DNS - ITS IN THE STORMWATER REPORT - Landsverk Appendix C - Operations and MaintenanceAPPENDIX C
The following specified structures and/or BMP's are provided herein for the single-family development
at: 19515 94" Place West Edmonds, WA 98020 (see attached Map 1 for Lot Description and Details):
Permeable Pavement
Infiltration Trench/Gallery/Drywell
O Detention Pipe/Tank/Vault
O Concentrated Flow Dispersion
O Other:
O Infiltration Tank/Vault
O Sheet Flow Dispersion
O Reduced Impervious Footprint
O Rain Garden / Bioretention Cell
Stormwater system consists of infiltration pits with tightline downspout drains to yard drains and
driveways/walkways of permeable materials for direction infiltration. For design details please reference
Drainage Report dated May 2023. No maintenance requirements are provided for newly planted or
retained landscaping as they are not a BMP pursued in this project.
Operations and Maintenance Standards
The Owners of the Property agree that the Property contains one or more stormwater
management facilities referred to as a `BMP", which was installed to mitigate the stormwater
quantity and quality impacts of some or all of the impervious or non-native pervious surfaces
on the property.
a. For infiltration -based BMPs, the BMP shall include all pretreatment devices upstream,
the infiltration facility, and a minimum of 3-feet of soil beneath the infiltration contact
layer, defined as the elevation at which runoff enters native soils.
b. For bio-retention or rain garden BMPs, the BMP shall include all pretreatment devices
upstream, the retention facility, the vegetation within the retention facility, and a
minimum of 3-feet of soil beneath the infiltration contact layer, defined as the elevation
at which runoff enters native soils. While specific plants are not necessarily required, a
quantitative amount of vegetation coverage is required and may be subject to
maintenance requests per Section 5.
c. For dispersion based BMPs, the BMP shall include all pretreatment devices upstream,
the dispersion mechanism/device, and all elements of the downstream vegetated flow
path, including restrictions on slopes and surface materials, as required by ECDC 18.30.
d. For detention BMPs, the BMP shall include all pretreatment devices upstream, the
detention device, and the control structure device.
e. For reduced impervious footprints, the BMP shall include all areas which are used as
mitigation credits, including a full ten -foot (10') driveway width when using wheel strip
driveways.
The Owners shall maintain the size, placement, and design ofthe BMP as depicted on the approved
site plan, Exhibit B, attached hereto and incorporated herein by this reference as if set forth in
full, and design details shall be maintained and may not be changed without written approval
either from the Engineering Division of the City of Edmonds or through a future development
permit from the City of Edmonds. Chemical fertilizers and pesticides shall not be used where a
BMP is located. All costs ofmaintenance and repair shall be the sole responsibility of the Owners.
3. The Owners shall inspect BMPs annually for physical defects. After major storm events, the
system shall also be checked to ensure that the overflow system is working properly. The Owners
also shall maintain all BMPs so they function as designed on a year-round basis.
Refer to Table 1 for frequency and description of maintenance required for BMP's applicable to
the property herein. Final engineering report to be provided to Owners in conjunction with
descriptions below for best maintenance practices:
Table 1— Maintenance Checklist
STRUCTURE OR BMP
FREQUENCY OF
MAINTENANCE DESCRIPTION
DESCRIPTION
MAINTENANCE
Permeable Pavers
Annual
Check pop-up drains to monitor infiltration rates.
Dry Wells
Annual
Ensure CB's are clear of all debris and maintain
cleanouts er City of Edmonds SD-638.
Map 1— Site Plan & Description
Exhibit A
Legal description
PARCEL A:
LOT A OF CITY OF EDMONDS SHORT PLAT S-9-89' RECORDED UNDER AUDITOR'S FILE NUMBER
8906200263, BEING LOT 3 AND PORTION OF LOT 4 OF CITY OF EDMONDS SHORT PLAT NO 5-12-81
RECORDED UNDER RECORDING NUMBER 8408290222, BEING A PORTION OF LOT 58, EDMO DS
SEA VIEW TRACTS, ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 3 PAGES 76
AND
TRACTS 17 AND 25 .PUGET SOUND MACHINERY DEPOT FIVE ACRE TRACTS, ACCORDING TO
THE
PLAT THEREOF, RECORDED IN VOLUME 5 OF PLATS, PAGE 47, RECORDS OF SNOHOMISH
COUNTY, WASHINGTON.
PARCELB:
TOGETHER WITH AN EASEMENT FOR INGRESS AND EGRESS AS DESCRIBED IN INSTRUME T
RECORDED UNDER RECORDING NUMBER 1423034 AND DESCRIBED AND DELINEATED IN
SHORT
PLAT RECORDED UNDER RECORDING NUMBER 8408290222 AND DELINEATED IN SHORT PLAT
RECORDED UNDER RECORDING NUMBER 8906200263,
EXCEPT ANY PORTION THEREOF LYING WITHIN THE ABOVE DESCRI8ED MAIN TRACT.
SITUATE IN THE COUNTY OF SNOHOMISH, ST ATE OF WASHINGTON.
LPB