“Via E-Mail”
[email protected]
June 12, 2026
Ms. Carla Callahan
City of Santa Clarita
23920 Valencia Blvd.
Santa Clarita, CA 91355
Subject: Proposal for Professional Engineering Services Haskell Canyon - Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
Dear Ms. Callahan:
Psomas is submitting the attached proposal for professional services for the subject project. Based on our knowledge of the site and the information provided to us, we have developed the attached Scope of Services and associated fee to meet the project requirements, as we understand them, as described in Exhibit “A” and Schedule “A” respectively (attached).
We look forward to working with you on this important project.
Sincerely,
Jeremy Johnson, PE
Sr. Project Manager
JJ:bh
Enclosures (5)
− Exhibit “A”: Scope of Services
− Schedule “A”: Fee Schedule
− Hourly Rates
− Billing Procedures
− Exhibit “A-1” Work Limit
EXHIBIT “A”
SCOPE OF SERVICES
Proposal for Professional Engineering Services
Haskell Canyon – Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
PROJECT DESCRIPTION
The City of Santa Clarita (city) is proposing the development of two Arizona crossings at Haskell Creek, north of Copper Hill Drive. Crossing 1 is between the main canyon road and the city’s archery facility and will replace an existing temporary culvert crossing. Crossing 2 is south of Crossing 1 and will be between the main canyon road and the city’s proposed mountain bike park. The civil engineering scope is to perform hydrologic and hydraulic analysis of Haskell Creek and design of a paved Arizona crossing with cutoff walls. Surveying scope is also included to support the civil engineering design. Psomas was provided with information via phone conferences with Carla Callahan and an email on April 15th. Please see attached Exhibit “A-1” for the proposed limits of surveying and civil engineering work.
SCOPE OF WORK
Psomas agrees to furnish and perform the various professional services pertinent to the project specifically outlined as follows:
Surveying Services
The Consultant agrees to prepare a Design Survey for the project. Specific items of service are as follows:
• Prepare a survey map situated on NAD83 state plane coordinate system at a scale of 1" = 10’ over the site shown on attached Exhibit “A-1” delivered in both hardcopy (scaled PDF plot) and AutoCAD format.
• Property lines established from field surveyed information, available county record. It is assumed that deed/title review is not required. Plotting of easements is excluded. • Horizontal location, size and description of driveways, roads, fences, signs, poles, site trees over 4" in diameter, and other permanent surface visible features. • Topography situated on presiding municipal datum as established by city benchmarks at a 1-foot contour interval, and spot elevations on a grid pattern in level areas. • Elevations on roads, dirt, and other built improvements as depicted on attached Exhibit “A-1”.
EXHIBIT “A”
SCOPE OF SERVICES
Proposal for Professional Engineering Services
Haskell Canyon – Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
Civil Engineering Services
Hydraulic Analysis
The Haskell Canyon wash is currently mapped by FEMA as a Zone AO with a three foot flood depth for the 100-year storm event, and has also been mapped by LA County for the Capitol Storm event. Both floodplains are wide, extending west, beyond the dirt roadway limits.
An “Arizona Crossing” is a low water crossing typically designed for ephemeral flows that allows vehicles to cross when flows rates and depths are small through construction of a stabilized crossing. The stabilized crossing is typically a widened concrete structure that is superelevated in the direction of flow and has concrete toe downs/ford walls along its upstream and downstream edges that extend below a calculated scour depth. The length of the structure is determined by the floodplain width to which the protection is desired and can range from a 90th percentile storm event to a 100-year or larger storm event. Crossings can also be constructed with small culverts to maintain a dry road during minor storm events and allow overtopping during large storm events.
The County capitol storm design flow is 12,800cfs with a 2-year storm event design flow rate of ~4,900 cfs based on the ratios for different storm events provided in the LA County Hydrology Manual. The FEMA 100- year design storm flow rate for its floodplain mapping purposes is 3,320cfs for a 9.8 sq.mi. drainage area and has a 10-year flow rate of 730 cfs. Psomas recommends designing the low flow crossing for a flow rate no less than the FEMA 10-year storm event value, and will prepare hydraulic analyses and design for a single storm event with flow rates based on the values available in the FEMA FIS or approved capitol storm flow rate with a factor from the LA County Hydrology Manual applied. Alternatively, Psomas can evaluate a single flow of the City’s choosing or establish a flow rate based on any county observations and/or existing crossing and channel topography.
