[Ord. No. 2695, Added, 2-16-2016]
An application shall be made on such forms and contain such
information as the City Manager may require. If a railroad-highway
crossing provides or will provide the only access to land that is
the subject of the application, the applicant shall indicate that
fact in the application.
[Ord. No. 2695, Added, 2-16-2016]
The City Manager shall administer this Code, and may furnish
additional policy, criteria and information including specifications
and procedures for the proper implementation of the requirements of
this Code. This information includes the Lake Oswego Stormwater Management
Manual (Manual).
The City Manager is delegated authority to adopt, revise, and
update the Manual as necessary. The Manual may be modified from time
to time, at the discretion of the City Manager, based on improvements
in engineering, science, monitoring and local experience. The Manual
shall describe the best management practices (BMPs) appropriate for
use in the City.
[Ord. No. 2695, Added, 2-16-2016]
1.
Project
Classification and Stormwater Management Minimum Requirements.
a.
The
development project shall use, to the maximum extent practicable,
site planning and design technique(s) that reduce post-development
runoff rates, volumes, and pollutant loads to match pre-development
conditions. Such techniques include, but are not limited to, minimization
of impervious surface, use of on-site retention to reduce the volume
and rate of runoff entering the stormwater management system, development
design that reduces the rate and volume of runoff from impervious
surfaces, and distributed stormwater management practices that intercept
and treat runoff from developed areas.
b.
When
low impact development and green infrastructure techniques are employed,
the design shall comply with the Manual, unless a project is specifically
exempted or excepted pursuant to subsections (2) and (3) of this section.
c.
Stormwater
shall be managed in as close proximity to the development site as
practicable. Stormwater management shall avoid a net negative impact
on nearby streams, wetlands, groundwater, and other water bodies.
All local, state, and federal permit requirements related to implementation
of stormwater management facilities must be met by the owner/operator
prior to facility use. Surface water discharges from on-site facilities
shall be discharged to an approved stormwater facility.
d.
All
stormwater management facilities shall meet the following requirements.
For purposes of determining applicability, all applications on a given
parcel or contiguous parcels under common ownership conducted within
a three-year period shall be considered cumulatively. All projects
subject to this Code shall submit to the City of Lake Oswego for review
and approval the reports and plans as provided herein.
i.
Small Projects (New Impervious Area Greater Than or Equal to 1,000
Square Feet; Less Than 3,000 Square Feet). All developments that create
new impervious area equal to or greater than 1,000 square feet and
less than 3,000 square feet shall meet the following minimum requirements:
A.
Site Assessment and Feasibility Analysis. Applicant shall submit
a site assessment and feasibility analysis. (See City Manager’s
additional submittal requirements, as indicated in the Manual.) The
applicant is encouraged to hold a pre-submittal consultation meeting
with the City Engineer to discuss potential approaches for stormwater
design and opportunities to use design techniques to reduce runoff
rates, volumes, and pollutant loads to pre-development conditions
to the maximum extent practicable. In addition, the applicant may
meet on-site with the City Engineer prior to approval of the stormwater
management drainage plan for the purposes of verifying the conditions
of the site and all receiving waterbodies.
B.
On-Site Stormwater Management. On-site stormwater management facilities
shall be sized to infiltrate 100 percent of the stormwater runoff
for a ten-year, 24-hour design storm based on location-and depth-specific
tested infiltration rates. Facility design shall be based on the Site
Assessment and Feasibility Analysis, as approved by the City Engineer.
C.
Erosion and Sediment Control. When development disturbs greater than 500 square feet or is within 50 feet of waters of the state, the project shall obtain an Erosion Control Permit [LOC Chapter 52]. An Erosion Control Permit is issued upon approval of an Erosion Control Plan. The baseline for the 50-foot measurement is the ordinary high water mark of a stream or the delineated boundary of a wetland or other water body pursuant to Department of State Lands requirements.
D.
Underground Injection Control (UIC) Review with DEQ. The applicant
shall demonstrate that any proposed UIC is rule authorized pursuant
to OAR 340-44-0018, or has either a DEQ-issued UIC permit associated
with the facility or has received a notice of intent to issue a UIC
permit. Stormwater shall not be discharged to a UIC that does not
meet the above requirements.
E.
Stormwater System Design. Applicant shall submit a stormwater system
design (including plans and specifications). (See the Manual for detailed
requirements.)
F.
Downstream Analysis Required. Applicant shall submit a downstream
analysis. (See Manual for detailed requirements.)
G.
Drainage Report Required.
(1)
Applicant shall submit a Drainage Report that quantifies and
describes all impervious surfaces on the site, including the identification
of Total Impervious Area (TIA) and Effective Impervious Areas (EIA),
for each proposed stormwater facility.
