Dunes City Chapter 99 Revised Stormwater Management Ordinance (Draft)
(Before the City Council, March 12, 2009)

Sections:

 99.05	Findings of Fact
99.10	Need
99.15	Purpose
99.20	Applicability
99.25	Financial Liability
99.30	Exemptions
99.35	Illicit Discharges
99.40	Abrogation and Greater Restrictions
99.45	Stormwater Best Management Practices (BMPs.
99.50	Stormwater Containment and Destination Standards
99.55	Pollution Reduction Standards
99.60	Flow Control Standards
99.65	Stormwater Source Controls
99.70	Stormwater Operations and Maintenance Standards
99.75	Inspection
99.80	Enforcement
99.85	Stop Work Order
99.90	Civil Penalty
99.95	Penalties Due
99.100 	Exceptions
99.105    Finding of Fact Exceptions
99.110	Prior Approval
99.115	Duration of Exceptionl
99.120	Right of Appeal
99.125	Adjustment Review-Approval Criteria
99.130	Stormwater Management Manual 
99.135	Definitions 

99.05 Findings of Fact.

The City Council of the City of Dunes City hereby finds that:

A. Stormwater pollution is a problem associated with land utilization and development and results in the common occurrence of potential pollutants such as pesticides, fertilizers, petroleum products, pet wastes, and numerous others.

B. Land utilization and development is also known to increase both the volume and duration of peak flows. The resulting erosion, scouring, and deposition of sediment affect the ecological balance in all water bodies.  

C. Sedimentation and stormwater pollution cause diversity of species to decrease and allows more tolerant (and usually less desirable) species to remain.

D. Stormwater pollution can cause or contribute to restrictions on public use of the waters within the city

E.  An expanding population and increased development of land have led to:

1.  Water quality degradation through discharge of nutrients, metals, oil and  grease, toxic materials, and other detrimental substances including, without limitation, insect and weed control compounds.
2.  Drainage and storm- and surface-water runoff problems within the city. 
3.  Safety hazards to both lives and property posed by uncontrolled water runoff on streets and highways.
F. Continuation of present stormwater management practices, to the extent that they exist, will lead to water quality degradation, erosion, property damage, and will endanger the health and safety of the inhabitants of Dunes City.
G.  In the future such problems and dangers will be reduced or avoided if existing properties and future developers, both private and public, provide for stormwater quality and quantity controls.

H.  Stormwater quality and quantity controls can be achieved when land is developed or redeveloped by implementing appropriate best management practices (BMPs).

 I.  Best management practices (BMPs) can be expected to perform as intended only when properly designed, constructed and maintained.

99.10 Need.

The city council finds that this chapter is necessary in order to:

A.  Fulfill Dunes City’s obligation to promote the public health, safety and general welfare of its citizens, as delegated to it by the Legislature of this State in ORS 221.410 and as defined in ORS 468.015 Policy.

B.  Fulfill Dunes City’s obligation to enact Zoning Ordinances and Regulations pertaining to the development of land as delegated to it by the Legislature of this State in ORS 227.010 seq.

C.  Fulfill Dunes City’s obligation to comply with Oregon’s Statewide Planning Goals and Guidelines as outlined in Goal 6: Air, Water and Land Resources Quality. 

D.  Implement Policies as outlined in the Dunes City Comprehensive Plan adopted by Dunes City in September, 1997:
1.   Policy B-9 (page 7).
2.   Policy E-7 (page 11) and,
3.   Chapter IV, Section B-2(a) (vi) (page 49).
 
E.  Minimize or eliminate water quality degradation.

F.  Prevent erosion and sedimentation in all water bodies.

G.  Protect property owners adjacent to existing and developing lands from increased runoff rates which could cause erosion of abutting property.

H.  Preserve and enhance the suitability of waters for contact recreation, fishing, and other beneficial uses.

I. Preserve and enhance the aesthetic quality of the water.

J.   Promote sound development policies which respect and preserve city surface water, ground water and sediment.

K.  Ensure the safety of city roads and rights-of-way.

L.  Decrease stormwater-related damage to public and private property from existing and future runoff.

99.15 Purpose.

The purpose of this chapter is to:

A.  Establish requirements and standards for protecting and safeguarding the general health and safety of the public by reducing stormwater-related impacts on the quality of the city’s water resources including drinking water.

