ARTICLE VIII. WATERCOURSE AMENITIES, SAFETY AND HABITAT

Sec. 29-12. Purpose and intent.

Washes within the urbanized areas of the city in which existing vegetation is maintained are valuable nature resources that contribute to the health and well-being of the residents of the city. Such washes assist in groundwater recharge, support wildlife habitat, and provide natural open space areas. These regulations are specifically intended to accomplish the following:

   (a)   Maximize opportunities for groundwater recharge through the preservation of specific washes with earthen channels and banks.

   (b)   Protect existing vegetation found within and near specific washes.

   (c)   Provide for the restoration of vegetation disturbed as a result of development in and adjacent to specific washes.

   (d)   Assist in the reduction of the urban heat island effect by retaining existing vegetation and minimizing structural improvement of urban washes.

(Ord. No. 7579, § 1, 3-25-91)

Sec. 29-13. Definitions.

   Bank means a mild to steep rise of land which borders and confines the flow of stormwaters or floodwaters and conveys them to some downstream discharge point.

   Basin management plan means a site-specific plan for a watershed or balanced or critical basin which has been approved by the city engineer and which provides a conceptual plan for orderly development of flood control measures within the basin.

   Compound channel means a constructed or modified watercourse which contains and conveys a significant portion of the floodwater within a stabilized lower channel with mild terraces on each side of the low-flow channel, so that the higher watercourse areas can be vegetated to provide for open space and wildlife habitat.

   Development means any human alteration to the natural state of land, including its vegetation, soil, geology, or hydrology for any residential, commercial, industrial, utility, or other uses, including all areas used for vehicular access, circulation, and parking.

   DSD director means the director of the development services department or his designee.

   Gabions means a form of watercourse stabilization wherein the banks and/or bed of the watercourse are protected against erosion and scour from flowing waters. The stabilization consists of rock-filled, rectangular, wire baskets.

   Habitat means the place or type of site where a plant, or animal, or bird naturally or normally grows and lives.

   Native vegetation means vegetation which is indigenous to the specific site or to areas contiguous to the parcel being developed.

   Retention means an engineering/structural method of storing surface runoff water and stopping its downstream progress by employing schemes of containment. No flow is discharged directly into a downstream watercourse from a retention facility. The stored water may infiltrate into the subsurface ground layers.

   Riprap means large, angular rock used to armor or protect the bed and/or banks of a watercourse in a thick layer or blanket of rock material.

   Rock veneer means a blanket of riprap made up of usually small, angular rock used to stabilize the bed and/or banks of a watercourse with a layer of concrete, soil cement, or other similar material to secure the rock in place.

   Site means the land area consisting of a lot or contiguous lots (not including dedicated public property) designed for development as a single entity and exclusive of any abutting public right-of-way.

   Soil cement means an engineering/structural method of stabilizing the bed and banks of a watercourse with a material comprised of a mixture of sands, gravel, and portland cement to produce a natural appearing surface.

(Ord. No. 7579, § 1, 3-25-91; Ord. No. 9967, § 11, 5-17-04)

Sec. 29-14. Applicability.

   (a)   These regulations apply to all lots or parcels of land existing as of April 25, 1991, that are adjacent to the washes listed in table 1.

   (b)   These regulations do not apply to the following:

   (1)   A lot or parcel existing on April 25, 1991, to be developed with one (1) single- family residence or single-family residence accessory structure.

   (2)   A subdivision plat, development plan, or site plan approved prior to April 25, 1991, provided that construction occurs within five (5) years of the effective date of this article [April 24, 1991].

   (c)   The term "city limit line," as used in Table 1, means the city limits as existing on the effective date of an ordinance, adopted subsequent to an annexation, which specifically extends the applicability of these regulations to the newly annexed wash reaches. Notice and hearing for adoption of an ordinance establishing the applicability of these regulations to annexed areas shall be in the same manner as for adoption of an ordinance establishing original zoning boundaries for newly annexed areas.

TABLE 1

   Washes Subject to the Watercourse Amenities, Safety, Habitat Regulations 

      Airport Wash, Santa Cruz River to city limit line

      Alamo Wash, city limit line to Escalante Road

      Arcadia Wash, Glenn Street to 22nd Street

      Arroyo Chico, Park Avenue to Alvernon Way

      Arroyo Chico, 10th Street to First Avenue

      Atterbury Wash, Pantano Wash to Irvington Road

      Atterbury Wash, between Irvington Road and city limit line.

