Stormwater pond/ wetland - construction inspection checklist
Stormwater pond/ wetland - construction inspection checklist.
Link to this table
To access an Excel version of form (for field use), click here.
| Project: | ||
| Location: | ||
| Site Status: | ||
| Date: | ||
| Time: | ||
| Inspector: | ||
| Construction Sequence | Satisfactory/Unsatisfactory | Comments |
|---|---|---|
| 1. Pre-Construction/Materials and Equipment | ||
| Pre-construction meeting | ||
| Pipe and appurtenances on-site prior to construction and dimensions checked | ||
| 1. Material (including protective coating, if specified) | ||
| 2. Diameter | ||
| 3. Dimensions of metal riser or pre-cast concrete outlet structure | ||
| 4. Required dimensions between water control structures (orifices, weirs, etc.) are in accordance with approved plans | ||
| 5. Barrel stub for prefabricated pipe structures at proper angle for design barrel slope | ||
| 6. Number and dimensions of prefabricated antiseep collars | ||
| 7. Watertight connectors and gaskets | ||
| 8. Outlet drain valve | ||
| Project benchmark near pond site | ||
| Facility location staked out | ||
| Equipment for temporary de-watering | ||
| Temporary erosion and sediment control in place | ||
| 2. Subgrade Preparation | ||
| Area beneath embankment stripped of all vegetation, topsoil, and organic matter | ||
| 3. Pipe Installation | ||
| Method of installation detailed on plans | ||
| A. Bed preparation | ||
| Installation trench excavated with specified side slopes | ||
| Stable, uniform, dry subgrade of relatively impervious material (If subgrade is wet, contractor shall have defined steps before proceeding with installation) | ||
| Invert at proper elevation and grade | ||
| B. Pipe placement | ||
| Metal / plastic pipe | ||
| 1. Watertight connectors and gaskets properly installed | ||
| 2. Anti-seep collars properly spaced and having watertight connections to pipe | ||
| 3. Backfill placed and tamped by hand under “haunches” of pipe | ||
| 4. Remaining backfill placed in max. 8 inch lifts using small power tamping equipment until 2 feet cover over pipe is reached | ||
| Concrete pipe | ||
| 1. Pipe set on blocks or concrete slab for pouring of low cradle | ||
| 2. Pipe installed with rubber gasket joints with no spalling in gasket interface area | ||
| 3. Excavation for lower half of anti-seep collar(s) with reinforcing steel set | ||
| 4. Entire area where anti-seep collar(s) will come in contact with pipe coated with mastic or other approved waterproof sealant | ||
| 5. Low cradle and bottom half of anti-seep collar installed as monolithic pour and of an approved mix | ||
| 6. Upper half of anti-seep collar(s) formed with reinforcing steel set | ||
| 7. Concrete for collar of an approved mix and vibrated into place (protected from freezing while curing, if necessary) | ||
| 8. Forms stripped and collar inspected for honeycomb prior to backfilling. Parge if necessary. | ||
| C. Backfilling | ||
| Fill placed in maximum 8 inch lifts | ||
| Backfill taken minimum 2 feet above top of antiseep collar elevation before traversing with heavy equipment | ||
| 4. Riser / Outlet Structure Installation | ||
| Riser located within embankment | ||
| A. Metal riser | ||
| Riser base excavated or formed on stable subgrade to design dimensions | ||
| Set on blocks to design elevations and plumbed | ||
| Reinforcing bars placed at right angles and projecting into sides of riser | ||
| Concrete poured so as to fill inside of riser to invert of barrel | ||
| B. Pre-cast concrete structurer | ||
| Dry and stable subgrade | ||
| Riser base set to design elevation | ||
| If more than one section, no spalling in gasket interface area; gasket or approved caulking material placed securely | ||
| Watertight and structurally sound collar or gasket joint where structure connects to pipe spillway | ||
| C. Poured concrete structure | ||
| Footing excavated or formed on stable subgrade, to design dimensions with reinforcing steel set | ||
| Structure formed to design dimensions, with reinforcing steel set as per plan | ||
| Concrete of an approved mix and vibrated into place (protected from freezing while curing, if necessary) | ||
| Forms stripped & inspected for honeycomb prior to backfilling; parge if necessary | ||
| 5. Embankment Construction | ||
| Fill material | ||
| Compaction | ||
| Embankment | ||
| 1. Fill placed in specified lifts and compacted with appropriate equipment | ||
| 2. Constructed to design cross-section, side slopes and top width | ||
| 3. Constructed to design elevation plus allowance for settlement | ||
| 6. Impounded Area Construction | ||
| Excavated / graded to design contours and side slopes | ||
| Inlet pipes have adequate outfall protection | ||
| Forebay(s) constructed per plans | ||
| Pond benches construction per plans | ||
| 7. Earth Emergency Spillway Construction | ||
| Spillway located in cut or structurally stabilized with riprap, gabions, concrete, etc. | ||
| Excavated to proper cross-section, side slopes and bottom width | ||
| Entrance channel, crest, and exit channel constructed to design grades and elevations | ||
| 8. Outlet Protection | ||
| A. End section | ||
| Securely in place and properly backfilled | ||
| B. Endwall | ||
| Footing excavated or formed on stable subgrade, to design dimensions and reinforcing steel set, if specified | ||
| Endwall formed to design dimensions with reinforcing steel set as per plan | ||
| Concrete of an approved mix and vibrated into place (protected from freezing, if necessary) | ||
| Forms stripped and structure inspected for honeycomb prior to backfilling; parge if necessary | ||
| C. Riprap apron / channel | ||
| Apron / channel excavated to design cross-section with proper transition to existing ground | ||
| Filter fabric in place | ||
| Stone sized as per plan and uniformly place at the thickness specified | ||
| 9. Vegetative Stabilization | ||
| Approved seed mixture or sod | ||
| Proper surface preparation and required soil mendments | ||
| Excelsior mat or other stabilization, as per plan | ||
| 10. Miscellaneous | ||
| Drain for ponds having a permanent pool | ||
| Trash rack / anti-vortex device secured to outlet structure | ||
| Trash protection for low flow pipes, orifices, etc. | ||
| Fencing (when required) | ||
| Access road | ||
| Set aside for clean-out maintenance | ||
| 11. Stormwater Wetlands | ||
| Adequate water balance | ||
| Variety of depth zones present | ||
| Approved pondscaping plan in place and budget for additional plantings | ||
| Plants and materials ordered 6 months prior to construction | ||
| Construction planned to allow for adequate planting and establishment of plant community (April-June planting window) | ||
| 12. Final Inspection | ||
| Construction sediment removed from settling basin | ||
| Contributing drainage area stabilized | ||
| Vegetation established per specifications | ||
| Inlet and outlet structures operational | ||
| Comments: | ||
| Actions to be Taken: | ||