Chapter 18.65


18.65.010    Purpose.

18.65.020    Definitions.

18.65.030    Applicability.

18.65.040    Exceptions.

18.65.050    Description of regulated riparian habitat.

18.65.060    Habitat disturbance.

18.65.070    Mitigation.

18.65.080    In-lieu fee option.

18.65.090    Review process, criteria and approval.

18.65.100    Modification of development standards in riparian areas.

18.65.110    Appeals and variances.

18.65.120    Riparian habitat maps.

18.65.010 Purpose.

The purpose of this chapter is to preserve and/or enhance riparian vegetation and habitat along watercourses and floodplains, and to:

A. Promote benefits provided by riparian habitat resources, including but not limited to groundwater recharge, natural erosion control and protection of surface-water quality.

B. Assist the long-term stability of natural floodplains and survival of the full spectrum of plants and animals that are native to the Sahuarita region and Santa Cruz valley by:

1. Encouraging preservation and future survival of riparian habitat by promoting minimum disturbance of habitat during development;

2. Supporting the continuity of riparian habitat along watercourses;

3. Providing land-use guidance for avoiding, minimizing and mitigating damage to important riparian areas; and

4. Providing ecological sound transition between riparian habitat and developed areas.

C. Provide an economic benefit to the region by providing aesthetic value, recreational opportunities and promoting wildlife values by preserving riparian habitat for the enjoyment of residents and visitors. [Ord. 2013-077 § 3.]

18.65.020 Definitions.

A. For the purposes of this chapter, certain words and phrases shall have special meaning as defined herein, unless the context otherwise requires:

1. “Ephemeral” means streams that flow only during and immediately after rain.

2. “Erosion” means the wearing away of the ground surface because of the movement of wind, water or ice.

3. “In-lieu fee” means fees collected by the town and is required of an owner or developer when disturbance to regulated riparian habitat occurs under the in-lieu fee option.

4. “Mitigation” means providing a new riparian habitat of similar quality to an area that had plant life removed because of physical improvements or development. The property is typically located within the floodplain, erosion hazard area, or riparian habitat.

5. “Mitigation plan” means a document submitted by the applicant to the town that clearly delineates regulated riparian habitat and the limits of development on a site. The mitigation plan indicates mitigation area(s) and includes a plant list (species/quantities), and irrigation methods.

6. “On-site riparian habitat exchange” means the process involving the exchange of unmapped riparian habitat with designated and mapped riparian habitat.

7. “Regulated riparian habitat” means riparian habitat areas within the town of Sahuarita identified on the riparian classification maps as established by this chapter and adopted by town council.

8. “Restoration” means the process of repairing a previously disturbed, damaged, or degraded site area or site feature and replicating its previously undisturbed, undamaged, or ungraded condition of vegetation, plant communities, geologic structures, grade, drainages, and riparian habitat that historically existed on site or in the neighborhood.

9. “Riparian habitat” means plant communities that occur in association with any spring, cienega, lake, watercourse, river, stream, creek, wash, arroyo, or other body of water, either surface or subsurface, or channel having banks and bed through which waters flow at least periodically.

10. “Understory” means the shrubs and plants growing beneath the main canopy of a forest.

11. “Watercourse” means any lake, river, stream, creek, wash, arroyo or other body of water or channel having banks and bed through which waters flow at least periodically.

12. “Xeroriparian A” means riparian habitat generally associated with well-developed riparian areas and is the densest xeroriparian subcategory. The vegetative volume is greater than 0.856 cubic meters per square meter (M3/M2).

13. “Xeroriparian B” means riparian habitat typically occurring along well-developed riparian areas and is a moderately dense xeroriparian subcategory. The vegetative volume is less than or equal to 0.856 cubic meters per square meter (M3/M2) and greater than 0.675 cubic meters per square meter (M3/M2).

14. “Xeroriparian C” means riparian habitat that typically occurs along minor riparian areas and along the peripheral edges of major riparian areas and is less dense than xeroriparian A and B. The vegetative volume is less than or equal to 0.675 cubic meters per square meter (M3/M2) and greater than 0.500 cubic meters per square meter (M3/M2). [Ord. 2013-077 § 3.]