B.  To provide for standards for the capture and treatment of stormwater run-off from impervious surface areas and to reduce the introduction of pollutants into stormwater.

C.  Minimize water quality degradation and sedimentation in streams, ponds, lakes, wetlands and other water bodies.
D.  Minimize the impact of increased runoff, erosion and sedimentation caused by land development and maintenance practices.
E. Maintain and protect surfacewater and groundwater resources.
F.  Minimize adverse impacts of alterations on ground and surface water quantities, locations and flow patterns.
G.  Decrease potential landslide, flood and erosion damage to public and private property.
H.  Promote site planning and construction practices that are consistent with natural topographical, vegetational and hydrological conditions.
I.  Maintain and protect any city stormwater management facility.
J.   Provide a means of regulating clearing, grading and development of private and public land while minimizing water quality impacts in order to protect public health and safety.
K.  Provide development regulations and construction procedures which will preserve, replace or enhance, to the maximum extent practicable, existing vegetation, uplands, wetlands and water bodies.
99.20 Applicability.

A. When any provision of any other chapter of the Dunes City Code conflicts with this chapter, that which provides more environmental protection shall apply unless specifically provided otherwise in this chapter. 

B. The improvement of both public and private stormwater management facilities through or adjacent to a new development shall be the responsibility of the developer. Said improvements shall comply with all applicable city ordinances, policies and standards.  Except as exempt under Chapter DCC 99.30, the standards in this chapter apply to all applications for development submitted after the effective date of this ordinance requesting approval of one or more of the following:

1.  Land use application: Partition tentative plan, subdivision tentative plan, planned unit development, tentative plan or site review.

2.  Development/Building Permit Application.
  
3.  Excavation, Grading, Driveway, or Access Permit Applications.

99.25 Financial Liability.

A.  A surety bond shall be required for all projects to ensure compliance with these standards. Bonds shall be set at 125 percent (%) of the estimated cost of all stormwater-related improvements and the cost of erosion/sedimentation control.

B.  In lieu of a surety bond, the applicant may file a cash bond or instrument of credit with the City Recorder in an amount equal to that which would be required in a surety bond.  Dunes City Ordinance 135 and Am. Ord. 150.

99.30  Exemptions.

The requirements and standards of this chapter do not apply to:
  
A.  An application that will result in the construction or creation of less than five-hundred square feet (500 sf) of new or replaced impervious surface area at full build out of the development.

B.  A development/building permit application for any of the following:
  
1.  Development of a lot or parcel included in a land use application that was determined by the city to comply with the standards in Chapter DCC 99.55, Pollution Reduction Standards.  The approved land use application shall control development. 
  
 	2.  Development of a lot or parcel that was not included in an application that was determined by the city to comply with the standards in Chapter DCC 99.55 and will result in less than five-hundred square feet (500 sf) of new or replaced impervious surface within a 12 month period.

 99.35 Illicit Discharges.

Illicit discharges to stormwater drainage systems are prohibited.  Subject to civil penalties, per Chapter DCC 99.90.

99.40	Abrogation and Greater Restrictions.

It is not intended that this chapter repeal, abrogate, or impair any existing regulations, easements, covenants, or deed restrictions. However, where this chapter imposes greater restrictions, the provisions of this chapter shall prevail.

99.45  Stormwater Best Management Practices (BMPs).

Best Management Practices shall be used to control pollution from stormwater. BMPs shall be used to comply with the standards in this chapter.  See Dunes City Stormwater Manual and Appendix  F: Oregon Department of Environmental Quality (DEQ) Erosion and Sediment Control Manual.

99.50  Stormwater Containment and Destination Standards.

  The purpose of these standards is to protect life, property and the natural environment from flood and drainage hazards through the establishment of containment and destination regulations for stormwater runoff from development.

 A.  Stormwater Containment and Destination requirements apply to all new development, except as exempted under Chapter DCC 99.30.

B.  No construction or site disturbance for any new development that requires a  DEQ NPDES 1200-C Construction Stormwater Permit may begin before applicant first obtains the permit and files a copy with the Dunes City Planning Department.  

C.  Construction or Site Disturbance for any parcel that does not require the 1200-C Construction Stormwater Permit, as a minimum, shall adhere to the following BMPs and be required to control erosion and sediment during construction, to permanently stabilize soil exposed during construction and to comply with site drainage requirements 1 through 5 as follows, unless exempted under Chapter DCC 99.30.

