Grassed Waterway-1

ILLINOIS PRACTICE DOCUMENTATION REQUIREMENTS

GRASSED WATERWAY (412)

  1. GENERAL

Minimum documentation requirements for this practice are outlined below. Documentation for associated practices or system components shall follow the appropriate practice documentation requirements.

  1. References
  2. National Engineering Manual (NEM)
  3. Illinois Field Office Technical Guide (FOTG)
  4. National Engineering Handbook (NEH), Part 650, Chapters 2, 3, and 7
  5. Minimum NRCS Waterway (EFH Chapter 7, IL EFM Notice 3, pages IL 7-48 through IL 7-50)
  6. SCS-TP-61, “Handbook of Channel Design for Soil and Water Conservation”
  7. Agricultural Handbook 667, Stability Design of Grassed-lined Open Channels (ARS)
  8. Conservation plan for the unit
  9. Computer software – Illinois waterway design spreadsheet, others
  10. Local supplemental criteria
  1. RESOURCE INVENTORY AND SURVEYS
  2. Design Investigations
  3. Number and reach
  4. Drainage area (ac)
  5. Average watershed slope (%)
  6. Runoff Curve Number
  7. Hydraulic length
  8. Allowable velocity (ft/sec) based on soil type
  9. Location of underground utilities
  10. Locations of waterway inlets and outlets considering erosion, sedimentation, and drainage laws
  11. Design Surveys
  12. Design surveys may be combined with layout surveys, dependent on the judgement and experience of the responsible designer.
  13. Minimum Waterway Designs
  14. Surveys for channel grade are not required.
  15. Waterway Designed Individually
  16. Surveys of waterway channel grade every 100 ft are required.
  17. Benchmarks description, location, and elevation or rod readings.
  18. Cross sections or low bank/ control elevation shots at a minimum of every 300 ft.

  1. Field survey notes will conform to NEM Part 540 and follow standard field note documentation as illustrated in Technical Release 62 (TR-62). Survey notes will be prepared such that they exhibit legible, logical, clear and concise data.
  1. Environmental Inventory
  2. NEPA inventory of resources -- form CPA-52 must be completed by NRCS during planning
  3. Wetland effects, if applicable
  4. Archeological/Historical/Cultural Resources (if needed) – This will be consist of a completed “Cultural Resource Review Form” that had been submitted. This will include a copy of the responses from the cultural resource specialist confirming the status of the site.
  1. DESIGN
  2. Design data, provide printout from software or document data from design charts
  3. Hydrologic data -- peak design flows for each reach, including documentation of drainage area and data used to determine peak flow.
  4. Hydraulic determinations -- design velocities for each reach based on soils and vegetal retardance conditions.
  5. Required dimensions and capacity for each reach.
  6. Description of temporary or permanent erosion control structures to be installed.
  7. Quantity and cost estimates.
  8. Seeding requirements and area to be seeded.
  9. Legal description.
  10. Initials/signatures and dates by the person(s) responsible for the design, approval, and checking of the design.
  11. Permits and Approvals
  12. 404 permit (if applicable) -- document if individual permit was obtained, nationwide permit applies, or if practice is exempt.
  13. County or local permits if applicable.
  14. PLANS AND SPECIFICATIONS
  15. Plans
  16. Use appropriate “D” or “B” sized sheets.
  17. Plan view -- may be superimposed on location map. Show stationing and benchmarks. Include map orientation and benchmark descriptions and elevations.
  18. Profile -- centerline of waterway. Show original ground superimposed on design, grade, stationing, reaches, etc. Centerline profiles are required on waterways as needed. Determination is based on judgment of person with Job Approval Authority.
  19. Cross-sections -- plot cross-sections for each reach as needed. Determination is based on judgment of person with Job Approval Authority.

  1. Construction notes -- add notes to clarify a component and furnish directions for installation to supplement standard specifications as needed.
  2. Construction plans shall include a statement requiring the contractor to notify the Illinois One-Call System (JULIE) regarding utilities on the construction site. See the General Documentation Requirements section of the Illinois Practice Documentation Requirements Manual for the recommended statement.
  3. Add notes as necessary to identify avoidance and, if needed, protection of areas and boundaries associated with cultural resources, threatened or endangered species, or other resources needing temporary protection during installation.
  4. Table of quantities.
  5. NRCS Engineering Job Class.
  6. Location map with legal description.
  1. Specifications
  2. Illinois FOTG Conservation Practice specifications, component specifications from NEH Part 650, Engineering Field Handbook Appendix 1, or equivalent, modified as needed. Additional specifications may be written to provide full material and installation instructions.
  3. O&M Plans
  4. As specified in Illinois FOTG.
  5. Plans, Specifications, O&M Plans Delivery
  6. Case folder
  7. Transmittal letter copy
  1. LAYOUT
  2. Layout Surveys – can be combined with design surveys
  3. Use field notebook, forms, etc.
  4. Minimum Waterway Design
  5. Identify alignment of waterway for construction purposes.
  6. Individual Waterway Design
  7. Record in field notebook or on forms.
  8. Reference stakes or slope stakes at each reach to control alignment and grade as designed.
  9. Set stations at an interval based on the judgment of the technician with Job Approval Authority. Recommended maximum interval – 200 feet.

  1. COMPLIANCE CHECKING
  2. Record in field notes.
  3. Length, width, depth, and side slopes (trapezoidal) or quarter points (parabolic). Individual design waterways require a minimum of one cross-section per design reach.
  4. Statement on temporary or permanent erosion control measures installed.
  5. Status of seeding.
  6. Construction inspection report.
  7. Statement of compliance - statement that construction is completed according to plans and specifications, signed and dated by the person certifying completion.
  8. “As Built” Plans
  9. Refer to NEM, 512.51 and 512.52
  10. “As Built” plans are a record of constructed facilities. “As Built” plans are required when a significant change in design occurs during construction or when the job is designated Class V or higher. Changes are superimposed in a different color (usually red), or differentiated in some other manner (such as a drawing a box around the as-built value) on the official file copy and show:
  11. Significant[1] design changes.
  12. Significant1 changes in linear measurement.
  13. Final quantities -- may be based on layout stake notes, if no changes were approved and work meets planned lines and grades.
  14. Identify as “As Built” on plans.

(IL-PDRM, June 2003)

[1]Determination of "significant" is a matter of judgment by the technician. As a general rule, changes that exceed normal measuring error allowances, normal construction tolerances, and methods of mathematical computation, should be considered as significant.