Chapter 13.06
STORMWATER MANAGEMENT UTILITY – REGULATIONS AND RATES

Sections:

13.06.005    Purpose.

13.06.010    Definitions.

13.06.020    Stormwater management utility created.

13.06.030    Rate policy.

13.06.040    Measurement of impervious surface.

13.06.050    Undeveloped real property.

13.06.060    Creation of impervious surface.

13.06.070    Service charge rates.

13.06.080    Property exempt from service charges.

13.06.090    Collection of charges.

13.06.110    Authority to promulgate regulations.

13.06.005 Purpose.

A stormwater management utility is herein created and stormwater charges are herein imposed in order to protect the health, safety, and welfare of the public; collect, convey, manage, and mitigate the quantity and quality of stormwater runoff; mitigate flooding; prevent erosion; and meet the regulatory requirements of the National Pollutant Discharge Elimination System municipal stormwater permit, Clean Water Act, Clean Air Act, Endangered Species Act, and the city of Walla Walla’s Shoreline Master Program. (Ord. 2019-18 § 7, 2019).

13.06.010 Definitions.

Throughout this chapter the following words shall have the following meanings unless the context clearly indicates otherwise:

A. The “city” shall mean the city of Walla Walla, Washington, a municipal corporation created and existing under the laws of the state of Washington.

B. “Developed” shall mean that condition of real property altered from its natural state by the addition to or construction on such property of manmade physical improvements such that the hydrology of the property is affected. Developed property may or may not contain building structures.

C. An “equivalent residential unit” or “ERU” is the measure of impervious surface to be used by the utility in assessing service charges against each parcel of property.

D. “Impervious surface” shall mean a hard surfaced area which either prevents or retards the entry of water into the soil mantle as under natural conditions prior to development. A hard 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, rooftops, walkways, patios, driveways, parking lots, storage areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater.

E. “Low income citizen” refers to a person who meets the criteria established in Chapter 2.102.

F. “Service charge” means the monthly fee levied by the utility upon all developed real property within the boundaries of the utility as authorized in this chapter.

G. The “municipal stormwater drainage system” means a stormwater drainage system owned by the utility or over which the utility has control. (Synonymous with “MS4” as defined in the city of Walla Walla’s NPDES Phase II Permit.)

H. “Stormwater drainage system” means public or privately owned facilities which function together as a system to collect, convey, channel, retain, detain, infiltrate, divert, treat, or filter stormwater. This includes, but is not limited to, any roads and streets with curbs and gutters, storm drain inlets, piped storm drains, and stormwater BMPs/facilities.

I. “Stormwater BMP/facility” means any component of a stormwater drainage system that provides one or more of the following functions: collection, conveyance, retention, detention, infiltration, diversion, treatment, or filtration of stormwater. Stormwater BMPs/facilities include, but are not limited to, pipes, swales, ditches, culverts, street gutters, detention ponds, retention ponds, constructed wetlands, infiltration devices, catch basins, oil/water separators, biofiltration swales, underground injection control (UIC) wells, street trees, bioretention, and permeable pavement.

J. “Street tree” has the same meaning as defined in Section 12.49.010.

K. “Underground injection control (UIC) wells” means UIC wells as defined in the Stormwater Management Manual for Eastern Washington.

L. “Undeveloped” shall mean that condition of real property unaltered by the actions, construction, or addition to such property by man of impervious surface or physical manmade improvements or conditions of any kind which change the hydrology of the property or its soil from its natural state.

M. The “utility” means the city of Walla Walla, Washington, stormwater management utility, which includes all property within the Walla Walla city limits, as it now exists or is hereafter changed, within its boundaries.

N. For the purposes of the application of charges a duplex shall consist of two dwelling units on a single parcel whether adjoining or separated, a triplex shall consist of three dwelling units on a single parcel whether adjoining or separated, and a quadriplex shall consist of four dwelling units on a single parcel whether adjoining or separated. (Ord. 2019-24 § 1, 2019: Ord. 2019-18 § 8, 2019: Ord. 2017-45 § 28, 2017: Ord. 2015-30 § 17, 2015: Ord. 99-32 § 1(part), 1999).