1.  Construction vehicle access shall be, whenever possible, limited to one route.  Access points shall be stabilized with quarry spall or crushed rock to minimize the tracking of sediment onto public roads. 

2.  All exposed soils shall be stabilized by suitable application of BMPs, including but not limited to sod or other vegetation, plastic covering, mulching, or application of ground base on areas to be paved. All BMPs shall be selected, designed and maintained in accordance with an approved manual. From October 1st through May 31st no soils shall remain exposed for more than two days. From June 1st  through September 30th, no soils shall remain exposed for more than seven days.

3.  Adjacent properties shall be protected from sediment deposition by appropriate use of vegetative buffer strips, sediment barriers or filters, dikes or mulching, or by a combination of these measures and other appropriate BMPs.

4.  All erosion and sediment control BMPs shall be regularly inspected and maintained to ensure continued performance of their intended function.
 
5.  As required by the manual, the Dunes City Council and the Health and Safety Inspector can implement other appropriate BMPs in order to mitigate  for an event that results in an unanticipated increase in runoff.  
 
D.  All Stormwater facilities shall be designed and constructed in accordance with the flood control design standards of this and the facility design requirements set forth in the Stormwater Management Manual.

E.  An applicant proposing new development must submit documentation to Dunes City showing stormwater runoff generated by the new development at the design storm level that will be either:

1.	Contained on-site in accordance with Chapter DCC 99 and/or the Stormwater Management Manual.   
2.	Discharged off-site in accordance with Chapter DCC 99 and/or the Stormwater Management Manual into an existing stormwater drainage facility that has the capacity to accommodate the runoff from the proposed development.  In demonstrating facility capacity, the evaluation shall include the runoff from all current uses to the stormwater facility and runoff from new development proposals that have already been approved by the City as of the date the applicant submits a complete application.  Prior approvals shall include, but are not limited to, tentative plans and final plats. Where off-site destination includes the direct discharge of runoff into any water body, the proposal must comply with the Flow Control requirements of Chapter DCC 99.60. 
3.	If the applicant cannot demonstrate that existing stormwater drainage facilities have adequate capacity to accommodate the proposed runoff from the new development, the applicant must construct storm drainage facilities with adequate capacity to accommodate the runoff from the proposed development, or construct on-site containment facilities per (#1) above.  
F. Stormwater runoff disposed of in underground systems may also be regulated through the federal Underground Injection Control (UIC) program under Part C of the Safe Drinking Water Act (42 U.S.C 300, 6A, Subchapter XII) and Oregon Administrative Rule Chapter 340, Section 044.

99.55 Pollution Reduction Standards. 

   	The purpose of this section is to protect public health by reducing the introduction of pollution into the waters of the city.
  
 A.  Land use and development applications shall include pollution reduction facilities selected from the Stormwater Management Manual as follows:
  
1.	For all land applications listed in Chapter DCC 99.50 B 1 and 3, the selected pollution reduction facilities shall treat all the stormwater runoff from the development site that will result from the design storm.  
 2.	For applications listed in Chapter DCC 99.50 B 1 and 3 that change the area of impervious surfaces, the selected pollution reduction facilities shall treat the stormwater runoff from the amended (added or subtracted) impervious surfaces that will result from the design storm.  
3.	For all Development/Building applications listed in Chapter DCC 99.50 B (2), applicants shall select pollution reduction facilities that treat all stormwater runoff from all new or replaced impervious surface area, or an equivalent on-site area, that will result from the design storm.   
B.  All pollution reduction facilities shall be sited, designed, constructed, and maintained according to the pollution reduction provisions and the facility design requirements set forth in the Stormwater Management Manual.
  
C.  The standards of this section may be adjusted pursuant to the Stormwater Management Manual and allow for the exceptions as indicated in Chapter DCC 99.30.

99.60 Flow Control Standards.  

The purpose of this section is to protect water bodies from the erosive effects of increases in stormwater runoff peak flow rates and volumes that result from the effects of impervious surfaces and land disturbances.
  
A.  All proposed improvements that may create stormwater flows which drain into a stream, pipe, or conduit shall demonstrate using methodology in the Stormwater Management Manual that peak rates of flow delivered to an existing water body will not increase during a design storm as a result of the proposed development.
  
B.  For purposes of designing the system as required by the standards in this section the amount of impervious surface per lot is assumed to be the maximum allowed lot coverage by structures plus all additional impervious surface coverage.
  
