Property Drainage

Managing rain where it falls

This property will endeavour to manage rain and snow where it falls, before it can run off. The goal is to help to restore the water cycle and reduce runoff volume through infiltration, enhancing the forest, and rainwater harvesting and reuse. The overall aim is to help make our community of Gatineau Shores West function much like the forest before all the roads and homes were built.

This will mean using green features such as rain gardens, permeable permeable driveway and paths, bioswales, trees, dry ponds, rain barrels and cisterns. Doing so will help minimize the amount and quality of water flowing from the property into the river and road ditch.

In nature, most rainfall is absorbed into the ground, taken up by vegetation, and evaporated from foliage. Very little runs off the land. Climate change is making things worse by increasing the frequency of severe wet weather which has been a challenge for our road drainage.

Ditch description

The property has approximately 100' of frontage along Rue du Soleil. The ditch begins at the crest of hill on du Soleil, which also approximates the location of the southern property line, and descends 16" over 60' of shallow earth then descents 34" over a 36' wide rock slab then drops 14" over the edge of the rock slab into a well defined ditch that continues its descent along the road.past the northern property line. The elevation of the rock slab in the ditch is generally even with the road surface.

(photo 1)

Water flow

There is minimum property runoff into the 60' upper part of ditch because the depth of sandy soil on the property and a berm pictured in the below photo that maximizes the water retention capacity of the soil. The road profile illustrates water generally flows away from the ditch.

The 36' long rock slab across the driveway entrance generally has water flowing across it in the winter because of snow build up on the road but in the summer runoff can spill onto the road because of similar elevation with the road.

The remaining part of the ditch below the rock slab is deep and remains as repaired from phase 1 of the 2017 ditch project.

(photo 2)

An extensive depth of sandy soil and a berm outlined in orange minimizes runoff into the first 60' of ditch at top of hill.

(photo 3)

"A" marks beginning of rock slab extending across driveway entrance where road gravel that might have helped water flow across the rock has been graded away to form small water retaining embankments on both sides of the road as illustrated in the below photo 3.

(photo 4)

Driveway

Upper driveway A drains south to area with significant overburden to allow water to slow down and soak into soil. Lower driveway B designed to drain north to drainage swale C which enters ditch on the downside of the entrance rock slab (D in photo 1).

(photo 5)

Driveway is built on a foundation of local material consisting of stone and sandy soil to minimize the impact on the natural flow of water and covered with permeable angular rock and stone dust.

Conclusions

1. The upper 96' of the Rue du Soleil ditch has little influence on road drainage and conveys very little water as evidenced from the Oct 15, 2017 downpour and last winter's runoff.

2. Driveway use of the 36' long rock slab as an entrance feature was done to lessen the impact of water on this very shallow part of the ditch by using the driveway to help drain the water into the deeper part of the ditch.

3. The heavy downpour on Oct. 15 resulted in no sedimentation from the driveway onto du Soleil.

4. Ditch and driveway water hydraulics will be monitored during rain events and spring runoff for further understanding.

5. Any negative impacts on the road will be repaired.

6. Road surface in front of property will be raked to eliminate gravel embankments.

Reference

Green Communities Canada