MAFF Watercourse Classification and Agricultural Ditch Maintenance

Watercourse classification and fish presence information are useful for landowners, local governments and agencies as planning resources to assist in habitat improvements, watercourse maintenance and conservation. Used in conjunction with Agricultural Watercourse Maintenance Guides and Riparian Self Audit Handbooks, this information can be used to establish watercourse protection and ditch maintenance practices. Watercourse classification uses data acquired by Sensitive Habitat Inventory and Mapping (SHIM) methods and incorporated into local GIS databases.

In 1995, Fisheries and Oceans Canada (DFO) changed its way of managing for habitat, requiring authorization to clean ditches. A committee was struck to find ways to do maintenance. This process led to the recognition of three categories: natural streams, channelized streams and constructed ditches.

Natural streams are historic watercourses that have not been channelized or have not recently been altered. Often characterized by a meandering channel, they may only flow seasonally and may have intermittent or subsurface flows.

Channelized streams are permanent or relo-cated streams that have been diverted, dredged, straightened and/or dyked. They often carry water from more than one property, upland areas or wetlands.

Constructed ditches are watercourses that drain individual properties or local areas. They have been constructed by landowners for the purpose of removing excess stormwater and runoff, and may be a source of irrigation water in summer.

DFO authorization is required for maintenance work on constructed ditches if the work is expected to result in the harmful alteration, disruption or destruction of fish habitat (as determined by a habitat biologist). Guidelines are provided, depending on the condition of the ditch, so work can be done with minimum red tape. The benefit for agriculture and agencies is fewer approvals required. The process is thoroughly outlined in the Agricultural Watercourse Maintenance Guide.

Once the type of watercourse has been defined, the presence or absence of fish must also be determined. There are three categories that can be used: fish presence, fish absence and unknown fish presence. The watercourse classification system is then mapped using a combination of line types and colours.

The watercourse classification system is often incorporated into a GIS. Different information collected by other agencies can also be incorporated into the various layers. The watercourse classification system would be part of the water features layer.

The objective is to provide for adequate drainage and irrigation of productive agricultural lands while protecting valuable fishery resources. The Agricultural Watercourse Maintenance Guide is intended to provide farmers and municipalities with clear direction on how to proceed with maintenance works under various conditions. At the same time the Guide will reduce the need for the Ministry of Water, Land and Air Protection (MWLAP) and DFO to issue approvals, authorizations and/or letters of advice for routine maintenance of constructed agricultural drainage ditches. This is accomplished by streamlining contact requirements for constructed ditches through processes outlined in the Guide, and the development of protocol agreements between proponents and the environmental agencies.

The definitions of natural streams, channelized streams and constructed ditches have been used to classify watercourse channels in the Fraser Valley Regional District Habitat Atlas (see FVRD Habitat Atlas Case Study). Natural streams and constructed ditches were classified first. The remaining watercourses were then classified as channelized streams.

The Habitat Atlas has used the best available data to locate, map and classify watercourses. Techniques used include aerial photo interpretation, on-the-ground Global Positioning System (GPS) information using the SHIM method, contact with landowners and/or visual inspection of the areas in question.

The Agricultural Ditch Maintenance Guide project has been in progress for four years. It was piloted in the Fraser Valley first, in 1999 and 2000; it will be extended in 2002 to Vancouver Island, and eventually over the rest of the province.

Watercourse classification and fish presence information are used by landowners, local governments and agencies as planning resources to assist in habitat improvements, watercourse maintenance and conservation. Used in conjunction with Agricultural Watercourse Maintenance Guides and Riparian Self Audit Handbooks, this information can be used to establish what riparian assessments may be required for habitat protection, implementing the ditch maintenance guidelines and determining building setbacks.

The Agricultural Watercourse Maintenance Guide uses the classifications to determine agency requirements for contact when doing work in and about watercourses (i.e. ditch maintenance), and in the riparian audit to develop watercourse protection measures for channels in agricultural areas.

Watercourse classification and the Agricultural Watercourse Maintenance Guides are ongoing projects.The watercourse classification initiative contributes to the integration of multiple kinds of land and resource data in GIS systems, where it helps build a comprehensive database of information that can be accessed by a variety of users for different purposes.

Recommendations for the Community Mapping Network:
Users want different things from the same data. When the data is collected, therefore, collect it all at once, to facilitate use of the database by different users. Open up the vision to ensure collection of information for use by all. It has to be collected by local governments, since they have the need and the resources — i.e. the vision. Collect a common datasheet and share it.

This case study was prepared by Glen L. Porter with assistance from Ted Van der Gulik and Janine Nyvall (Ministry of Agriculture, Food and Fisheries) for the ‘Planning Sustainable Communities Workshop’ sponsored by the Community Mapping Network (www.shim.bc.ca) and the Township of Langley. The workshop, held March 15, 2002, showcased examples of mapping as a tool for sustainable planning. These examples were compiled in the workshop’s summary document ‘Planning Sustainable Communities’ by Glen Porter of G.L. Porter Consulting with support from Brad Mason (Fisheries and Oceans Canada); Rob Knight (Ministry of Water, Land and Air Protection); Gretchen Harlow (Environment Canada); and, Kathleen Moore (Environment Canada). These case studies were later added to the BC Stewardship Centre Case Study Library by Sara Muir Owen with support from Rod Silver (Habitat Conservation Trust Fund).

Ministry of Agriculture, Food and Fisheries. 2001. “Resource Management Factsheet” (pamphlet).

Partnership Committee on Agriculture and the Environment. 2001. “Agricultural Watercourse Maintenance Guide: Lower Fraser Valley and Vancouver Island.” Ministry of Agriculture, Food and Fisheries and Ministry of Water, Land and Air Protection.

Ministry of Agriculture Food and Fisheries
Resource Management Branch
Ted Van der Gulik
1767 Angus Campbell Road
Abbotsford, BC Canada
V3G 2M3
Email: ted.vandergulik@gems8.gov.bc.ca