Irrigation Canal Maintenance & Management


ENVIROKONSULT™ has more than 20 years of experience…

in the design, implementation and operation of preventative maintenance programmes for the control of aquatic vegetation in irrigation canal systems.  Our services to Irrigation Farmers, Irrigation Boards, Water User Agencies and the Department of Water Affairs include the following:

  • Algae and aquatic vegetation control in canals;
  • Algae and aquatic vegetation control in balancing dams, irrigation dams, dividing structures and other canal infrastructure;
  • Maintenance of canal servitudes (our species manipulation concept is a popular approach to keep vegetation in canal servitudes manageable without costly regular mowing);
  • Implementation and operation of Canal Water Quality Monitoring Programmes, as required by the Department of Water Affairs and for GlobalGAP / EuropGAP certification.

The excessive growth of aquatic vegetation in canals has the following impacts on a canal system

  • Water loss as a result of flooding of canals;
  • a negative influence on the hydraulic capacity of the canal;
  • overestimation of water supplied;
  • significant operational problems;
  • slab failure due to spilling;
  • water cannot reach the irrigators at the tail end of a canal system due to reduced capacity;
  • inefficiency of the water delivery system.

ENVIROKONSULT™ to the irrigation scheme manager’s rescue!

To address the problem of excessive growth of aquatic vegetation in canal infrastructure, ENVIROKONSULT™ firstly analyses the situation and then design a suitable management programme for each individual water conveyance system on a site-specific basis.  Canals are treated on a pre-set schedule based on the canal systems unique requirements as well as the specific vegetation species present in the system.

MAGNACIDE™ H Herbicide best in its class for aquatic vegetation control in canal systems…

For more than 50 years MAGNACIDE™ H Herbicide (L8655) has proven effective control of submerged aquatic vegetation and algae in both concrete-lined and unlined irrigation canals throughout the world.  MAGNACIDE™ H Herbicide (L8655) was registered by ENVIROKONSULT™ as an aquatic herbicide with the Department of Agriculture in South Africa for all submerged macrophytes (vascular plants) and algae occurring in water conveyance systems.  MAGNACIDE™ H Herbicide (L8655) provides excellent control on all submerged aquatic vegetation and algae and is recognized as the best in its class in the world.

The Concept

  • ENVIROKONSULT™’s preventative aquatic vegetation management plan entails the preset treatment of canals on a specific frequency throughout the season.
  • Aquatic vegetation is removed before they can impact on the operation of the canal system.
  • A treatment schedule is worked out with the scheme manager to accommodate off-periods (dry periods) and general maintenance on the system with minimum disruption of water delivery.
  • The majority of South African canals will require six (6) to eight (8) MAGNACIDE™ H Herbicide (L8655) treatments per season.  Some systems may require up to ten (10) treatments.

Advantages of implementing ENVIROKONSULT™’s preventative maintenance aquatic vegetation management plan

  • Canal capacity is restored within 24 hours after a canal treatment;
  • Treated water can be applied directly without any withholding period to crops – no down time of the irrigation system during canal treatments is necessary;
  • No interruption of irrigation water scheduling;
  • Cost effective:  herbicidal treatment of aquatic vegetation is more cost effective than the physical or mechanical cleaning of the canal;
  • This is the most effective management methodology of aquatic vegetation in water conveyance systems;
  • Full capacity delivery throughout the system;
  • Water loss can be cut by 20% in some canal systems.  In many cases the reduction in water loss will compensate for the cost of the canal treatment programmme;
  • Target plants and algae disintegrate totally – no clogging of grids and siphons;
  • An increase in the quality of irrigation water as MAGNACIDE™ H Herbicide (L8655) is also a biocide, killing harmful bacteria such as E. coli and others.
  • MAGNACIDE™ H Herbicide (L8655) removes algae and bacterial biofilms from micro irrigation systems and reduces clogging of filters and nozzles;

Reduction in canal maintenance:

  • Less damage to canals as with mechanical cleaning;
  • Less erosion;
  • Decrease in sediment volume in canal;
  • Reduction in canal friction (Manning’s friction factor);
  • No corrosion on any metal structures in canal system.

A happy irrigation scheme manager and satisfied irrigators!


ENVIROKONSULT™’s canal management plans are operated under supervision of professional environmental scientists with vast experience in the water environment.  Our scientists are trained in all facets of the programme and are licensed with the Department of Agriculture as Pest Control Operators (PCO’s) according to the requirements of Act 36 of 1947.