Psomas will prepare a 1D or 2D hydraulic model using HEC-RAS and a steady state flow condition. The model will be prepared using the best available elevation data for the area as obtained online from the USGS or can use an existing model if available from the City. Psomas will initially model LA County 2-year event and the FEMA 10-year event to determine floodplain extents during those two events which will be presented to the City to choose one for design, or decide on an alternative flow rate between the two values. Results from the hydraulic model for the chosen design storm flow rate will be used to evaluate general scour available equations and the flow depths, velocities and other hydraulic parameters. Should an equation rely on sediment size, a typical grain size from available nearby study or based on observed site conditions will be assumed.
The crossing design will be at or below existing grade in order to ensure no impact to the FEMA Floodplain mapped depths, which makes construction of low flow culverts beneath the roadway impossible without development of a CLOMR and LOMR.
Results of the hydraulic analyses and recommendations for design, which include floodplain widths, flow depths and velocities, scour depths, cross slope recommendations, toe down depth recommendations, and concrete width and length recommendations will be summarized in a technical memorandum for review and acceptance by the City of Santa Clarita and included with the construction document submittal.
EXHIBIT “A”
SCOPE OF SERVICES
Proposal for Professional Engineering Services
Haskell Canyon – Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
Arizona Crossing Design
Psomas will prepare civil engineering design and construction documents for the proposed Arizona crossings at Haskell Canyon based on the approved hydraulic design criteria. The design will incorporate a paved low-water crossing constructed at or near existing grade and will include appropriate cutoff (toe-down) walls to address anticipated scour depths and velocities. Design elements will consider floodplain extents, flow depths, cross slopes, and constructability while avoiding impacts to the FEMA-mapped floodplain. Construction documents will include cover and general notes, plan and profile sheets, typical sections, construction details, and design cross sections (for reference only) necessary to support bidding and construction of the improvements in accordance with City standards.
Specifications and Engineer’s Estimate
Psomas will prepare specifications and an engineer’s cost estimate. The specifications will be in a format consistent with the 2018 Standard Specifications for Public Works Construction (SSPWC) and the city’s specification templates. The engineer’s cost estimate shall include a breakdown of costs for each item of work and match the bid schedule, item by item, included in the specifications.
Meetings and Coordination
Psomas will provide project-related meetings and coordination services in support of the design efforts of the Arizona crossings. Services include participation in meetings with the City and project stakeholders to discuss project status, design progress, and technical issues, as well as ongoing coordination with City staff as needed throughout the design phase.
EXHIBIT “A”
SCOPE OF SERVICES
Proposal for Professional Engineering Services
Haskell Canyon – Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
EXCLUSIONS
• Utility Design
• Coordination with LADWP
• Geotechnical Engineering
• Signage and striping
• Parking lot design
• Parking/traffic Studies
• Traffic engineering
• Design of facilities outside of the project site
• Legal descriptions, government fees, permits and assessments • Preparation and approval of plans for work within the public right-of-way • Construction staking
• Bid and Construction Support Services
• Permit Processing
• Design of fence walls
• Water quality monitoring
• Assembly, advertisement, and distribution of bid package • Fire department coordination
• Preparation or revisions to a SWPPP
• Environmental evaluations or report
• Submittal to, review by or coordination with LA County • Preparation of any hydrologic analyses or reports
• Preparation of a CLOMR/LOMR and its associated fees and coordination with FEMA • Other analyses not explicitly described herein.
EXHIBIT “A”
SCOPE OF SERVICES
Proposal for Professional Engineering Services
Haskell Canyon – Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
ASSUMPTIONS
• The Project Limits identified on Exhibit “A-1”, attached are approximate and based on the previous discussions with the city. The project limits shall be verified with the city prior to the start of work and the scope of services and fee schedule presented herein shall be adjusted as needed to accommodate changes to the project limits.
• No provisions have been made for permitting or processing plans through the City of Santa Clarita, Los Angeles County, or any other agency. It is assumed that the city will review the plans internally and Psomas will address minor plan check corrections. • Changes in design precipitated by the city will be addressed for an additional fee. Changes in design due to normal design coordination are anticipated and included in this proposal. Revision of documents at city direction when such revisions are inconsistent with previous approvals or direction, including adjustments made necessary by adjustments in city’s budget or program, or by major unforeseen field conditions will be addressed for an additional fee. • A geotechnical report will not be given to Psomas for geotechnical recommendations of the paving section and Arizona crossing walls. Psomas will use available standards and best engineering judgment for the design of the improvements.