13.06.020 Stormwater management utility created.

A city of Walla Walla stormwater management utility is created.

A. Property Transferred to Utility. All properties, interest, physical and intangible rights of every kind or nature owned or held by the city, however acquired, insofar as they relate to or concern the drainage, control, storage, treatment or disposal of storm or surface water sewerage, further including without limitation, all such properties, interest and rights acquired by adverse possession or by prescription, directly or through another, in and to the drainage or storage, or disposal, of storm or surface waters, or both, through, under or over lands, land forms, watercourses, sloughs, wetlands, streams, ponds, rivers, lakes and swamps, all beginning, in each case or instance, at a point where storm or surface waters first enter the storm or surface water system of the city and ending in each case or instance at a point where each storm or surface water exits from the storm or surface water system of the city, and in width to the full extent of inundation caused by storm or flood conditions, are transferred to and subject to the administration of the stormwater management utility as created by the chapter, and all other institutions and departments of the city having primary responsibility therefor within the city are, to the same extent, released from such primary responsibility.

B. Responsibility. The utility will have primary authority and responsibility for carrying out the city’s comprehensive stormwater management plan, including responsibilities for planning, design, construction, maintenance, administration, and operation of all city stormwater BMPs/facilities, as well as establishing standards for design, construction and maintenance of improvements on private property where these may impact storm and surface water and management.

C. Administrator of Utility. The Walla Walla city manager shall be the administrator of the utility. (Ord. 2019-18 § 9, 2019: Ord. 99-32 § 1(part), 1999).

13.06.030 Rate policy.

It shall be the policy of the city that the rate structure to be applied in establishing the amount of service charges assessed against each parcel of developed real property within the boundaries of the utility shall be based upon the amount of impervious surface contained within each parcel of property as measured by Section 13.06.040, except for those properties set forth in Section 13.06.080. All revenues generated by the rates shall be deposited in the stormwater management utility fund. (Ord. 2017-45 § 29, 2017: Ord. 2015-30 § 18, 2015: Ord. 99-32 § 1(part), 1999).

13.06.040 Measurement of impervious surface.

The utility shall measure the impervious surface of each parcel of developed real property within the boundaries of the utility to determine the number of equivalent residential units contained therein; three thousand square feet of impervious surface shall equal one ERU. All parcels developed as single-family residences are deemed to contain one ERU. The rates for multifamily residences with four or fewer units are defined in Section 13.06.070. For all other developed real properties within the utility boundaries (including manufactured housing parks without individual lot ownerships), the utility shall determine the number of equivalent residential units contained thereon by dividing the number of square feet of impervious surface on each property by three thousand; the total thus obtained will be rounded to the nearest whole number representing the equivalent residential units contained on such property. Each developed parcel of property shall be deemed to contain at least a minimum of one ERU. (Ord. 2019-33 § 1, 2019: Ord. 2017-45 § 30, 2017: Ord. 99-32 § 1(part), 1999).

13.06.050 Undeveloped real property.

In accordance with the policy established in Section 13.06.030 that the service charges be determined by the amount of impervious surface contained on each parcel of real property, those properties remaining in an undeveloped condition are deemed not to make use of the services of the utility or of the facilities of the system beyond that used by such property in the natural state. Therefore, no service charge shall be imposed upon that real property within the boundaries of the utility which is undeveloped. (Ord. 2017-45 § 31, 2017: Ord. 99-32 § 1(part), 1999).

13.06.060 Creation of impervious surface.

Developments shall occur in a manner that minimizes the creation of impervious surface to the extent reasonably practicable. In residential zones, the planting strip may not be converted to impervious surface except as provided in Section 12.04.180; however, existing surfaces need not have impervious surface removed until such time as other development occurs on the site (such as the construction of a garage or other significant change). (Ord. 2017-45 § 32, 2017: Ord. 99-32 § 1(part), 1999).

13.06.070 Service charge rates.

There is hereby levied upon all developed real property within the boundaries of the utility the following service charges which shall be collected from the owners of such properties:

A. For all parcels developed as single-family residences (one equivalent residential unit), the monthly service charge shall be as set forth in the city’s rate ordinance(s); provided, however, that low income citizens may qualify for discounted charges as provided in Chapter 2.102.

