[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.