SCHEDULE “A”
FEE SCHEDULE
Proposal for Professional Engineering Services
Haskell Canyon - Arizona Crossings
Santa Clarita, CA
Psomas Proposal No. 26-0460R1
June 12, 2026
Client agrees to pay Consultant as compensation for the professional services described in Exhibit “A” in accordance with the below schedule.
Description Budget
Basic Services
Surveying Services (fixed fee) $ 17,300
Hydraulic Analysis (fixed fee) $ 16,700
Arizona Crossing Design (fixed fee) $ 24,000
Specifications and Engineer’s Estimate $ 4,000
Meetings and Coordination (fixed fee) $ 5,000
TOTAL FEE $ 67,000
• Services will be performed in accordance with the provisions of our current agreement of which Exhibit “A” and Schedule “A” will become part.
• The attached Hourly Rate Schedule is valid through December 31, 2026.
• This proposal is valid for period of 90 days, after which, consultant’s proposed fees will be revaluated.
2026 FEE SCHEDULE
Los Angeles and Santa Clarita Offices
Engineering , Land Use Entitlements, and Surveying
IN-OFFICE SERVICES
Effective from January 1, 2026 - December 31, 2026
Administrative/Project Administrator $110 - $150
Drafter/Design Drafter $130 - $160
Civil Engineering Designer/Engineer $130 - $160
Surveyor/Project Surveyor/GIS Specialist/Photogrammetrist $115 - $190 Planners/Assistant Planner/Expeditor/Senior Planner $125 - $205 Project Designer/Professional Engineer/Project Engineer $160 - $190 Sr. Project Engineer/Sr. Project Surveyor/Sr. GIS Specialist $185 - $235 Project Management $185 - $295
Principal/Director $250 - $350
SURVEY HOURLY RATES - FIELD SERVICES
Effective from October 1, 2025 – September 30, 2026
One-Person Survey Party $240
Two-Person Survey Party $400
Three-Person Survey Party $530
Hourly rates for field survey parties include normal usage of field equipment and are fully equipped rates. Per Diem is calculated at current State Department of Transportation rates (or other appropriate Agency rate).
REIMBURSABLES
Mileage at current IRS allowable rate and parking expenses incurred by office employees are charged at cost.
Prints, plots, messenger service, subsistence, air travel, and other direct expenses will be charged at cost plus ten percent. The services of outside consultants will be charged at cost plus fifteen percent.
The above rate schedule is for straight time. Overtime will be charged at 135 percent of the standard hourly rates. Work performed on Sundays and holidays will be charged at 170 percent of the standard hourly rates.
Billing Policies and Procedures
The relationship with our client works best when there is a mutual understanding about fees and payment terms. You are encouraged to discuss with us any questions you may have concerning these policies.
Billing
The value of our services is determined primarily by the time spent on each client matter.
Our time records are kept on a weekly basis and invoices are prepared every four or five weeks, depending on our accounting calendar.
Payments
As there is a time lag between rendering professional services and mailing our bills, all invoices are due upon presentation. Any bills that are not paid within thirty days are classified as “delinquent,” and a late charge of 1-1/2 % per month will be added.
Work Stoppage
Work will be stopped on any job that has invoices outstanding for more than 60 days .
Due to the costs and inefficiencies that results from stopping and restarting a job, an additional “start-up charge” will be assessed.
Retainers
It is our policy to obtain an advance retainer from all new clients and from exiting clients under certain circumstances. Also, it occasionally may be appropriate to require an advance retainer after the commencement of a project or to require an increase in a prior retainer. This depends in part on our client’s payment history and the scope of the work involved.
Reimbursable Expenses
Costs, other than time charges, are based on usage. Therefore, the cost of blueprinting, messenger service, transportation, and other specific job related costs are charges as “reimbursable expenses.” Generally, these are a very small portion of the total cost of a project. If requested, we will provide a computer printout which details these costs. We do not provide any additional backup for these generally nominal expenses.
PSOMAS
Nick Tarditti, CFA
Chief Financial Officer
EXHIBIT A-1
AREA 1
AREA 2
CROSSING 1
WORK LIMITS
CROSSING 2
WORK LIMITS