Riparian Buffers: Function, Management, and Economic Implications for Agriculture

Project Overview

Project Type: Research and Education
Funds awarded in 2003: $242,035.00
Projected End Date: 12/31/2007
Matching Non-Federal Funds: $33,917.00
Region: Western
State: Washington
Principal Investigator:
Jon Johnson
Washington State University - Puyallup Res. & Ext.

Annual Reports


  • Agronomic: corn, potatoes, grass (misc. perennial), hay
  • Additional Plants: trees


  • Animal Production: manure management, preventive practices, feed/forage
  • Crop Production: agroforestry, forestry, nutrient cycling
  • Education and Training: decision support system, demonstration, extension, on-farm/ranch research, technical assistance
  • Farm Business Management: budgets/cost and returns, feasibility study, agricultural finance
  • Natural Resources/Environment: afforestation, hedges - grass, habitat enhancement, indicators, riparian buffers, riverbank protection, soil stabilization, wildlife
  • Production Systems: agroecosystems
  • Sustainable Communities: partnerships, sustainability measures


    This project successfully characterized the functioning of 3 riparian buffers over a 4-year period as related to non-point pollution coming from adjoining farms. Factors affecting buffer function included depth to groundwater, species, age and time of year. In addition, we quantified the impact of buffer shade on two crops, silage corn and blueberry. Lifetime costs of buffers on potato farm budget were $11,000 per acre and even higher for blueberry and dairy production in the Skagit River Delta. Four interactive farm enterprise budgets were created for potato, blueberry, raspberry and dairy, and are available to the public at

    Project objectives:

    Our goal was to identify what constitutes a functional riparian buffer to protect water quality and improve salmon habitat on agricultural land in western Washington, and to determine the economic impact of such buffers on farm enterprises. Specific objectives include:
    1) To determine the effects of buffer width, species composition and management on buffer function including nutrient removal, sediment reduction, shade, and bank stabilization;
    2) To conduct economic impact analysis of different riparian buffer designs on individual farm enterprises;
    3) To develop and disseminate buffer recommendations and decision-making tools to farmers, farm agencies, regulators and policy makers dealing with farmland along watercourses in western Washington.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.