18.65.030 Applicability.

A. This chapter shall apply to all properties within the town that contain riparian habitat, as delineated on riparian habitat maps adopted by the town council.

B. All requirements of this chapter shall apply to regulated hydroriparian, mesoriparian and xeroriparian classes A, B, and C habitat disturbed during any of these actions:

1. New development;

2. Expansion of structures that require a town building permit, zoning clearance or floodplain permit;

3. Type 1 and Type 2 grading permits issued by the town per STC Title 16;

4. Land development permits associated with subdivisions (Chapter 18.69 STC); and

5. Land development permits associated with commercial development plans (Chapter 18.71 STC). [Ord. 2013-077 § 3.]

18.65.040 Exceptions.

A. Exceptions to the chapter include:

1. Existing buildings constructed before April 24, 2006;

2. Final plats, development plans, and rezoning approved prior to April 24, 2006;

3. Single-family residential lots with dwellings constructed prior to April 24, 2006. [Ord. 2013-077 § 3.]

18.65.050 Description of regulated riparian habitat.

A. For purposes of this chapter, “a regulated riparian habitat” is defined by the riparian classification maps adopted by the town council. These habitats are generally characterized by vegetation that is different in plant species composition or an increase in the size and/or density of vegetation as compared to upland areas. They occur in association with regulatory floodplains through which waters flow at least periodically, as well as any spring, cienega, lake, watercourse, river, stream, creek, wash, arroyo, or other body of water. These communities represent a continuum of plant species’ response to available moisture.

B. Regulated riparian habitats are divided into three classifications and provide ecological connectivity and biological corridors.

1. Hydroriparian. Riparian habitats generally associated with perennial watercourses and/or springs. Plant communities are dominated by obligate or preferential wetland plant species such as willow and cottonwood.

2. Mesoriparian. Riparian habitats generally associated with perennial or intermittent watercourses or shallow groundwater. Plant communities may be dominated by species that are also found in drier habitats (e.g., mesquite), but contain some preferential riparian plant species such as ash or netleaf hackberry.

3. Xeroriparian. Riparian habitats generally associated with an ephemeral water supply. These communities typically contain plant species also found in upland habitats; however, these plants are typically larger and/or occur at higher densities than adjacent uplands. Xeroriparian habitat is typically divided into four subclasses, three are recognized by the town: class A, B, and C habitat. Mitigation in xeroriparian habitat is to be determined based at least on total vegetative volume (TVV) as provided within the mitigation standards as well as replacement of other lost riparian habitat functions necessary to sustain riparian habitat. [Ord. 2013-077 § 3.]

18.65.060 Habitat disturbance.

A. Riparian habitat disturbance that requires submittal of a mitigation plan:

1. Any disturbance of hydroriparian or mesoriparian habitat.

2. Disturbances to xeroriparian class A, B, and C riparian habitat are measured according to the following chart:

Habitat Area

Disturbance Trigger for Mitigation

Up to 10 acres

1/3 of an acre disturbance or greater

10.01 – 50 acres

1 acre of disturbance or greater

50.01 – 100 acres

1.5 acres of disturbance or greater

Greater than 100 acres

2 acres of disturbance or greater

B. Riparian habitat disturbance that requires submittal of a site plan includes disturbances less than one-third of an acre of xeroriparian A, B and C habitat.

C. Review and approval of a mitigation plan by the planning and building director are required for disturbances listed in subsection A of this section.

D. Review and approval of a site plan by the planning and building director are required prior to habitat disturbance.

1. Submittal of a site plan is required when less than one-third of an acre of xeroriparian A, B or C habitat is disturbed.

2. The site plan must be prepared according to STC 18.65.080(C)(2). [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.070 Mitigation.

A. Prior to submittal of a mitigation plan, the applicant shall schedule a development review committee (DRC) meeting with the planning department.

B. After the applicant has had a DRC meeting, the applicant may move forward and revise the location of riparian habitat location on the project site and file a map correction.

