(A) General.
(1) Except as provided otherwise with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G), water quality controls and the drainage systems to the controls shall be designed, constructed and maintained at a minimum in accordance with the specifications established by the City of Austin Environmental Criteria Manual. Construction of water quality control facilities must begin not later than 18 months after approval of a final site plan providing for such facilities, except as otherwise required in the terms of a variance, administrative approval or modified administrative approval. The applicable watershed development permit shall expire if construction is not commenced before such deadline to commence construction.
(2) Water quality controls shall be required according to the criteria established by this section, except as provided otherwise with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G), as evaluated for each development application. When water quality controls are required, they shall be shown on the slope map, preliminary plats, preliminary site plan, land use site plan, construction site plan and/or the subdivision construction plans.
(a) For water quality controls located in series, the second or later control following sedimentation, extended detention, sedimentation/filtration or similar structure shall not require an impervious liner.
(b) Water quality controls shall be required for golf courses, playfields and similar improved recreational uses where fertilizers, herbicides, or pesticides are applied.
(c) Water quality controls are required for all development regardless of the level of impervious cover. Except as provided otherwise with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G), such controls will be designed to meet the standards of the City of Austin Environmental Manual, as amended, provided that the design therein achieves the greatest pollutant removal efficiency for the particular site conditions.
(d) Vegetative buffers may be used to treat runoff from private driveways and parking areas for single family residential use, or for sidewalks, roof tops, golf courses, playfields, or landscaped areas receiving applications of chemical pesticides or fertilizers. Vegetative buffers shall not be used to treat public, commercial, or multi-family roadways, driveways, or parking areas unless water quality pretreatment is provided. Vegetative buffers shall be designed to meet the applicable standards of the City of Sunset Valley, as well as applicable requirements of the Lower Colorado River Authority (LCRA), City of Austin, and Texas Commission on Environmental Quality, except as provided otherwise with regard to a particular application of a vegetative buffer pursuant to § 150.323(F) and § 150.323(G) vegetative buffers must meet or exceed the standards set forth in § 150.340
(B) Design criteria. The interpretation of the requirements set forth in this chapter shall be made by the City's Engineer or designate, unless specified otherwise by the Council. Water quality controls shall be designed and constructed in conformance with the City of Austin Environmental Criteria Manual, as amended, except as provided otherwise with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G), and be approved by the City's Engineer or other designate of the Council.
(1) Water quality control facilities designed in the Water Quality Transition Zone must be placed as close to the Upland Zone line as technically practical.
(2) Plans are to be submitted to the Texas Commission on Environmental Quality for approval, where required pursuant to state statutes and regulations.
(3) All commercial/office/multi-family construction and all single-family and two-family developments with four lots or more consisting of less than five acres per lot shall provide water quality controls that shall comply with the City of Austin's Environmental Manual, as amended.
(4) (a) Water quality control facilities required pursuant to § 150.336(B)(3) shall be situated and constructed to capture runoff from residential, commercial and multi-family developments and associated streets (including boundary streets).
(b) The water quality controls and drainage into the water quality control basins shall be designed to capture and isolate the first flush of runoff as required in § 150.336(A)(3). All subsequent runoff in excess of the design capacity of the water quality basins shall bypass the water quality facilities and remain segregated in a detention basin up to the designed capacity specified in the City of Austin Drainage Criteria Manual, as amended.
(5) The design of all permanent water quality control sedimentation basins shall allow an average residence time of 24 hours for the water quality volume determined in section § 150.336(A)(3).
(7) Input to and release from detention basins shall utilize grass-lined swales and/or overland flow dispersion measures in conformance with § 150.344.
(C) Maintenance and compliance.
(1) (a) All water quality control facilities and their appurtenances required for development of a commercial lot shall be maintained either by the property owner, or by the city in accordance with a contractual agreement between the city and the property owner. If the property owner will perform the maintenance, a plan for operation and maintenance shall be submitted to the city along with construction plans and must be approved by the City's Engineer or designate.
(b) Water quality control facilities for a commercial lot development shall also require an annual renewal permit in accordance with § 150.336(D)(2).
(2) (a) All water quality control facilities and their appurtenances required for single family and two family residential development shall be maintained by the city after final acceptance, except where otherwise provided in the terms of any variance given in connection with an approval, and except as otherwise provided in divisions (F)(1) [development up to 14% impervious cover in the WQTZ of single family residential property], (F)(5) [development up to 14% impervious cover in the WQTZ of single family residential property using other mitigation] and (G) [single family mitigation measures in the WQTZ] of § 150.323. The city shall not be required to accept for maintenance any water quality control facility which does not meet the criteria established in the City of Austin Environmental Criteria Manual as amended.
(b) Water quality control facilities and their appurtenances to be maintained by the city shall be dedicated to the city by easement or fee simple as the city may require.
(3) All water quality controls and their appurtenances shall be appropriately maintained in accordance with the maintenance standards established by the City of Austin Environmental Criteria Manual, as amended, except as provided otherwise with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G).
