Attachment_4_Revised_Statement_of_Work_0001.pdf

Statement of Work (SOW) Project Title: Central Arizona Project – O’Donnell Dam Stabilization and Erosion Control

Agency: Bureau of Land Management (BLM)

Location of Work:

O’Donnell Creek, Las Cienegas National Conservation Area (LCNCA), Arizona T21S R18E Sec. 28 SE NW SE

(31.574829, -110.518019)

Period of Performance: October 2026 – May 2028

Project Objective: This work will use proven, low‑impact watershed restoration techniques to stabilize O’Donnell Creek, protect the integrity of the existing fish barrier, reduce erosion, and support long‑term non-native fish management.

1.0 Introduction

The Bureau of Land Management (BLM) requires contractor support to implement erosion control measures on O’Donnell Creek to stabilize an active headcut, protect an existing fish barrier, and support long‑term watershed and habitat restoration. Work will be conducted using hand tools only and must follow the specifications outlined in the LCNCA Restoration Environmental Assessment Appendix C. Erosion Control Treatment Techniques And Designs (LCNCA EA). (NEPA Number: DOI-BLM-AZ-G020-2019-0031-EA; Project Name: Las Cienegas Landscape Restoration Environmental Assessment)

2.0 Background

Through a series of biological opinions issued in 1994, 2001, and 2008, the U.S. Fish and Wildlife Service (USFWS) determined that the Central Arizona Project (CAP)—a 336‑mile water delivery system supplying Colorado River water to most of Arizona—has the potential to introduce nonnative aquatic species into habitats of federally protected native fishes. In response, USFWS established a Reasonable and Prudent Alternative (RPA) requiring extensive conservation actions, including construction and maintenance of fish barriers, monitoring, nonnative species control, public education, and funding for native fish conservation.

To implement these measures, the Bureau of Reclamation (BOR) and USFWS jointly created the Gila River Basin Native Fishes Conservation Program (GRBNFCP), which operates in partnership with the Arizona and New Mexico Game and Fish Departments, the Bureau of Land Management (BLM), and the U.S. Forest Service. The program focuses on recovery of species such as the Gila topminnow, spikedace, loach minnow, razorback sucker, and Gila chub.

Through a structured process, GRBNFCP evaluates, recommends, and funds conservation

Central Arizona Project – O’Donnell Dam Stabilization and Erosion Control BLM 2026 actions under the CAP biological opinions.

Within the Las Cienegas National Conservation Area (LCNCA), O’Donnell Creek, an intermittent tributary of the Gila River, has long been recognized as a critical habitat area supporting Gila chub, Gila topminnow, and the Northern Mexican gartersnake. GRBNFCP identified two low‑head dams on O’Donnell Creek, an intermittent tributary of the Gila River in LCNCA, as a priority project. These low‑head dams, built in 1959, serve as functional fish barriers that prevent upstream invasion by nonnative species such as green sunfish. Multiple assessments since 2006 have documented structural degradation of the lower dam and headcut advancement near the upper dam, threatening the integrity of the barrier system and increasing the risk of nonnative fish movement into restored habitat upstream.

Over more than a decade, BLM, BOR, and other partners explored several alternatives for fully reconstructing the barriers. However, lack of public consensus and concerns over ecological impact prevented advancement of those proposals. In 2024, a new approach of low‑impact erosion‑control restoration was determined the most feasible and broadly supported option. The GRBNFCP Technical and Policy Committees identified this approach as a priority. Under this direction, BOR provided funding for BLM to implement erosion‑control treatments designed to stabilize the site while maintaining ecological integrity.

A detailed assessment in 2024 confirmed the immediate need for intervention. The downstream dam is no longer effective as a barrier and needs extensive repair that cannot be accomplished with low-impact erosion-control. The advancing headcut around the upper dam threatens the entire tributary to invasive sunfish. In response, BLM and partners propose installing hand‑built erosion control features—such as a Zuni bowl, one‑rock dams, and media lunas—constructed from locally sourced materials. These treatments will slow water flow, stabilize eroding channels, improve hydrologic function, and support vegetative recovery, thereby maintaining the effectiveness of the existing fish barrier system.

The project directly contributes to the recovery and protection of native fish species in the Gila River Basin by preventing nonnative fish invasion, safeguarding restored habitat, and supporting long‑term conservation goals outlined in ESA biological opinions and GRBNFCP strategies.

3.0 Scope of Work

The Contractor shall furnish all labor, equipment, materials, transportation, supervision, and technical expertise necessary to implement erosion control treatments, conduct Year‑2 seeding, and coordinate site access. All structures must conform to the LCNCA EA.

4.0 Applicable Documents

The following documents are incorporated by reference and shall guide all project work:

• Las Cienegas Landscape Restoration Environmental Assessment: NEPA Number:

DOI-BLM-AZ-G020-2019-0031-EA (https://eplanning.blm.gov/)

• O'Donnell Creek Dam Stabilization and Erosion Control Project DOI-BLM-AZ-G020-

2025-0017-DNA (https://eplanning.blm.gov/)

• Project maps and structure layout provided by BLM

• Local Native Seed list (list to be issued and seed source approved by BLM)

• Access and logistics guidance from Appleton-Whittell Research Ranch (AWRR)

5.0 Requirements and Constraints

• Access to staging site and work site must be coordinated with BLM.

• All work must be completed between October 15 and April 1 to avoid migrating bird breeding season and ensure dry-channel working conditions.