C.  All facilities to control the rate of stormwater runoff shall be sited, designed and constructed according to the flow control provisions and the facility design requirements set forth in the Stormwater Management Manual.  Flow control facilities must be designed using one of the methodologies outlined in the Stormwater Management Manual.
  
D.	The standards in this section may be adjusted pursuant to the Stormwater Management Manual.

99.65	Stormwater Source Controls.

All source controls shall be designed and constructed according to the source control provisions set forth in the Stormwater Management Manual, except when the source control would duplicate controls required by a state or federal permit, (i.e. DEQ 1200-C Permit) obtained by the applicant.  Following are some examples of areas where stormwater source controls are mandated.
    
A.  Fuel dispensing facilities and surrounding traffic areas where vehicles, equipment or tanks are refueled on the premises.  A fuel dispensing facility is the area where fuel is transferred from bulk storage tanks to vehicles, equipment, and/or mobile containers.  Exempt from these controls are propane tanks.
  
B.  Exterior storage of liquid materials, for example chemicals, food products, waste oils, solvents or petroleum products in above ground containers, in quantities of fifty gallons or more, including permanent and temporary storage areas.  Exempt from this subsection are underground storage tanks or installations requiring a Water Pollution Control Facility (WPCF) permit and containers with internal protections.
  
C.  All facilities that store solid waste.  A solid waste storage area is a place where solid waste containers, including compactors, dumpsters, and garbage cans, are collectively stored.  Solid waste storage areas include areas used to collect and store refuse or recyclable materials collection areas.
  
D.  All development that stockpiles or stores high-risk or low-risk bulk materials in outdoor containers, as the terms “high-risk” and “low-risk” are used in the Stormwater Management Manual.  Exempt from this subsection are:
  
1.  Materials that have no measurable solubility or mobility in water and no hazardous, toxic or flammable properties.  
2.	Materials that exist in gaseous form at ambient temperature.  
3.	Materials, except for pesticides and fertilizers, which are contained in a manner that prevents contact with stormwater.  
E.  All development with a designated equipment or vehicle washing or steam cleaning area.
  
F.  All development projects that disturb property suspected or known to contain contaminants in the soil or groundwater.

99.70  Stormwater Operations and Maintenance Standards. 

The purpose of this section is to ensure that through adequate operation and maintenance, stormwater facilities protect life and property from flood and drainage hazards and provide protection for water bodies and the natural environment from the erosive effects of runoff.
 
 A.   Operation and maintenance standards apply to all facilities designed and constructed in accordance with this Section and the Stormwater Management Manual.
  
B.  Unless otherwise agreed, stormwater management facilities shall be privately owned and shall be operated and maintained in accordance with this Chapter and the Stormwater Management Manual.
  
C.  The city shall maintain public stormwater management facilities located on city-owned property, city rights-of-way and city easements.
  
D.  To ensure that any city maintained stormwater management facility can be accessed by the city for routine and/or emergency maintenance the applicant of an applicable land use request or development permit must dedicate easements approved by and to the city.

E.  If Dunes City determines that maintenance or repair work is required to be done to stormwater management facilities located in the development, the city shall give the owner notice of the specific maintenance and/or repair required.  The city shall set a reasonable time in which such work is to be completed by the persons who were given notice. If the above required maintenance and/or repair is not completed within the time set by the city, written notice will be sent to the owner stating that the city’s intention is to perform such maintenance and bill the owner for all incurred expenses.
 	  
99.75	Inspection.  

A.  The City Council shall designate a Health and Safety Inspector qualified in stormwater control measures with responsibility for evaluating proposed and completed stormwater measures and facilities. The Inspector shall inspect projects at various stages of the work requiring approval to determine that adequate control is being exercised.  Stages of work requiring inspection include, but are not limited to; preconstruction, installation of BMPs, land disturbing activities, installation of utilities, landscaping, retaining walls and completion of project as specified in the Stormwater Management Manual.  When required by the inspector, a special inspection and/or testing shall be performed. The Inspector shall report to the City Council on the implementation of the requirements of this Chapter.    
 
