ABSTRACT
In 1981, the first scientific forest drainage study in Alberta was initiated on a treed fen in the Saulteaux River drainage basin in central Alberta under the auspices of the Alberta Forest Service. This chapter develops the techniques for designing drainage systems and measuring their performances. Evaluation of drainage network performance is an important part of the study. Results from drainage studies in European forests suggest that the optimum depth to water table for different tree species ranges from 0.18 to 0.50 m, measured at the midpoint between ditches. The drainage system performance was rated acceptable if, during the growing season, the water table approximated, on average, a depth of 40 cm without staying above this level for more than 14 d consecutively. Continuous traces of water table levels at the midpoints between ditches obtained for the predrainage and postdrainage periods show the water table fluctuations above and below the norm during the 6-year interval.
