Urban Sprawl - Maple Ridge?
This seven lot subdivision proposal at 28491 Dewdney Trunk [RZ/083/06] is part of the watershed of Whonnock Creek and the District of Maple Ridge have taken steps to protect Whonnock Creek and by connection Whonnock Lake. These steps include expropriation procedures of lands and the construction of a dyking system so that water levels of Whonnock Lake are maintained.
I do understand that the application reflects some of the OCP guidelines and has included some positive steps for “Rain Water Management”.
What we know!
The seven proposed lots would need the following:
- Seven Wells. Each well should produce at least 600 gals per day
- Seven Impervious surfaces. The housing foot print of the proposed homes will be 2500-3500 sq ft for a total of approx 15000 - 22000 sq ft of impervious surface.
And then we have an impervious street surface of approx 9000 sq. ft. Total impervious surface approx 31000 Sq ft which is approx 3/4 of an acre. What steps have been taken to reduce this impervious area? These days you can use pervious ashphalt, brick walkways and patios and rain garden surfaces for rain run-off.
What we don’t know
- What is the dollar amount of the security as part of the Watercourse Protection Development Permit [required to ensure that the Development Permit Guidelines are met]. For large-scale applications the environmental security deposit is 2.5 % of the total construction costs, while smaller projects the deposit is $1500 … so how much money?
- Is there a Tree Inventory prepared by a certified arborist:
- so the District can clearly determine areas that the developer has suggested as being “limits of clearing?” and
- so that the vegetative / tree health in the proposed conservation zone be determined and ensure that this area is not a future liability to the District. We need to insist that these conservation areas are healthy! - The Historic Base Line flow levels for this part of Whonnock Creek to ensure that downstream water flows reflect pre-development flows. Note Sec 8.9 of the Official Community Plan states that pre-development flow regimes are to be maintained. Accurate data for the base flows [low flows] as well as reducing high flows is required so that there isn’t any disruption to the integrity of the watercourse and the living and movement of aquatic life. Note the photo of beaver lodge and dam below!
- The soil stratigraphy and the ability of the soil to retain water or not. This soil report is required in other districts, particularly when a watercourse is involved. [Coquitlam]
- What are the proposals for the re-vegetation of the drain-off areas for each building site and for each of the impervious driveway areas.
What we do know:
In the Executive Summary of this application the Engineering Department stated that, The lands to the east were recently subdivided and built on. These lands were subdivided over 15 years ago and since that time a higher level of awareness of sustainability is now reflected in the Official Community Plan.
The District had to extend the water system eastward to the Garibaldi St and McNutt subdivision due to a failure in a private water system [yes each home owner had a property assessment to cover these costs] However, at this site there is the BCIT woodlot between it and Garibaldi St [the distance is approx 2 kms.] so if a well water failure occurs in the future will this subdivision be a capital project paid for by the general public?
A significant number of residential homes located on these rural locations have suites [Whispering Falls, Rock Ridge] - due to the basic economics of affordability!
- Suites whether registered or not will increase demand on well water and septic systems so a Ground Water Impact Assessment Report should be required as all homes south of this lot are also on a well systems.
There is no provision for the densification of the tree and vegetation cover even though there is a housing densification.
The District should have a “Wildlife Habitat Assessment Report” as there is evidence of beaver activity in the South Eastern area of this property.
Beaver lodge in top center of photo taken 13 February 2008. Photo credit: © 2008 Ken Hemminger
If the District of Maple Ridge wants to protect Whonnock Creek and by extension Whonnock Lake we need to have more information for an educated decision on this subdivision application.
Ross Davies — February 14, 2008 @ 4:30 pm
Whonnock Creek is a producer of wild coho salmon, and it’s catchment has not been significantly impacted by traditional “curbs and gutter” stormwater management. Such a technique, if applied here, would to me not only be out of character for this area but could quite possibly impact most of this already high-energy watercourse. I would like to see all roof and property runoff “disconnected” and returned to groundwater.