6. Monahan Drain Catchment: Challenges/Issues

Water Quality/Quantity

Surface chemistry water quality in the Monahan Drain catchment is “Poor” at both monitored water quality sites for the 2010-2015 period. The scores at these sites are largely influenced by frequent high nutrient concentrations, bacterial pollution, occasional metal exceedances and elevated chloride levels

Instream biological water quality conditions in the Monahan Drain are unknown

Natural hazard lands have not been identified

Effect of climate change on the hydrologic function of the Jock River subwatershed and associated natural hazards (flood risk) posed to the built/urban areas of the catchment are not fully understood

Existing hydrological and geochemical datasets and assessments (academic, RVCA, others) are only recently available and/or are not being considered in the characterization of the numerous hydrologic functions of the Jock River subwatershed. Further, there is a dearth of hydrologic information (hydroperiod, groundwater/surface water interactions, geochemistry) about the wetlands that remain in the Jock River subwatershed

Headwaters/Instream/Shorelines

‘Natural’ vegetation covers eight percent of the riparian zone of Monahan Drain and its tributaries (Figure 24) and is below the recommended 30 metre wide, naturally vegetated target along 75 percent of the length of the catchment’s watercourses

No information available about instream aquatic and riparian conditions along Monahan Drain

Land Cover

Woodlands cover seven percent of the catchment and is below the 30 percent of forest cover that is identified as the minimum threshold for sustaining forest birds and other woodland dependent species (Figure 22)

Pre-settlement wetlands have declined by 99 percent and now cover less than one percent (12 ha.) of the catchment (Figure 23)