Research and Development Office

Nuisance Aquatic Vegetation Control in Water Delivery Systems: mapping and monitoring vegetation biomass

Project ID: 1725
Principal Investigator: Dale Lindeman
Research Topic: Supporting Irrigation Districts
Funded Fiscal Years: 2015, 2016 and 2017
Keywords: nuisance aquatic vegetation, irrigation, water delivery systems, water quality, vegetation biomass

Research Question

What combined set of tools, technology, and resources could provide managers of irrigation entities the means for efficient and effective control of nuisance aquatic vegetation (NAV) in water delivery systems (canals and associated water bodies)?
Numerous factors influence growth and distribution of NAV in water delivery systems, and in turn, there are multiple options for minimizing or mitigating associated adverse consequences. Essentially, "what", "when", "where", and "how" are critical considerations managers make in optimizing treatment effect on the target NAV, maintaining environmental quality, and allocating limited operational and management resources. A previous Science and Technology study (Nuisance Aquatic Plant Control in Water Delivery Systems, Project ID: 6688) found that in taking a comprehensive approach to NAV control, an analytical decision support capability is necessary. This includes tools to first identify and understand NAV issues within a particular system, and secondly have adequate information to select and implement an effective control option.
The previous study focused on identifying alternative solutions to NAV control using mechanical removal and herbicidal treatment. The premise was that correlations of NAV occurrence with canal characteristics and local environmental factors would reveal modifiable conditions that could be manipulated to discourage NAV growth. The study found that for many water delivery systems within areas served by Reclamation, effective control of NAV requires treatments using herbicides. This proposed study builds on those findings and defines a comprehensive approach as one in which multiple factors are taken into account, such that whatever NAV control method is used, it is appropriate and as effective and efficient as possible. The proposed study will therefore identify tools, technology, and resources that managers of irrigation entities can use to evaluate and address multiple aspects of NAV control.

Need and Benefit

The western U.S. is predominantly arid and highly dependent on a network of reservoirs and delivery canals for agricultural water distribution. NAV, such as filamentous algae and rooted aquatic macrophytes, are wide-spread in these water distribution systems. Impacts from NAV can be severe and control can be costly. Flow through water delivery systems can be greatly reduced or completely obstructed by the growth of NAV. In addition, NAV can impair the performance of, if not damage, intake structures, pumps, and other irrigation equipment. Canal operators and irrigation districts must expend operation and maintenance resources to physically remove NAV from the systems and/or purchase and apply aquatic herbicides. Financially, this can be from 10% up to 25% of the annual operating budget for these entities. Chemical treatments are becoming increasingly difficult to implement given the strict environmental regulation associated with the herbicides. Increased effectiveness and efficiency in all aspects of NAV control could help to alleviate issues around implementation.
Currently many managers rely on the increasing presence of NAV on screens and trash racks as a trigger for application. This approach may miss the optimal application period and is reactive rather than proactive. The proposed tools could provide managers with a cost effective means to increase optimal timing of NAV control. Data collection to monitor life cycle requires minimal investment and over time could serve as valuable predictive tools for planning and scheduling treatments. The investment in equipment to measure vegetative biomass where visual observation is impractical amounts to approximately 1% of the average annual costs irrigation entities expend on NAV control. An important component of this study is to evaluate and assess the cost savings realized by incorporating the proposed tools in management and NAV control.
The study area includes five (5) irrigation entities within the Great Plains, Lower Columbia, Mid-Pacific, and Pacific Northwest regions. The participants are interested enough to actively engage in seeking solutions that could help reduce NAV control costs. Successes demonstrated in this study will surely be adopted by others. The study results will be presented in workshops and regional conferences attended by irrigation entity managers in addition to being distributed by Reclamation operations and management personnel.
This proposal is the product of S%26T scoping project (Project ID 6688). Information was gathered from irrigation entities relating to current approaches to NAV control and outstanding issues needing to be addressed. The proposal has been developed on the basis of that information and reviewed by all participants.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Nuisance Aquatic Vegetation Control in Water Delivery Systems: mapping and monitoring vegetation biomass (final, PDF, 1.4MB)
By Dale Lindeman
Research Product completed on September 30, 2017

Nuisance Aquatic Vegetation Control in Water Delivery Systems: mapping and monitoring vegetation biomass (final, PDF, 1.4MB)
By Dale Lindeman
Research Product completed on September 30, 2017

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