(4) Duly authorized inspectors of the city shall have the right of entry on the land or premises where property owners are required to maintain drainage or water quality control facilities, at reasonable times, for the purpose of inspection of the maintenance required. Where facilities are found not to be in good condition, the city shall request in writing that the property owner comply and shall specify the measures required to be taken. If, within 30 days of the notice the maintenance required is not accomplished, the city shall either:
(a) Cause the necessary maintenance to be accomplished and assess the property owner for the city's actual cost; or
(b) Bring an action for mandatory injunction to require the property owner to accomplish the necessary maintenance.
(5) All drainage easements across private property shall contain the necessary language to permit the required water flow, allow and require the maintenance set out herein, and permit the necessary access by the city for inspection and maintenance. All these shall be properly noted on the site plan and/or subdivision plat.
(6) (a) The required maintenance on a commercial lot by a property owner and the power of the city shall be noted in a restrictive covenant agreement to be filed with the Travis County Deed Records.
(b) The applicant shall designate one person or legal entity, with a current address, to which notice shall be given pursuant to this division.
(7) An inspection and renewal permit fee for water quality basins, as specified in the fee schedules adopted by ordinance or resolution, shall be paid at the time of development approval.
(8) A water quality facility located wholly on city property and serving nothing but city property or a public works project shall be maintained by the city.
(9) A water quality facility serving both city property and private property zoned nonresidential or devoted to nonresidential use shall be maintained by the owner of the private property served by the facility, unless the city has otherwise entered into an agreement providing for maintenance of the facility by the city.
(D) Inspection and renewal permit.
(1) At least once each year the city shall inspect the premises of each water quality control required to be maintained by the owner, except that in connection with a water quality control provided pursuant to § 150.323(F) and § 150.323(G), the city may, but shall not be required to perform such inspection.
(2) Any person or entity owning or operating commercial development in the city or ETJ shall obtain and maintain in force an annual renewal permit for the required water quality controls, unless the owner and the city have entered into a contractual agreement whereby the controls will be maintained by the city. A water quality control renewal permit shall be granted or renewed after:
(a) The applicant has filed with the city a maintenance plan in accordance with the City of Austin Environmental Criteria Manual, as amended.
(b) The applicant has illustrated compliance with § 150.336(D)(2)(a) above.
(c) The applicant has paid the permit fee as established by city ordinance and supplied the necessary information to verify that the controls are in proper operating condition.
(3) Upon transfer of ownership of a commercial or multi-family development, the new owners/operators shall obtain a new permit, accept responsibility for the water quality controls at the time of transfer of the development, and document the transfer of the permit on a form provided by the city on or before the date of transfer of the development.
(4) No permit shall be granted or renewed until or unless the permit fee has been paid and the facility is in operating condition as designed. The city shall inspect and accept a report from a registered engineer verifying that the water quality control is in operating condition as designed. The fee shall be paid simultaneously with the filing of the application. No refund or rebate of a permit fee shall be allowed based on denial of the permit, suspension or revocation of the permit, or discontinuance of use of a water quality control. The permit fee shall be sufficient to cover the cost of inspection and review of the report from owner.
(5) Quarterly, beginning with the three-month anniversary of the issuance of the water quality control facility operating permit, permittee must submit documentation that the facility is in proper operating condition, including photographs of the facility. The photos should be dated, and should show, at a minimum, the inlet structure, outlet structures and the condition of any vegetation. The fourth quarter documentation should be submitted together with the annual report required for permit renewal.
(6) Notwithstanding any other provision of this division (D) regarding permit renewals, the provisions of this division (D)(6) shall apply to renewals of permits for water quality controls permitted pursuant to § 150.323(F) and § 150.323(G). A renewal permit shall be obtained on or before each anniversary date of the initial permit on a form provided by the city for such purpose. At the time of sale of the property on which such water quality control is located, a new permit must be obtained, and in connection therewith, the city shall perform an inspection for compliance with applicable design and performance standards. It shall be the responsibility of both the selling and purchasing owner to obtain such renewal permit and to accommodate such inspection by the city.
(E) Fiscal security.
(1) Except with regard to water quality controls permitted pursuant to § 150.323(F) and § 150.323(G), fiscal security shall be required for development in the city and the ETJ to ensure that the water quality controls required are functioning properly. Fiscal security shall be based on an estimate prepared by the developers engineer and reviewed and approved by the city. The estimate shall include, but is not limited to, the cost to construct the temporary and permanent water quality control facilities for the particular site development.
(2) The fiscal security shall be returned to the applicant no earlier than one year after completion of the development, and only upon the receipt of a certified engineering concurrence letter verifying that the controls are constructed in conformance with the approved design as verified after inspection by the city.
(3) In the event the annual inspection required under this chapter reveals that the water quality controls are not being properly maintained or repaired, fiscal security shall be required in connection with the issuance of the next annual inspection and renewal permit. The amount of the fiscal security shall be 10% of the amount which had been required for the initial construction of the water quality control facilities. This fiscal security shall be retained by the city for a minimum of two years to a maximum of five years; however, the city retains the right to extend or reimpose the requirement for fiscal security at any time inspections reveal that the water quality controls are not being maintained or repaired.