B. For all duplexes, triplexes and quadriplexes, the monthly service charge per unit shall be as set forth in the city’s rate ordinance(s).

C. For all other developed property within the boundaries of the utility including public buildings and properties, except as set forth in Section 13.06.080, the monthly service charge shall be the product of the number of equivalent residential units determined by the utility to be contained in such parcel pursuant to Section 13.06.040 multiplied by the rate set forth in the city’s rate ordinance(s).

D. The stormwater rates charged under subsections A through C of this section and the city’s rate ordinance(s) shall be reduced by ten percent for any new or remodeled commercial building that utilizes a qualifying permissive rainwater harvesting system. The city shall consider additional rate reductions in individual cases depending upon the amount of rainwater harvested.

E. Additional stormwater connection charges for storm sewers, pumping stations, disposal plants, or other appurtenances constructed by developers or property owners to serve their own property, but that make stormwater service available to intervening property owned by others, shall be established by “latecomer” or “reimbursement” agreements, that reflect the cost of constructing said facilities. These agreements may be effective for twenty years, after which the connection charges shall revert to the normal connection fees in effect at that time; provided, however, that the term of such agreements may be extended as provided by law. (Ord. 2019-21 § 4, 2019: Ord. 2016-30 § 22, 2016: Ord. 2015-30 § 19, 2015: Ord. 2007-31 § 3, 2007: Ord. 2006-05 § 40, 2006: Ord. 2005-29 § 1, 2005: Ord. 2004-38 § 1, 2004: Ord. 2003-36 § 1, 2003: Ord. 2002-36, § 1, 2002; Ord. 2001-32 § 1, 2001: Ord. 2000-28 § 1, 2000: Ord. 99-32 § 1(part), 1999).

13.06.080 Property exempt from service charges.

The following special categories of property are exempt from service charges.

A. City street, roadway and alleyway rights-of-way;

B. State of Washington highway rights-of-way, so long as the state of Washington shall agree to maintain, construct and improve all drainage facilities contained within such rights-of-way as required by the utility in conformance with all utility standards for maintenance, construction and improvement hereafter established by the utility and so far as such maintenance, construction and improvements shall be achieved at no cost to the utility or to the city;

C. All railroad rights-of way so long as each railroad exempted by this section shall agree to maintain, construct and improve all drainage facilities as required by the utility and in conformance with all utility standards for the maintenance, construction and improvements of such facilities hereafter established by the utility, at no cost to the utility or to the city, and so long as each railroad shall grant to the city, on behalf of the utility, a perpetual easement for the purposes of storm drainage over the entire railroad right-of way within the boundaries of the utility;

D. Property which has been conclusively proven not to contribute in any way whatsoever to surface water runoff or drainage into the storm or surface water system of the city. (Ord. 2007-31 § 4, 2007: Ord. 99-32 § 1(part), 1999).

13.06.090 Collection of charges.

A. All rates, charges, penalties and interest thereon, shall be deemed to be levied upon the respective premises within the boundaries of the utility.

B. The city shall have a lien for all delinquent and unpaid rates, charges, penalties and interest thereon, which lien shall have the superiority established by RCW 35.67.200 and shall be foreclosed in the manner provided in Ch. 35.67 RCW.

C. Delinquent charges shall bear interest at eight percent per annum computed on a monthly basis, and should the city foreclose the lien as authorized by this chapter, the city shall be entitled to its reasonable attorney’s fees.

D. As an additional and concurrent method of enforcing its lien, the utility is authorized, in accordance with law and in the manner provided by Sections 13.04.300 and 13.04.420 and RCW 35.67.290, to shut off water service to such premises for so long as any delinquent fees or charges remain unpaid.

E. The remedies and charges imposed by this section are additional and concurrent to other remedies and charges imposed by this chapter. (Ord. 99-32 § 1(part), 1999).

13.06.110 Authority to promulgate regulations.

The Walla Walla city manager is authorized to promulgate any and all regulations necessary to implement the provisions of this chapter, provided, that such regulations are not inconsistent with either the provisions of this chapter or other applicable law. (Ord. 99-32 § 1(part), 1999).