(2)
The applicant is encouraged to meet on-site with the City Engineer
prior to submittal of the Drainage Report for the purposes of verifying
the conditions of the site and all receiving waterbodies.
(3)
The City Engineer may require the applicant to submit a modified
Drainage Report if inspection or monitoring reveals that the actions
undertaken pursuant to an approved Drainage Report may result in the
actual discharge of or the potential to discharge a significant amount
of any pollutant as determined by the City. The City Engineer shall
notify the applicant that the Drainage Report is required to be modified.
The notice shall state the deadline for submission of the modified
Drainage Report, which shall be established by the City Engineer based
upon the severity of discharge of pollutant and the expected difficulty
of determining an alternative method of reducing the discharge to
the maximum extent practicable. The modified Drainage Report shall
be submitted for review and approval and the revisions implemented
prior to final acceptance of the facilities by the City.
H.
Operations and Maintenance Plan. An Operations and Maintenance Plan
must be prepared by the applicant and, following review and approval
by the City Engineer, recorded in the county in which the property/facility
is located.
I.
The applicant’s designer shall be responsible for all stormwater
system design, Site Assessment and Feasibility Analysis, Drainage
Report, Operations and Maintenance Plan, as applicable.
ii.
Large Projects (Impervious Area Greater Than or Equal to 3,000 Square
Feet). Projects that create new, redevelop (replace), or both create
and redevelop, impervious surface, where the sum total of affected
impervious surface area is equal to or greater than 3,000 square feet,
shall meet the following minimum requirements and controls.
A.
Requirements and controls applicable to small projects. Comply with
subsection (1)(d)(i) of this section.
B.
Water Quality. Stormwater management facilities shall be designed
to capture and treat 80% of the average annual runoff volume, based
on local rainfall frequency and intensity. (See Manual for design
storm information.)
C.
Flow Control. Stormwater management facilities shall be designed
to maintain postdevelopment peak flow rates at their pre-development
(c. 1850) levels for the two-year, five-year, and tenyear, 24-hour
runoff events.
D.
NPDES 1200-C Permit. Applicant shall obtain a DEQ Construction Stormwater
Permit (1200-C permit), when appropriate.
iii.
Maintenance Projects (Impervious Area Greater Than or Equal to 3,000
Square Feet) with Additional Hydrologic Impacts. Repair or maintenance
activities on structures or facilities with greater than or equal
to 3,000 square feet of existing impervious surface and that result
in additional off-site hydrologic impacts are subject to the requirements
for large projects in subsection (1)(d)(ii) of this section.
e.
All
Drainage Reports must address all criteria required for the report.
Incomplete reports will be returned to the applicant.
f.
Any
modification of a Drainage Report shall be submitted to the City Engineer
for review and approval. The report, as modified, must comply with
the requirements for the report.
g.
If
an UIC is located on a site that does not have DEQ UIC permit or is
not qualified for rule authorization under OAR 340-44-0018, and the
applicant cannot obtain a UIC permit, the existing UIC system shall
be decommissioned. Applicant shall follow DEQ’s guidelines for
decommissioning the UIC.
2.
Exemptions
from Certain Requirements. The following development and activities
are exempt from certain requirements of this article:
a.
Utilities.
Maintenance, repair, or installation of underground or overhead utility
facilities, e.g., pipes, conduits and vaults, that include replacing
the ground surface with in-kind material or materials with similar
runoff characteristics are exempt from flow control or water quality
treatment requirements.
b.
Road
Maintenance Activities. The following road maintenance activities,
conducted with consideration of pollution prevention practices, are
exempt from flow control or water quality treatment requirements:
c.
Sites
That Manage Stormwater On-Site Where New Development Produces No Runoff.
Developments that manage all stormwater on-site and produce no runoff
during the flow control design events, as determined by a civil engineer
registered in the State of Oregon and approved by the City Manager,
are exempt from flow control requirements.
d.
Right-of-Way.
Right-of-way under control of another government body where that governmental
body uses BMPs consistent with its own stormwater management program
and approved NPDES Stormwater Discharge Permit where applicable, provided
the BMPs are at least as stringent, as determined by the City Engineer,
as provided in the Manual, are exempt from flow control or water quality
treatment requirements.
3.
Exceptions.
a.
Grounds
for Exceptions. The City Engineer may approve exceptions to the requirements
of this Article when:
i.
The exception, as mitigated, will not increase risks in the vicinity
and downstream of the site to public health, safety and welfare, or
to water quality or quantity, or to public and private property; or
ii.
Where the requirement:
A.
