redundant and resilient design on the road network.

Roads have a major impact on climate resilience; they determine the way water moves across the terrain. Roads can impede the flow of water, concentrate it in a few places or may also convey water and act as a drain.

Roads built in a certain way may often cause considerable damage and undermine climate resilience – on risk exposure, readiness, response and assurance. They cause erosion, flooding, sedimentation, drainage congestions which greatly escalates the effects of rainstorms and impacts of drought.

Using real world case studies from different fields of engineering we can change this; roads can be used to systematically harvest water and to ward off and mitigate floods.  A case study in Ethiopia shows that more than 1 million people benefited from road water harvesting programs. Water Management with roads can result to an increase in income to more than 30%; increasing the resilience of local communities to droughts and minimize road damages.

@eclimateadvisory, we arguably say that climate funds should be used to retool roads to promote climate resilience.

An investor’s point of view

  1. Management of water with road infrastructure presents a triple win; - reduced degradation of landscapes; reduced road maintenance and drainage costs, productive and consumptive use of water harvested with the roads.
  2. Best option for climate resilient infrastructure; - costs in association to building roads that harvest water manage floods, provide a cheaper alternative to building road bodies with heavy new design specification that deal with the expected impact of precipitation and other climate change effects.
  3. Offers value for money; with minimal costs compared to overall outlays for road investments, repair/ maintenance; Additional costs on designing modifications to include road water management from start can be estimated at 5% of original investment planned for the road infrastructure.

Knowing all this, we should look to incorporate engineering and non – engineering considerations to designs and road upgrades that will last longer and cost less to maintain.

Engineering options to be considered to improve road water management may include but not be limited to;

  • Side Drainage; - Drainage on road sides should consider the greater rainfall intensity and should be able to accommodate the increased volume and intensity discharge.
  • Road Surface;- High peak temperatures may have asphalt better able to withstand softening or melting; which ideally can be achieved through adjusting the binder composition of the asphalt.
  • Bridges and tunnels; - Peak river discharge depends primarily on mudflows with large buffering upstream by wide flood beds. Using glaciers, mudflows can be reduced. Also road crossings could be used to mitigate risks upstream.
  • Costly mitigation practices like retention dams can be built; widening rivers where possible to reduce maximum water level under the bridge as well as installation of acoustic water level sensors as an early warning system can be adopted. In addition concrete used on bridges should be adapted to a higher frost standards.

Non – Engineering aspect of the same includes;

Off-setting capacity building and management measures on climate change impacts for example, road side trees that reduces effect of heat and erosion on our roads.

Involving stakeholders concerned with land degradation and having water for irrigation through teaming up and conducting regular cleaning of rivers and channels upstream and downstream to reduce sediment and co-currently maintain water discharge capacity during mudflow.

Conclusively, training, capacity building and awareness creation on climate change adaptation and development of guidelines for the transport and environmental sectors are also recommended.