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Appendices

Appendix A - Information Requirements

Types of information requirements that may be applicable to a freshwater intake proposal are highlighted below. While this listing is not intended to be all inclusive, it indicates information that may be necessary to enable regulatory agencies to review a water intake and fish screen proposal. The information highlighted below considers Section 30 and other sections of the Fisheries Act. These information requirements may also address other Federal, Provincial, and Municipal legislation and policies.

General and Site Information

• gazette or common name of the watercourse
• location of the watercourse
• type of watercourse (e.g., pond or stream)
• type of water intake
• other activities associated with the development or construction of the intake/screen structure

Biophysical Information

• fish presence, species, and possible fish size or fish habitat conditions at the project site
• physical description of the watercourse at the intake site, including channel width and depth, direction and velocity of water currents, variations in water levels, sediment transport processes, lateral or channel grade movement, debris loading, etc.
• location and position of the intake within the watercourse, including dimensions, alignment, depth in the water column, wetted area, etc.
• description of the site features and characteristics, including site access

Water Use Information

• purpose of water withdrawal
• average rate, or ranges of rates, of withdrawal from the watercourse
• duration and time of withdrawal
• estimates of ranges of flow (i.e., daily, weekly, monthly) in the watercourse during times of withdrawal with dates and times of year (with particular consideration to periods of low flow)
• expected effects of withdrawal on existing watercourse (e.g., drawdown, downstream dewatering, etc)
• description of structures or activities associated with the development of the intake
• whether the application is for a new intake, or re-development or upgrading of an existing structure

Other Information

• site plans/sketches indicating intake site and location (detailed on 1:50,000 topographic map)
• photographs/video of the site are often useful

Fish Screen Information

• screen open and effective areas
• physical screen parameters with respect to the intake and the watercourse
• screen material, method of installation and supporting structures
• screen maintenance, cleaning or other special requirements

Appendix B - Sample Calculation

A proponent wishes to withdraw water at a rate of 0.075 m³/s from a nearby pond. The pond supports populations of brown trout, brook trout, and American eel. The intake is proposed to be cylindrical with the ends solid and #60 wedge wire screen around the cylinder.

What size must the intake screen be to satisfy the guideline requirements?

There are 4 steps to finding the answer:

1. Determine the fish swimming mode.
2. Determine the open screen area.
3. Determine the effective screen area.
4. Determine the dimensions necessary to produce the effective screen area.

1.  Fish Swimming Mode

The fish swimming mode is found from Table 1. Brook trout and brown trout are listed as subcarangiform swimmers while the American eel is an anguilliform swimmer.

2.  Open Screen Area

Table 2 lists the required open screen area for both subcarangiform and anguilliform swimmers under flows up to 125 L/s (2000 US gpm). To use the table, it is first necessary to convert the flow from cubic metres per second to litres per second.

For a flow of 75 L/s, Table 2 indicates that the open screen area must be:

• 0.69 m² for subcarangiform swimmers, and
• 1.96 m² for anguilliform swimmers.

The higher number (1.96 m²) is the more stringent requirement; therefore, it is used in the calculation of effective screen area.

3.  Effective Screen Area

The screen material in this case is # 60 Wedge Wire. A review of Table 3 indicates that the % Open Area for this material is 63%. With this value and the previously determined area from Step 2, the following formula is used to determine the Effective Screen Area.

4.  Dimensions of Intake Screen

Figure 2 lists several common screen shapes and their respective area formulae. For a cylindrical screen where the ends are solid and screening is around the cylinder, the following formula applies:

The unknown dimensions are diameter (D) and length (L). These dimensions are determined by choosing a value for one and solving the equation for the other.

If the diameter is 0.600 m, then the length follows as:

A 0.600 m diameter, 1.65 m long cylindrical screen would meet the design requirements. It should be noted that the dimensions given are representative of the screening area only; they do not include any screen that may be blocked by framing, etc. By comparison, if the pond only supported trout (subcarangiform), a 0.600 m diameter, 0.58 m long cylindrical screen would meet the design requirements.

Appendix C - Units of Conversion

Appendix D - DFO Regional Contacts

Local DFO offices should be contacted. Other appropriate regulatory agencies should also be contacted.

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