Will cause harm or a significant threat of harm to public health,
safety and welfare, including water quality or quantity, or harm public
and private property;
B.
Is not technically feasible based on design requirements of the Lake
Oswego Stormwater Management Manual; or
C.
Cannot be met because an emergency exists, such as where there is
immediate danger of landslide, damage to public or private property,
or failure of a public facility, that necessitates approval of the
exception;
iii.
The exception is only to the extent necessary to alleviate the condition
in subsection (3)(a)(ii) of this section;
iv.
Mitigation in the form of off-site stormwater control or other means
may be required by the City Engineer.
b.
Conditions of Approval. When an exception is granted, conditions of approval may be imposed to offset or mitigate harm that may be caused by granting the exception, or that would have been prevented if the exception had not been granted. This may include off-site stormwater treatment or payment into a fee-inlieu program as allowed in LOC § 38.25.170(3).
c.
Exception
Procedure.
i.
Additional information may be required, e.g., an engineer’s
report or analysis, when necessary to demonstrate that the criteria
are met and the exception will not harm or result in a significant
threat of harm to public health, safety and welfare, to the environment,
or to public or private property.
ii.
Written findings of fact shall be issued with the decision.
[Ord. No. 2695, Added, 2-16-2016]
1.
Notice
of Construction Commencement.
a.
The
applicant shall obtain a Public Improvement Permit for public infrastructure.
b.
Prior
to the commencement of construction, the contractor shall arrange
for a pre-construction meeting with the City Engineer.
c.
The
applicant shall notify the City Engineer in advance of construction
of any components of the stormwater facilities on the approved Drainage
Report that are identified by the City Engineer as "critical" in the
construction permit. The City may, at its discretion, issue verbal
or written authorization to proceed with critical construction steps,
such as installation of permanent stormwater facilities.
2.
Construction
Inspection by City. A final inspection and signoff on completion by
the City is required before a Certificate of Acceptance will be provided.
3.
Inspection
and Certification by Stormwater Facility Designer. The stormwater
management facility designer shall inspect and certify to the City
Engineer that the facility has been constructed as designed, meets
functional requirements outlined in the Drainage Report, and can be
maintained in accordance with the Operations and Maintenance Plan.
[Ord. No. 2695, Added, 2-16-2016; Ord. No. 2890, Amended, 3-17-2022]
1.
Purpose.
This section requires periodic maintenance inspections and repairs
of stormwater facilities so that they will continue to function.
2.
Maintenance
Responsibility. The responsible party shall maintain stormwater facilities
in "good condition" as defined in the Operations and Maintenance Plan,
and shall:
a.
Inspect
the facilities as provided for in the Operations and Maintenance Plan,
or as necessary to assure the facility is in working order;
b.
Promptly
repair and restore stormwater management facilities;
c.
Maintain
the stormwater management facilities and their access routes to and
from the public right-of-way in accordance with the Manual, the approved
Drainage Report, and the Operations and Maintenance Plan.
3.
Requirements.
The maintenance requirements for all stormwater management facilities
are:
a.
Operations
and Maintenance Plan.
i.
The Operations and Maintenance Plan shall be reviewed and approved
by the City Engineer for all private stormwater management facilities.
ii.
This Plan shall contain any agreements regarding operations and maintenance
of stormwater facilities that are required as a condition of approval.
iii.
The approved Operations and Maintenance Plan shall be recorded as
a covenant against the property(s) obligated to operate and maintain
the stormwater management facilities with the appropriate county recording
officer on a legal instrument approved by the City Engineer, and shall
run with the land.
b.
All
repairs, restoration, and maintenance shall be in accordance with
the Manual, the approved Drainage Report, and the recorded Operations
and Maintenance Plan.
i.
Stormwater facility renovations, restoration, or replacements shall
be submitted to the Engineering Department for review and approval.
Submittals shall include all information required by the current Lake
Oswego Stormwater Management Manual.
ii.
Stormwater facility renovations, restorations, and replacements shall
conform with the current erosion and sediment control requirements.
iii.
Stormwater facility restorations must bring the failing stormwater
facility into compliance with the original approved plans or land
use requirements. The land use requirements will prevail if a conflict
exists between the approved plans and the land use requirements.
iv.
Stormwater facility renovations must bring the failing or failed
stormwater facility into compliance with the requirements of the current
Lake Oswego Stormwater Management Manual.
v.
Stormwater replacements must conform with the requirements of the
current Lake Oswego Stormwater Management Manual.
c.
Successors
and Assignees of the Property. The applicant and successor Responsible
Parties shall inform purchasers and other successors and assignees
of the property of the existence of private stormwater management
facilities on the site, the Drainage Report, the restrictions of the
stormwater management facilities (including design capacity, and related
easements, and the requirements for inspection and maintenance of
the stormwater facilities).
d.