B.  Inspections may include but are not limited to: routine inspections, random inspections, inspections based upon complaints or other notice of possible violations, inspections of drainage basins or areas identified as higher than typical sources of sediment or other contaminants or pollutants, or inspections of land uses that are of a type associated with higher than usual discharges of contaminants or pollutants.  In addition, inspections may include but are not limited to: reviewing maintenance and repair records, sampling discharges, surface water, groundwater, and material or water in drainage control facilities, and evaluating the condition of drainage control facilities and other stormwater treatment practices.

C.  When any new stormwater management facility is installed on private property, or when any new connection is made between private property and a public drainage control system, the property owner shall grant Dunes City the right to enter the property at reasonable times and in a reasonable manner for the purpose of inspection, abatement of a public nuisance or correction or investigation of a violation of this Chapter.

D.  Should entry be refused, the Health and Safety Inspector shall have recourse to the remedies provided by law to secure entry. (Dunes City Ordinance 150).

	E.   Liability for Health and Safety Inspector will be the same as that designated under Chapter DCC 151 §151.078.

99.80	Enforcement.

A.  Failure to construct, operate and maintain source controls as set forth in this Chapter shall be unlawful and a civil infraction subject to the enforcement provisions of Chapter DCC 36. 

 B.  If, at any time Dunes City determines that the existing facility creates any imminent threat to public health, safety, or welfare, Dunes City may take immediate measures to remedy said threat. No notice to the responsible party shall be required under such circumstances.  All other owner responsibilities will remain in effect.  And any  costs that are incurred by the City to correct this imminent threat, will be charged to the owner of the responsible facility. 

C.  The choice of enforcement action and the severity of any penalty shall be based on Chapter DCC 177 §1-B.

99.85	Stop work order.

The Health and Safety Inspector shall have the authority to serve a person a stop work order if an action is being undertaken in violation of this Chapter. If a portion of a project is in violation of this Chapter, the inspector may issue a stop work order for the entire project.

A.  The order shall contain:

1.  A description of the specific nature, extent and time of violation, and the damage or potential damage. 

2.  A notice that the violation or the potential violation must cease and desist, and, in appropriate cases, the specific corrective action to be taken within a given time. A civil penalty under Chapter DCC 36 and Chapter DCC 10.99 may be issued with the order.

B.  Notice.  A stop work order shall be imposed by a notice in writing, either by certified mail with return receipt requested, or by personal service, to the person incurring the same or by being posted on the work site. The certified mailing will be sent to the responsible party’s address on file with the City.  

C. Effective Date. The stop work order issued under this Chapter shall become effective immediately upon receipt by the person to whom the order is directed or within five (5) days of the mailing of the certified notice or when posted on the work site.

D. Compliance. Failure to comply with the terms of a stop work order shall result in enforcement actions including, but not limited to the issuance of a civil penalty pursuant to Chapter DCC 36.

	E.   Final approval shall not be granted until corrections to all stormwater improvements have been made and accepted by Dunes City.

F.  A Stop Work Order Hearing may be held pursuant to Chapter DCC 155.1.4.8 (B).	

99.90 Civil penalty.

A person who fails to comply with the requirements of this Chapter, who fails to conform to the terms of an approval or order issued, who undertakes new development without first obtaining city approval, or who fails to comply with a stop work order issued under these regulations shall be subject to a civil penalty pursuant to Chapter DCC 36.

A.   Amount of Penalty. The minimum penalty shall be $500.00 and the maximum penalty $2,500 for each violation as determined by the Health and Safety Inspector and/or the City Council. Each day of continued violation or repeated violation shall constitute a separate violation.  Fines will be consistent with those contained in Chapter DCC General Provisions; §10.99 and Chapter DCC 36 §36.14.

B.   Aiding or Abetting.  Any person who, through an act of commission or omission, aids or abets in the violation shall be considered to have committed a violation for the purposes of the civil penalty.

C.   Fine Imposition.  Reference:  Chapter DCC 36 §36.12.  
D.   Appeals:  Reference:  Chapter DCC 36 §36.13.

99.95 Penalties Due.

Penalties for violations of this chapter shall become due and payable 10 days after receipt of written notice of the violation, unless an appeal is filed pursuant to Chapter DCC 36 § 36.13.  Failure to pay such fine, shall constitute a violation against the city and subject to a civil penalty as provided in Chapter 36 § 36.99. 

99.100 Exceptions.

After a public hearing, the city council may grant an exception from the requirements of this Chapter.  In granting any exception, the city council may prescribe conditions that are deemed necessary or desirable for the public interest.