C. The riparian habitat maps indicate the general location of riparian habitat. When applied to a smaller scale or specific parcel, corrections of riparian habitat boundaries may be needed. The property owner may request a revision to the riparian habitat boundary. The property owner must conduct a field study according to Appendix F (Field Mapping and Onsite Vegetation Survey) in the Riparian Habitat Mitigation Standards and Implementation Guidelines manual and submit an exhibit that demonstrates that the existing habitat boundaries are not accurate. The study must be sealed by a licensed landscape architect, qualified biologist, arborist or registered engineer.

D. Classification Riparian Map Review.

1. Review by the planning and building director is required to verify the field study and proposed location of riparian habitat on the project site.

2. The planning and building director will consult with the town engineer to determine if the field study is complete and can be used to modify the location of on-site riparian habitat.

E. The applicant is required to consult with the town engineer/floodplain administrator regarding floodplain permitting prior to submittal of a mitigation plan and prior to any disturbance of the site.

F. All mitigation plans submitted shall be reviewed by planning staff and the DRC. The DRC shall provide a recommendation to the planning and building director.

G. Mitigation plans submitted must be accompanied by exhibits and narratives that demonstrate that disturbance of regulated riparian habitat cannot reasonably be avoided. These exhibits and narratives must show the applicant has attempted some of the following approaches to their project:

1. Avoidance of habitat.

2. Minimizing disturbance.

a. Reducing grading limits;

b. Reducing building footprint;

c. Reorienting the structure; and

d. Reducing the width, length and/or relocating driveways and parking areas.

3. Proof of modification of development standards submittal in accordance with STC 18.65.100.

4. At the request of applicant, additional development standard modifications may be accepted if they promote the purpose of this chapter.

H. The mitigation plan shall delineate all mitigation measures to be taken by the owner and shall include a project timeline estimate. The mitigation plan shall be consistent with the town Riparian Habitat Mitigation Standards and Implementation Guidelines and shall be prepared in accordance with best management practices (BMP). The mitigation plan shall identify the following:

1. Mitigation methods used for the project, especially if a combination of mitigation approaches is proposed (habitat exchange, subsection K of this section, modified development standards, etc.) for the project;

2. Locations of habitat(s) for mitigation depicted as a site plan and mitigation planting plan;

3. Location of mitigation site in relationship to existing untouched regulated riparian habitat;

4. Location(s) of selective clearing, grading, erosion control and other habitat manipulation actions;

5. Construction techniques that identify and protect riparian habitat during construction (e.g., temporary fencing);

6. Method of replacement of affected vegetation with appropriate plant species in ratios that will result in simulation of the pre-alteration vegetation within a minimum of three years with the option of extending to five years;

7. Irrigation in accordance with STC 18.73.030(H) used with passive water harvesting, where possible, or installation and maintenance of irrigation methods until plantings are established;

8. Information on the periodic monitoring of mitigation features, starting with the first year after installation of plants and irrigation, and extending up to five years, with a minimum of three years required. The extension of monitoring past three years will be determined by planning staff based on the condition of the habitat;

9. Maintenance and replacement of damaged plantings.

I. Proposals using the in-lieu fee option are required to include the following information:

1. Submittal of a spreadsheet with information giving the cost to mitigate (per acre/square foot) the site planned for disturbance. The spreadsheet is required to have the following components:

a. Plant material (quantity and size of trees, shrubs and groundcover);

b. Labor for installing plant material;

c. Hydroseed (seed, mulch, water, cost for machinery, and labor to apply seed);

d. Irrigation (materials and labor for installation);

e. Data evidencing up to five years, with a minimum of three years, maintenance and monitoring (removal of noxious/invasive weed species, water, replacement plants, etc.); and

f. Other miscellaneous work, such as grading and/or construction of water harvesting basins.

2. The spreadsheet must be prepared by a licensed landscape architect, qualified biologist, arborist or registered engineer.

J. For larger developments, an alternative to providing a mitigation plan for xeroriparian habitat A, B and C is available in the form of a conservation plan.