Access by City. All stormwater management facilities, whether located on private or public property, shall be reasonably accessible for City inspection. The responsible party shall assure inspection access by easement to the City. See LOC § 38.25.160(1) for easement requirements. When stormwater management facilities are accepted by the City for maintenance, access easements shall be provided at a width sufficient to allow access by maintenance and inspection equipment, as outlined in the current version of the Manual.
e.
Private Facility Agreement with City. An agreement with the City shall be required when the private stormwater management facility will be operated or maintained by the City. The responsible party shall assure operation and maintenance access by easement to the City. See LOC § 38.25.160(1) for easement requirements.
f.
Transfer of Private Facilities to City. When ownership of stormwater management facilities is transferred to and accepted by the City, access easements shall be provided as described in subsection (c) of this section.
g.
Inspection
and Maintenance. The responsible party shall inspect and maintain
stormwater management facilities on a schedule that is stated in the
Operations and Maintenance Plan.
i.
Inspection and Maintenance Frequency. The applicant shall inspect
and maintain stormwater management facilities at a frequency sufficient
for the facility to operate at design capacity while in good working
order.
ii.
More Frequent Inspections/Maintenance. The City may require the applicant
to conduct more frequent inspections and/or perform maintenance more
frequently when necessary to reasonably ensure continuous working
order at design capacity, e.g., prior to full build-out of the facility
catchment, when nuisance conditions are present, or following severe
storm events.
h.
Maintenance
Inspection by City. The City Engineer shall establish inspection programs
to evaluate and enforce compliance with the requirements of this article,
which may include but are not limited to:
i.
Inspection
of Facilities Operating Under a Certificate of Acceptance. The City
Engineer shall cause or conduct periodic inspections for all stormwater
management facilities for which a Certificate of Acceptance (full
or partial) has been issued. All inspections shall be documented in
writing. The inspection shall document any maintenance and repair
needs and any discrepancies from the Operations and Maintenance Plan.
j.
Records
and Reporting of Maintenance Activities. The responsible party shall:
i.
Maintain and report to the City Engineer all records of maintenance
activities and facility repair as described in the Operations and
Maintenance Plan.
ii.
Report maintenance activities to the City Engineer on a schedule
consistent with the Manual, and with the facility’s approved
Drainage Report and Operations and Maintenance Plan.
iii.
Retain the records for at least ten years. These records shall be
made available to the City Engineer during inspection of the stormwater
management facility and at other reasonable times upon request.
iv.
The records shall be transferred to the successor responsible party
of the stormwater facility.
v.
The records may be retained by electronic means. The responsible
party shall provide duplicate copies of the retained records to the
City Engineer upon request.
4.
Failure to Provide Adequate Maintenance of Stormwater Management Facility. In the event the City Manager has reason to believe that the stormwater management facility has not been maintained pursuant to subsection (3)(g) of this section, or that it has become a threat to public safety, health and welfare, or water quality standards:
a.
The
City Manager shall notify the responsible party by certified mail
at the address shown on the most recent tax assessment roll. If the
responsible party is an entity, notice may also be given to an officer
of the entity or to its registered agent as shown by the records of
the Secretary of State. The notice shall specify the suspected nonmaintenance
or conditions giving rise to the violation, and the measures the City
Manager deems needed to comply.
i.
The notice shall specify a correction period of 30 days or a time
period established by the City Manager, as needed under the circumstances
to correct the violation. The City Manager may require the responsible
party to set forth a proposed plan of correction for review and approval.
In such case, the correction period would extend to the period set
forth in the plan of correction.
ii.
Within one-half of the correction period, the responsible party may
propose alternative methods to the City Manager to correct the violation.
If approved by the City Manager, the alternative methods shall be
carried out by the responsible party within the correction period.
b.
If
corrective measures are not completed within the correction period,
then the City Manager may pursue enforcement procedures pursuant to
this Article, or otherwise under the Lake Oswego Code.
c.
If
corrective measures are not completed and the stormwater facility
returned to operation as provided in the Operations and Maintenance
Plan within the correction period, the City Manager may correct a
violation by entering the property and performing the necessary work.
d.
The
City Manager may assess the responsible party for the cost of repair
work, which shall be the personal liability of the responsible party.
In addition, the City Manager may record a lien on the property in
the Municipal Lien Docket, and shall provide notice to the owners
of the liened property. The City Manager may undertake collection
against the responsible party personally, and may also undertake foreclosure
of the lien in the manner provided by Oregon law for foreclosure of
mortgages.