99.105 Finding of Fact (Exceptions).

Exceptions to the minimum requirements of stormwater source control (Chapter 99.65) may be granted prior to permit approval and construction. An exception may be granted following a public hearing, provided that a written finding of fact is prepared, that addresses the following:

A.  The exception provides equivalent environmental protection and is in the overriding public interest, and that the objectives of safety, function, environmental protection and facility maintenance, based upon sound engineering, are fully met.

B.  That there are special physical circumstances or conditions affecting the property such that the strict application of these provisions would deprive the applicant of all reasonable use of the parcel of land in question, and every effort to find creative ways to meet the intent of the minimum standards has been made.

C.  That the granting of the exception will not be detrimental to the public health and welfare, nor injurious to other properties in the vicinity and/or downstream, and to the quality of waters of the state.

D.  The exception is the least possible exception that could be granted to comply with the intent of the minimum requirements.

99.110	 Prior Approval.

Any exception shall be approved prior to permit approval and construction.

99.115 Duration of Exception.

Exceptions granted shall be valid for two years, unless granted for a shorter period.

99.120 Right of Appeal.

All actions of the city council, except those involving a civil penalty (Chapter DCC 36 §36.13), shall be final and conclusive, unless within 10 days of the date of the city council’s action, the original applicant or an adverse party gives written notice of appeal to the Superior Court of Lane County for review of the action.  

99.125 Adjustment Review – Approval Criteria. 

The Health and Safety Inspector shall approve, conditionally approve, or deny an adjustment review application for Stormwater Containment and Destination, Pollution Reduction, Flow Control and Source Control Standards.  Approval or conditional approval shall be based on compliance with the following applicable criteria.
  
 A.  The requirement in Chapter DCC 99-55 A 1 through 3; that selected pollution reduction facilities shall treat all the stormwater runoff that will result from a design storm may be adjusted upon a finding that the selected pollution reduction facility will treat as much of the runoff as possible and one of the following applies:
  
1.  The area generating untreated runoff is less than five-hundred square feet (500 sf) of impervious surface and is isolated from the pollution reduction facility.
  
2.  The area generating untreated runoff is less than five-hundred square feet (500 sf) of impervious surface and it is not technically feasible to drain the untreated runoff to the pollution reduction facility. 
 
3.  The area generating runoff is less than five-hundred square feet (500 sf) and constructing pollution reduction facilities to treat the runoff from the area at issue would require removal of trees or damage to other natural resources.
  
 4.  The area generating untreated runoff is less than five-hundred square feet (500 sf) of impervious surface and limited access to the area would prevent regular maintenance of the pollution reduction facility. 
 
B.  The requirement in Chapter DCC 99.55 B that all pollution reduction facilities be sited, designed and constructed according to the pollution reduction provisions and the facility design requirements set forth in the Stormwater Management Manual may be adjusted.  This adjustment shall be based upon findings that all of the following requirements are met:
  
1.  The proposed alternative design will achieve equal or superior results for pollution reduction function, maintainability and safety and the proposed site location does not adversely affect structures or other properties.
  
2.  The applicant’s written description of the proposed alternative design has been reviewed and approved by the Health and Safety Inspector and City Engineer. The description of the proposed design submitted for review must include all of the following information for each component of the proposed alternative design:
  
(a)  Size, technical description, capacity, capital cost, design life, construction process and costs, consequences of improper construction, operation and maintenance requirements and costs.  
(b)  Data on the effectiveness of proposed alternative technologies, if available, including data from laboratory testing and pilot/full-scale operations, and information regarding the operations of any full-scale installations.  
(c)  Any other available information about the proposed design, including peer reviewed articles, scientific or engineering journals, and approvals from other jurisdictions.  
3.  The applicant has submitted a method and schedule for monitoring the effectiveness of the proposed design once constructed and a schedule for its maintenance.  
4.  The applicant has submitted a signed statement that the applicant will replace the alternative pollution reduction facility if it does not function as proposed.  The applicant will be required to post a surety bond as per section Chapter DCC 99.25.
C.  The requirements in Chapter DCC 99.60 that Flow Control Standards and Chapter DCC 99.65 Source Control Standards be sited, designed and constructed according to the provisions and the facility design requirements as set forth in the Stormwater Management Manual.  Any adjustment will only be made if the applicant can demonstrate that the selected flow control facility will achieve the same result or a better result as those listed in the Stormwater Management Manual. 
   
