Healthy Roads & Environment & Rainwater HarvestingTraining of Trainer Personnel on

Environmentally Sound Design and Implementation of Public Works-

Community Roads of the ProductiveSafety Net Program (PSNP)

Principles of Protecting

Roads from Water

Zeedyk, Bill. 2006. A Good Road Lies Easy on the Land: Water Harvesting from Low-Standard Rural Roads. Zeedyk Ecological Consulting, LLC., Sandia Park, New Mexico. 54 p.

“A Good Road Lies Easy on the Land…”

“If it is:•Is located on a landform where it can be readily and effectively drained (neither too steep nor too flat); •Is functional when used as intended (class of vehicle, season and suitable weather conditions); •has appropriate drainage features (closely spaced, properly situated and adequately maintained);

—Bill Zeedyk

“A Good Road Lies Easy on the Land…”

If it is:•preserves the natural drainage pattern of the landform; •conserves water; •does not cause or contribute to accelerated soil loss, lost productivity or water pollution; •does not encroach on wetland or riparian areas; and •is scenically pleasing.”

—Bill Zeedyk

“A road is not easy on the land

If it •collects, concentrates or accelerates surface or subsurface runoff; •causes or contributes to soil erosion; •impairs or reduces the productivity of adjacent lands or waters; •wastes water; •unnecessarily intrudes upon key habitats, stream channels, floodplains, wetlands, wet meadows or other sensitive soils; and •Is aesthetically offensive.”

—Bill Zeedyk

The Achilles’ heel of rural feeder roads is poor drainage

• When water is disposed of as quickly as possible (to protect the road) without regard to its source or where it goes, poor drainage results and water is wasted.

• By installing drainage features that not only protect the road from erosion, but also direct the water to buffered sites where water storage or infiltration can occur, landowners can realize the added benefit of harvested water while reducing maintenance costs.

—Bill Zeedyk

Guidelines for Healthy Roads & Environment

• Avoid using roads during wet weather or when too soft to travel over. Passage by even one vehicle during these times can cause rutting.

• If the road is too wet to travel, keep vehicles off it except for emergencies.

• Maintain drainage features in functional condition at all times.

• Remove blockages as they occur.• Keep ditches open, but do not remove vegetation

that does not impede drainage. Vegetation holds the soil in place, and increases infiltration.

• Watch for and remove accumulating sediment deposits and berms that interfere with proper road drainage, keeping water trapped on the roadway. Determine the sediment source and correct the cause. Is the sediment coming from the road surface, a ditch bank, a slump, or from an off-site source? Why is it accumulating? Is there an obstruction? Is there debris in the ditch? Is the grade too flat?

Guidelines for Healthy Roads & Environment

• When installing drainage features, return intercepted runoff to its natural path at the first opportunity. Walk out the flow path and be certain that water spilled from the roadway is not causing an erosion problem somewhere else. If so, pick an alternate path.

• Sediment deposition, not erosion, is the primary reason why drainage features fail. Minimize drainage failures by reducing sediment yield and transport. Gravel the road surface.

Guidelines for Healthy Roads & Environment

• Keep the grade of drainage features as steep or steeper than the roadway. The increased runoff velocity will tend to flush sediment through the drain rather than depositing sediments that clog it.

• Install drainage features at closely-spaced intervals.

• If possible, select drainage outfall sites that are buffered by vegetation and can absorb runoff or can accommodate concentrated flow with minimal erosion.

Guidelines for Healthy Roads & Environment

Water must flow easily off the road and to drainage ditches or adjacent

land

Water Harvesting From Roads?

• Can road runoff or diverted runoff be effectively returned to the soil and used to water grass, crops, other vegetation, or livestock or is it being lost to the nearest stream, ditch, or gully?

Why are roads potential rainwater harvesting options?

Why are roads potential rainwater harvesting structures?

• Roads tend to block and concentrate runoff and then discharge it at a few points.

• Discharged water can be collected and stored or infiltrated to recharge groundwater.

• Roadways generally produce 2 to 4 times as much runoff per unit area as non-roadways.

What types of rainwater harvesting systems are compatible with rural

feeder roads drainage works?

Micropond

• Probably most appropriate with roads. Why?• Period for Implementation: Only during dry

season and minimum of one month before rains likely to occur.

Microponds* along road

* or other water storage/infiltration structures

Similar to microponds with bunds

Types of Microponds

Cemented: Useful for small-scale irrigation both during (supplementary) and few months after the rainy season.Not cemented: Useful mostly during the rainy season as supplementary irrigation during dry spells and to recharge ground water.

Micropond Design• Round shaped micro-ponds (cemented and not

cemented)– For detail design procedures consult guidelines

provided by the MoARD/BoARD in each region. Usually 4-6 meters radius and 3-4 meters deep. The cone of the pond is truncated at Its bottom allowing for 2-3 meters diameter flat bottom.

– Appropriate for small microcatchments (400-1000m2), supply of excess runoff from feeder roads (30-100m), footpaths small closures, grazing areas compounds. etc. The bottom and sides of ponds should be tightly stone paved/faced using mortar (cement/sand of 1/4), reinforced with mesh and plastered (cement/sand ratio of 1 2-3). Moisten the cemented wall & bottom for 2-3 weeks after construction to avoid cracks.

Micropond Design

• Clay blankets: Applicable In areas with medium textured soils. Clay blankets 20-30 cm compacted to decrease seepage. While applying the clay blanket moisturize and compact every 3 cm. Walls can also be stone faced and plastered using local mortar.

• AII microponds need to be shaded to prevent malaria if in a malaria prone area and/or stock with mosquito larvae eating fish.

Questions or comments from trainees or other

trainers?

Training of Trainer Personnel on Environmentally Sound Design andImplementation of Public Works-

Community Roads of the ProductiveSafety Net Program (PSNP)

June 13-24, 2011Ghion Ambassel Hotel

Dessé, Ethiopia