As used in this chapter, except where the context otherwise requires:
"Dwelling unit" (DU)
means one or more rooms with bathroom and kitchen facilities designed for occupancy by one family such as detached, townhouses, condominiums, zero lot-line, etc., where the units are sold and deeded as single-family units.
"Multiple dwelling unit" (MDU)
means a building or facility consisting of more than one dwelling unit, each such unit consisting of one or more rooms with bathroom and kitchen facilities designed for occupancy by one family.
"Mobile home court"
means two or more spaces on the same parcel and occupied by mobile homes.
"Commercial unit"
means any building or facility used other than as a dwelling unit or for industrial purposes and which has not been converted to equivalent dwelling units.
"Equivalent Service Unit" (ESU)
means a residential or nonresidential configuration estimated to place approximate equal demand on the City's storm drainage system as a single family dwelling unit. One ESU shall be equal to twenty-five hundred square feet of impervious surface.
"Open drainageway"
means a natural or man-made path which has the specific function of transmitting natural stream water or storm runoff water from a point of higher elevation to a point of lower elevation.
"Impervious surfaces"
are those hard surface areas located upon real property which either prevent or retard saturation of water into the land surface, as existed under natural conditions pre-existent to development, or cause water to run off the land surface in greater quantities or at an increased rate of flow from that present under natural conditions pre-existent to development. Common impervious surfaces include, but are not limited to, rooftops, concrete or asphalt sidewalks, walkways, patio areas, driveways, parking lots or storage areas and graveled, oiled, macadam or other surfaces which similarly impact the natural saturation or runoff patterns which existed prior to development.
"Improved premises"
means any area which has been altered such that the runoff from the site is greater than that which could historically have been expected. Such a condition shall be determined by the City Engineer.
(Ord. 82-71 §1; Ord. 83-21 §1)
Pursuant to the general laws of the state of Oregon and the powers granted in the Charter of the City of Tigard, the Council of said City does declare its intention to acquire, own, construct, equip, operate and maintain within and without the city limits of the City of Tigard, Oregon, open drainageways, underground storm drains, equipment and appurtenances necessary, useful or convenient for a complete storm drainage system; and also including maintenance, extension and reconstruction of the present storm drainage system of the City.
(Ord. 82-71 §2)
There is established and imposed upon all premises which have been improved within the City of Tigard just and equitable charges for storm drainage service or subsequent service maintenance, operation and extension; and to establish a storm drainage proprietary fund for the foregoing purposes.
(Ord. 82-71 §3; Ord. 83-35 §2)
The charges may be collected with the monthly sanitary sewer bill for those connected to sewer or billed alone as storm drainage charge for those users not connected to or not otherwise charged for sanitary sewer.
(Ord. 82-71 §4)
Such charges shall be paid by those liable therefor and placed in a storm drainage fund into which all of the charges so collected shall be deposited and kept as a fund to be used only for the purposes aforesaid.
(Ord. 82-71 §5)
The City Council determines that property not used for single-family dwelling purposes is furnished service in proportion to the amount of the property's impervious surface, and that an equivalent service unit is adopted based upon the average impervious surface of a random sample of single-family lots within the Tigard area.
(Ord. 82-71 §6)
The City shall develop and adopt policies, standards, and financial incentives to promote, regulate and administer the City's Master Drainage Plan. The Council shall provide, by resolution, for a method of expenditure of funds collected pursuant to Section 3.36.030 of this chapter so that those service charge funds are expended in proportion to an areas contribution to storm drainage requirements.
(Ord. 82-71 §8)
Subject to constitutional limitations, the employees of the City shall at all reasonable times have access to any premises served by the City for inspection, repair or the enforcement of the provisions of this chapter.
(Ord. 82-71 §11)
1. 
As provided in ORS 454.225, when storm drainage charges are not paid when due, the amounts thereof together with interest at the statutory rate from the due date shall be certified to the assessor of the appropriate county for collection.
2. 
The liability for all accounts billed for storm drainage only shall be that of the owner of the property.
3. 
The City Recorder shall take any action necessary, under appropriate statutes, to enforce delinquent storm drainage charges as a lien against the property.
4. 
The charge for fifteen days or less of service upon new account or upon the closing of an account shall be one-half the applicable monthly charge.
(Ord. 82-71 §13)