99.130 Stormwater Management Manual.

In order to implement Chapter DCC 99.05 through 99.135, the City Council shall adopt a Stormwater Management Manual that is consistent with the following goals:

A.  Reduce runoff pollution from development by reducing the overall amount of impervious surface area and extent of connectedness to downstream drainages.

B.  Emphasize stormwater management facilities that, to the maximum extent practicable, retain and treat stormwater utilizing on-site controls.

C.  Emphasize stormwater management facilities that incorporate vegetation as a key element and include design and construction requirements that ensure landscape plant survival and overall stormwater facility function success.

D.  Operate and maintain stormwater management facilities in accordance with facility-specific Operation and Maintenance Plans.

E.  Reduce pollutants of concern that are generated by identified site uses and site characteristics that are not addressed solely through the pollution reduction measure by implementing additional specific source control methods including reducing or eliminating pathways that may introduce pollutants into stormwater and avoiding preventable discharges to surface waters or groundwater.

F.  The Stormwater Management Manual includes a list of scientifically accepted stormwater treatment practices, including the specific design criteria for each stormwater practice.  The manual may be updated and expanded from time to time, at the discretion of the City of Dunes City, based on improvements in engineering, science, monitoring and local maintenance experience.

99.135 Definitions.

For the purposes of this chapter, the following definitions shall apply:

“Approval”  The proposed work or completed work conforms to this chapter in the opinion of the director.

“Best management practices” or “BMPs”   Physical, structural, and/or managerial practices that, when used singly or in combination, prevent or reduce pollution of water. BMPs are listed and described in the stormwater manual.

“Clearing”  The destruction and removal of vegetation by manual, mechanical, or chemical methods.

“Comprehensive Plan”   The Dunes City plan to control and promote development which is most desirable to the majority of the residents and property owners of the City.  The Plan establishes a set of policies and guidelines which would allow for development to occur while preserving those qualities which brought them to the community or has made the community what it is today.

“Design storm”   A prescribed hyetograph (see description) and total precipitation amount (for a specific duration recurrence frequency) used to estimate runoff for a hypothetical storm of interest or concern for the purposes of analyzing existing drainage, designing new drainage facilities or assessing other impacts of a proposed project on the flow of surface water.  A hyetograph is a graph of percentages of total precipitation for a series of time steps representing the total time during which the precipitation occurs.

“Detention”  The release of stormwater runoff from the site at a slower rate than it is collected by the stormwater facility system, the difference being held in temporary storage.

“Detention facility”   An above or below ground facility, such as a pond or tank, that temporarily stores stormwater runoff and subsequently releases it at a slower rate than it is collected by the drainage facility system.  There is little or no filtering of stored stormwater.

“Development”   All improvements on a site, including buildings, other structures, parking and loading areas, landscaping, paved or graveled areas, grading and areas devoted to exterior display, storage, or activities.  Development includes improved open areas such as plazas and walkways, but does not include natural geologic forms or landscapes.

“Drainage basin”   A geographic and hydrologic subunit of a watershed.

“Erosion”  The wearing away of the land surface by running water, wind, ice, or other geological agents, including such processes as gravitational creep. “Erosion” also means the detachment and movement of soil or rock fragments by water, wind, ice, or gravity.

“Excavation”   The mechanical removal of earth material.
 
“Existing site conditions” 

1.  For developed sites with stormwater facilities that have been constructed to meet the standards in the minimum requirements of the manual, existing site conditions shall mean the existing conditions on the site.

2.  For developed sites that do not have stormwater facilities that meet the minimum requirements, existing site conditions shall mean the conditions that existed prior to local government adoption of a stormwater management program.  If in question, the existing site conditions shall be documented by aerial photograph records or other appropriate means.

3.	For all undeveloped sites, existing site conditions shall mean the existing conditions on the site.

“Flow Control Facility”   Any structure or drainage device that is designed, constructed, and maintained to collect, retain, infiltrate, or detain surface water runoff during and after a storm event for the purpose of controlling flow rate and volume leaving the site.

“Groundwater”  Water in a saturated zone or stratum beneath the surface of land or a surface water body.