1. Applicants may propose a conservation plan as an alternative to a riparian habitat mitigation plan.

2. A conservation plan is designed to support the success of on-site preservation of riparian areas and the mitigation of disturbed habitat, as well as serve the special needs of a given project within the context of its natural resources, both upland and riparian.

3. A conservation plan may be an available option when traditional on-site mitigation does not address unique ecological or project conditions.

4. The proposed conservation plan must preserve, enhance, provide connectivity, overall function, and/or restore an impacted riparian system and/or its surrounding areas. This can be performed by submitting proposals for an on-site riparian habitat exchange, restoration, or preservation of habitat to the planning and building director for approval.

5. Proposal of a conservation plan is subject to the discretion and approval of the planning and building director in consultation with the town engineer, acting as floodplain administrator.

6. A conservation plan is approved by the planning and building director in consultation with the town engineer, acting as floodplain administrator.

K. A site proposed for development may have areas located outside the mapped regulated riparian habitat that have a similar or greater ecological value as the mapped habitat. The property owner has the option to quantify these areas by surveying and delineating the area proposed for protection.

1. In order for a habitat to qualify for an on-site exchange, restoration or preservation, the regulated riparian habitat proposed for disturbance and proposed habitat for exchange must be surveyed to verify the riparian habitats are of equivalent ecological value and part of the same parcel planned for development prior to proposal for an on-site habitat exchange.

L. Acceptable methods used to prepare a mitigation plan are identified in the town document titled Riparian Habitat Mitigation Standards and Implementation Guidelines on file with the planning department. [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.080 In-lieu fee option.

A. At the request of the property owner and with planning and building director approval, the mitigation plan requirement under this chapter may be waived by contributing funds to an account established and administered by the town.

B. The in-lieu fee option may be proposed after the applicant has attempted each of the following and shown that it cannot provide relief from disturbance:

1. Avoidance is not possible and impacts to regulated riparian habitat have been minimized.

2. The ability to mitigate entirely on site has proven not feasible.

3. Use of the modification of development standards in riparian areas does not provide relief from disturbance to riparian habitat.

C. The in-lieu fee option is based on riparian classification, estimated cost of on-site mitigation, including monitoring and long-term maintenance and a consideration of inflation adjustment. The following items are required for submittal with the in-lieu fee proposal:

1. The in-lieu fee spreadsheet, as described in STC 18.65.070(I).

a. A standard value will be assigned for each mitigation component and will be based on average cost estimates obtained from a landscape architect, arborist, or biologist. The applicant is required to provide two cost estimates (within recent 90 days of submittal).

b. The average cost between the two estimates will be used to determine each spreadsheet component in order to calculate the in-lieu fee for the project.

c. The spreadsheet will allow each component of the mitigation plan to be calculated separately so the total mitigation costs can be accurately assessed for each project.

2. A detailed site plan with the following information:

a. Title block with name and address of development (include on all sheets).

b. Graphic scale, north arrow, location map and a brief legal description of site location with township, range and section information.

c. Town case number for the project and any related case numbers (rezoning, conditional use permit, tentative plat, development plan, etc.).

d. Name, address and phone number of developer, owner and architect/engineer professional seal or firm preparing the plans.

e. Date of drawing and/or last revision.

f. All property lines with proposed and existing development and infrastructure.

g. Delineation of all riparian habitat and habitat types must be labeled.

h. Acreage or square footage of regulated riparian habitat prior and after disturbance must be indicated.

i. Total habitat disturbance acreage with habitat disturbance percentages provided.

j. Building footprint with proposed structures including: uses, square footage, height, dimensions, finished floor elevations, and setbacks to property lines.

k. Demonstration that disturbance of regulated riparian habitat cannot be avoided and attempts to minimize disturbance through the modification of development standards outlined in STC 18.65.100 have been attempted.

l. Demonstration that disturbance of regulated riparian habitat does not fracture landscape linkages and biological corridors but maintains the continuity of habitat.

m. All existing and proposed structures and conditions within 100 feet of project.