• All rock must be sourced from The Nature Conservancy’s Canelo Hills Preserve (approximately 0.5 miles from the site). No rock may be collected from LCNCA.

• Only hand tools may be used for construction. No power tools or heavy equipment are permitted.

• Rock must be sourced locally from the Sonoita, Arizona area to reduce the risk of introducing invasive plant or animal species.

• The staging area for the rock will be located near ranch headquarters (31.590492, - 110.506635); the exact location will be coordinated with BLM. The rock may be delivered to the staging area by a large dump truck if needed. From there, it will need to be transported to a parking area near the work site using pickup trucks.

• The project site is located within a riparian channel. All materials and hand tools will need to be transported from the parking area to the project site without the use of mechanized equipment, using wheelbarrows, buckets, or by hand.

• Rock must be transported from Canelo Hills Preserve to O’Donnell Creek by hand or wheelbarrow; no mechanized collection or transport is allowed.

• All seeds must be locally collected native species. The list and seed source must be approved by BLM prior to use.

• The Contractor shall follow all site access instructions from and coordinate regularly with

BLM.

6.0 Tasks

Task 1: Project Mobilization and Coordination

The Contractor shall:

• Attend a kickoff meeting with BLM representatives.

• Review worksite maps, access routes, and designated structure locations.

• Submit a Work Plan describing sequencing, labor needs, safety procedures, and materials transport.

• Coordinate site access with BLM and AWRR.

Task 5 Task 2: Material Acquisition and Transport The Contractor shall:

• Collect all rock materials from the approved Canelo Hills Preserve collection area (approximately 0.5 miles)

• Transport materials from Canelo Hills Preserve by hand or wheelbarrow only

• Ensure responsible environmental stewardship during collection. Materials

• Obtain rock for the project from a locally approved source

• Follow the above procedures for rock transportation

• Not collect rocks within the boundaries of LCNCA.

• Source locally collected, native seed that has been preapproved by BLM

Task 3: Construct One Zuni Bowl Headcut Stabilization Structure (Figure 1)

• Build a Zuni bowl at the upstream fish barrier following guidance in the LCNCA EA.

Size of the headcut is approximately 35.5 feet long, 16 feet wide and 4.5 feet at its deepest depth (approximately 55 cubic yards).

• Install rock-lined step falls and plunge pools designed to dissipate water energy and halt headcut migration.

• Ensure minimal disturbance to existing vegetation and natural channel morphology.

Figure 1: Zuni Bowl Construction

Task 4: Install a Series (3 to 4) of One‑Rock Dams (Figure 2)

• Build a series (between 3 and 4 total) one‑rock‑high grade control structures across the channel.

• Use larger footer rocks placed in the channel’s lowest points, followed by smaller stones outward.

• Ensure structures are level bank‑to‑bank and meet LCNCA EA specifications.

Figure 2: One Rock Dam

Task 5: Install One Media Luna (Figure 3) The Contractor shall:

• Construct one media luna sheet‑flow spreader to disperse concentrated runoff.

• Install tucked footer rows, offset stones, and curved shape as specified.

• Place structures to restore sheet flow and reduce erosion.

Figure 3: Media Luna

Task 5: Material Acquisition and Transport

• Collect all rock materials from the approved Canelo Hills Preserve collection area (approximately 0.5 miles)

• Transport materials from Canelo Hills Preserve by hand or wheelbarrow only

• Ensure responsible environmental stewardship during collection. Materials

• Rocks may not be collected on LCNCA.

• Source locally collected, native seed that has been preapproved by BLM

Task 6: Year‑2 Seeding and Structure Maintenance The Contractor shall:

• Apply BLM‑approved locally sourced native seed one year after initial construction.

• Conduct structural maintenance, reinforcement, or adjustments as needed or directed by BLM during the seeding site visit

7.0 Deliverables (Reports)

Deliverable 1: Work Plan (Due within 15 days of award) Includes schedule, access plan, materials collection strategy, safety approach, and coordination plan.

Deliverable 2: Completed Zuni Bowl Structure Documented with photos and verified by BLM in the field.

Deliverable 3: Completed One‑Rock Dams and Media Lunas As‑built documentation including photos and maps.

Deliverable 4: Year‑2 Seeding and Structure Maintenance Report Includes seed sources, application methods, structure adjustments, and photo documentation.

Deliverable 5: Final Project Summary Report Submitted within 30 days of project completion and includes:

• Description of all work completed

• Before/after photos

• Structure locations (maps or sketches)

• Recommendations for future monitoring or maintenance

8.0 Schedule

Milestone Timeline Project Kickoff Meeting Within 7 days of award

Deliverable 1: Work Plan Within 15 days of award

Milestone Timeline Construction Window October 15 – April 1 (Year 1)

Construction Completion No later than April 1, 2027

Year-2 Seeding & Maintenance October 15 – April 1 (Year 2)

Final Report Due Within 30 days of Year-2 visit

9.0 Government Furnished Information & Support

BLM will provide:

• Approved structure locations for one rock dams and media lunas prior to construction

• Approved seed sources and approved seed list

• Project maps and environmental documentation

• On‑site inspection and approval of completed structures

• Guidance on site access

The BLM will not furnish tools, materials, or labor.

10.0 Performance Standards

• Meet or exceed all technical specifications in the LCNCA EA

• Ensure structural stability and proper installation

• Maintain compliance with environmental and seasonal restrictions

• Follow all site access logistical requirements

• Provide complete and timely deliverables