“Hyetograph”   A graphical representation of the distribution of rainfall over the total duration of a storm event. For example, in the 24-hour rainfall distributions as developed by the Soil Conservation Service (now the NRCS or National Resources Conservation Service), rainfall intensity progressively increases until it reaches a maximum and then gradually decreases. Where this maximum occurs and how fast the maximum is reached is what differentiates one distribution from another. One important aspect to understand is that the distributions are for design storms.  Design storms are theoretical storms (not necessarily actual storms). In other words, a real storm may not behave in this same fashion. The maximum intensity may not be reached as uniformly as shown in the SCS hyetographs.
“Illicit Discharge”   All non-stormwater discharges to stormwater drainage systems that cause or contribute to a violation of state water quality, sediment quality or ground water quality standards, including but not limited to septic system affluent, industrial process water, interior floor drains, car washing and greywater systems.

“Impervious Surface”   A surface area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development, and/or a surface area which causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas (gravel or paved), concrete or asphalt paving, gravel roads or driveways, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces. Note:  Slatted decks are considered pervious surfaces. Gravel surfaces are considered pervious surfaces unless they cover impervious surfaces or are compacted to a degree that causes their run-off coefficient to exceed eighty percent (80%). 

“Mitigation”  In the following order of preference:

1.  Avoiding the impact altogether by not taking a certain action or part of an action.

2.  Minimizing impacts by limiting the degree or magnitude of the action and its implementation, by using appropriate technology, or by taking affirmative steps to avoid or reduce impacts.

3.  Rectifying the impact by repairing, rehabilitating or restoring the affected environment.

4.  Reducing or eliminating the impact over time by preservation and maintenance operations during the life of the action. 

5.  Compensation for the impact by replacing, enhancing, or providing
substitute resources or environments.

Nonpoint Source Pollution”   Discharge from a diffuse pollution source that is without a single point of origin.

“New Development”   The following activities: land disturbing activities, structural development, including construction, installation or expansion of a building or other structure, creation of impervious surfaces and Class IV-general forest practices that are conversions from timber land to other uses and subdivision of land.   All other forest practices and commercial agriculture are not considered new development.

“Person”   Any individual, partnership, corporation, association, organization, cooperative, public or municipal corporation, agency of the state, or local government unit, however designated.

“Pollution”   Contamination or other alteration of the physical, chemical, or biological properties of waters of the state, including change in temperature, taste, color, turbidity, or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the State as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare, or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish or other aquatic life.

“Pollution Reduction Facility”   Any structure or drainage device that is designed, constructed, and maintained to collect and filter, retain, or detain surface water runoff during and after a storm event for the purpose of maintaining or improving surface and/or groundwater quality. 
 
“Property suspected or known to contain contaminants in the soil or groundwater”   Any real property where the presence of any hazardous substance or petroleum product indicates an existing release, past release, or threatened release of a hazardous substance or petroleum product into the ground, groundwater, or surface water of the property

“Redevelopment”   On an already developed site, the creation or addition of impervious surfaces, structural development including construction, installation or expansion of a building or other structure, and/or replacement of an impervious surface that is not part of a routine maintenance activity and land disturbing activities associated with structural or impervious redevelopment.

“Runoff”   Water from rainfall, snow melt, or otherwise discharged that flows across the ground surface instead of infiltrating the ground.
  
“Site”  The portion of a piece of property that is directly subject to development.

“Soil”   The unconsolidated mineral and organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.

"Source Control”   Any structure, device, or design that is used to eliminate or reduce stormwater pollution from a known source. 

“Stormwater”   That portion of precipitation that does not naturally percolate into the ground or evaporate and is discharged from a surface, including, but not limited to, flows into defined surface water channels, water bodies, pipes or constructed infiltration facilities. 

 “Stormwater drainage system”   Describes constructed and natural features which function together as a system to collect, convey, channel, hold, inhibit, retain, detain, infiltrate, divert, treat or filter stormwater.

“Stormwater Management Manual”   The most recent version of the Dunes City Stormwater Management Manual as adopted by the city. 
 
“Stormwater Management Facility”    Any structure or configuration of the ground that is used or, by its location, becomes a place where stormwater flows or is accumulated, including but not limited to pipes, curbs, gutters, catch basins, ponds, open drainage ways, runoff control facilities, wetlands and their accessories.

“Water body”   All surface waters including rivers, streams, lakes, marine waters, estuaries, and wetlands.

“Watershed”   A geographic region within which water drains into a particular river, stream, or body of water.

“Vegetation”   All organic plant life growing on the surface of the earth.