      Cholla Wash, West Branch Santa Cruz River to City limit line

      Christmas Wash, Rillito Creek to Tucson Boulevard

      Citation Wash, Arroyo Chico to Alvernon Way

      Civano Wash, Pantano Wash to city limit line

      Earp Wash, Julian Wash to city limit line

      Este Wash, Tanque Verde Wash to Broadway Boulevard

      Fahringer Wash, between Sabino Creek and Tanque Verde Road

      Globeberry Wash, Silvercroft Wash to Headwaters

      Hidden Hills Wash, Tanque Verde Creek to city limit line

      High School Wash, Tucson Arroyo to Plumer Avenue

      Julian Wash, Tucson Diversion Channel to city limit line

      Kinnison Wash, Atterbury Wash to Irvington Road

      Maxwell Wash, Silvercroft Wash to Anklam Road

      Naylor Wash, Arroyo Chico to Columbus Boulevard

      Nebraska Wash (East), Airport Wash to 12th Avenue

      Pima Wash, Rillito Creek to Oracle Road

      Powderhorn Wash, Anklam Road to Tumamoc Hill

      Racetrack Wash, Rillito Creek to River Road

      Railroad Wash, Arroyo Chico to Country Club Road

      Robb Wash, Tanque Verde to about one thousand (1,000) feet east to Bonanza Avenue

      Rodeo Wash, Santa Cruz River to Alvernon Way

      Rolling Hills Wash, Pantano Wash to Harrison Road

      Rose Hill Wash, Pantano Wash to 22nd Street

      Sabino Creek, Tanque Verde Creek to city limit line

      Sentinel Wash, Cedar Street to Sentinel Peak

      Spanish Trail Wash, Pantano Wash to Houghton Road

      Tucson Park Wash, Silvercroft Wash to Greasewood Road

      Valencia Wash (East), Santa Cruz River to I-19

      West Branch of Santa Cruz River, Santa Cruz River to Valencia Road

      Wyoming Wash, Santa Cruz River to 17th Avenue

(Ord. No. 7579, § 1, 3-25-91; Ord. No. 7944, § 1, 3-15-93; Ord. No. 8310, § 1, 6-20-94; Ord. No. 8779, § 1, 12-2-96; Ord. No. 9427, § 1, 7-10-00; Ord. No. 9489, § 1, 11-20-00; Ord. No. 9501, § 1, 1-22-01)

Sec. 29-15. Development in the study area.

   (a)   Study area established. A study area consisting of the channel, the banks, and the land area extending fifty (50) feet from the banks of the washes listed in table 1, is hereby established.

   (b)   Required study area information. If alterations to the study area are proposed, the following information shall be submitted to the city engineer prior to the issuance of a permit for development in the study area:

   (1)   Hydrology/hydraulic study. A study of the wash and its hydrology and hydraulics is required. In addition to the information required by Chapter 26, Floodplain and Erosion Hazard Area Regulations, the hydrology/hydraulics study shall contain the following elements:

   a.   The location of the 100-year floodplain on, adjacent to, and a minimum of two hundred (200) feet upstream and downstream of the proposed development.

   b.   Soil conditions in and adjacent to the watercourse, and the erosion potential.

   c.   Existing rights-of-way or easement dedication along the wash for a distance of five hundred (500) feet upstream and downstream of the proposed development.

   d.   The existing and proposed ownership of any drainageway facilities on or adjacent to the site and identification of the persons responsible for the maintenance of such facilities.

   e.   Previous hydraulic/hydrology studies or maps prepared for the watershed.

   f.   Groundwater recharge potential at this location.

   g.   Sediment transport characteristics along the watercourse centered on this location.

   h.   Existing and proposed utilities to and across the site.

   i.   Any other elements that may be characteristic of the watercourses on or adjacent to the site.

   (2)   Plant/habitat inventory. All development proposals shall be accompanied by an inventory of the existing vegetation and wildlife habitats within the study area.

   (3)   A copy of the plant/habitat inventory shall be submitted to the development services department for review.

   (c)   Basin management plan. Development on a lot or parcel which is located within the boundaries of an approved basin management plan shall be in conformance with the plan.

(Ord. No. 7579, § 1, 3-25-91; Ord. No. 9967, § 11, 5-17-04)