n. Legend with all symbols described.

o. Scaled vicinity map showing a one-square-mile area with project site at the center of the map.

p. Note all ground planes, i.e., asphalt, concrete, decomposed granite, etc.

q. Property boundary with dimensions, bearings, and distance.

r. Location of all existing and proposed easements, indicate if public or private.

s. Contour lines at two-foot intervals.

t. One-hundred-year floodplain and erosion hazard limits.

u. On-site roadways and adjacent roadways together with sidewalks and trail systems.

v. Location and dimensions of all sidewalks and pedestrian paths.

w. Location of temporary safeguard fence to protect undisturbed area.

x. Significant rock outcroppings or other natural features.

D. In-lieu fees obtained by the town will be used toward the purchase of property with high value riparian habitat and toward town projects that may include restoration, enhancement, and/or preservation of regulated riparian habitat. The overall objective of the in-lieu fee is to restore, enhance and protect riparian habitat in one area to compensate for negative impacts to regulated riparian habitat that occur within the town.

1. In-lieu fees shall be collected by the town prior to disturbance of the project site or issuance of floodplain permit or grading permit in accordance with STC 14.20.030.

2. Establishment of an in-lieu fee accounting system shall be established and monitored by the town finance department and planning and building director. [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.090 Review process, criteria and approval.

A. The applicant is required to schedule a pre-submittal meeting with the development review committee (DRC) prior to submittal of riparian habitat mitigation plan or site plan.

B. Site plans shall be submitted to the planning and building director for review for xeroriparian A, B, and C regulated riparian habitat disturbances less than one-third of an acre.

C. Riparian habitat mitigation plans are submitted to the town planning and building department for review. The submittal shall include the following information:

1. A detailed site plan in accordance with STC 18.65.080(C)(2).

2. Evidence that no reasonably practicable alternative exists and impact to regulated riparian habitat has been minimized to the maximum extent practicable.

3. An exhibit that delineates regulated riparian habitat in accordance with the riparian classification maps, or site-specific delineation of regulated riparian habitat. The regulated riparian habitat delineation shall be prepared at the same scale as the plat or development plan, and shall include:

a. Location of parcel boundaries and regulated riparian habitat delineated on the aerial photograph;

b. Limits of development on the site, including existing and proposed improvements;

c. Grading limits; and

d. Location of all improvements and utility lines.

4. Mitigation planting plan.

5. Development plan (Chapter 18.71 STC) or tentative plat (STC 18.69.050) and landscape plan (STC 18.73.060).

6. Summary of requested development standard modifications, if applicable.

7. Posting a performance bond or financial assurances in accordance with STC 18.69.070(E)(2).

D. The process shall include planning staff and DRC review of all material submitted, including the justification for disturbance of regulated riparian habitat; additional materials may be requested at this time. Recommendations will be given to the planning and building director from the DRC. The planning and building director will approve or deny all proposed mitigation plans.

E. The application and any proposed mitigation plan shall be evaluated for the following criteria:

1. Avoiding the impact;

2. Minimizing the impact;

3. Rectifying the impact;

4. Reducing or eliminating the impact over time; and

5. In-lieu fee proposal for the impact, if applicable. [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.100 Modification of development standards in riparian areas.

A. Whenever a development plan or subdivision plat requires a mitigation plan to promote the protection of riparian habitat as defined by this chapter, development standards may be modified in accordance with this section.

B. Any such modification shall be consistent with the purpose of this chapter, and may only be allowed:

1. When a mitigation plan required by this chapter would be unnecessary if the modification is granted; or

2. When development within the riparian habitat area cannot reasonably be avoided and an application for modification is submitted as part of a mitigation plan submitted pursuant to this chapter.

C. Permit applications shall include:

1. Evidence that no reasonably practicable alternative exists to the proposed impact on mapped habitat and evidence that the impact has been minimized to the maximum extent practicable;

2. A map delineating riparian habitat boundaries and clearly delineating areas of proposed disturbance to mapped riparian habitat prepared by a licensed landscape architect, biologist, arborist or registered engineer;

3. A description of the vegetation that will be disturbed;

4. A habitat mitigation plan for disturbance to mapped riparian habitat areas as provided in the town Riparian Habitat Mitigation Standards and Implementation Guidelines when required by the planning department; and

5. Such additional supporting information as the planning department determines to be necessary to carry out review under this chapter.

D. Conditions may be placed on the permit to the extent reasonably practicable, requiring preservation or mitigation of the riparian habitat. If mitigation is required, compliance with an approved habitat mitigation plan shall be made a condition of the permit.

E. Development standards may be modified consistent with subsection A of this section, including but not limited to the following:

1. The planning and building director may modify any minimum setback or distance between structures. The modification shall be processed pursuant to the procedures and standards of STC 18.85.020, except that no fee shall be charged.

2. The town council, pursuant to the procedures and standards of STC 18.09.040, may approve cluster development for subdivision lots during the platting phase in order to promote the protection of riparian habitat and undisturbed natural areas. Additional undisturbed natural area may be included in the preserved area if at least one acre or 10 percent of the total preserved area is riparian habitat as defined in this chapter. Such lot size modifications are available only where an area of riparian habitat and undisturbed natural areas will be owned by a homeowners’ association and preserved from alteration by recorded covenants running with the land enforceable by the town. The total square feet by which the area of each lot in the subdivision is reduced shall not exceed the square feet of the preserved area. No more lots shall be allowed by the reduction than would be allowed without the reduction.

3. The planning and building director may modify off-street parking requirements, pursuant to Chapter 18.75 STC, when it is demonstrated that such a reduction in parking will not significantly decrease parking in a manner that will result in danger to persons, adjacent properties or increase in traffic.

4. The planning and building director may approve the reduction of the number of trees in bufferyards required pursuant to Chapter 18.73 STC up to 50 percent when riparian habitat in an area regulated by the town pursuant to this chapter is preserved. Measurement of the riparian vegetation shall be done by aerial canopy coverage or an alternative means acceptable to the town. The measurement of the square footage of the riparian vegetation shall be rounded up to a whole number.

5. An owner or a developer may request additional development standard modifications that promote the purposes of this chapter. Any such request shall be reviewed by the planning and building director for statutory or ordinance provisions, including the appeals process or a development agreement approved by the town council. [Ord. 2016-107 § 1; Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.110 Appeals and variances.

A. Appeals.

1. A property owner or applicant may appeal the written decision concerning the interpretation of adopted riparian maps, location of riparian habitat or administration of this chapter. Submittal of the appeal shall be in writing to the planning and building director within 30 days from receipt of the written decision.

2. The appeal submitted shall contain a detailed explanation of all matters in dispute, including any documentation supporting the appeal.

3. Within 10 working days of receipt of the written appeal, the planning and building director and town engineer may meet with the property owner to discuss the appeal and request additional information deemed necessary.

4. Appeals involving hydroriparian or mesoriparian shall be held by the town council as a public hearing.

5. Appeals involving xeroriparian habitat A, B or C shall be held by the town planning and zoning commission as a public hearing.

B. Any property owner requesting a variance from the requirements of this title or from this chapter and/or requesting a waiver to mitigation standards shall request a variance through the planning and building director in accordance to STC 18.93.030. [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]

18.65.120 Riparian habitat maps.

A. Riparian habitat maps shall be adopted by resolution of the town council and shall detail, on a parcel level, the general location of riparian habitat subject to the requirements of this chapter.

B. When a question arises as to the location of any regulated riparian habitat the question shall be decided by the planning and building director in consultation with the town engineer, acting as floodplain administrator.

1. Any person contesting the location of any riparian habitat boundary shall be given a reasonable opportunity to present technical evidence or exhibits that provide assistance in determining the boundary of habitat as described in STC 18.65.070(C).

C. The planning and building director’s decision shall be final, except as provided for in STC 18.65.110.

D. The riparian classification maps shall be kept on file and made available to the public at the planning department. [Ord. 2015-098 § 1; Ord. 2013-077 § 3.]