Issue: Corrective Action: Preventative Action: Eroded inflow apron. Repair apron. Routine inspection and rehabilitation, if necessary. Issue: Corrective Action: Preventative Action: The vegetation loss and the blackish soil may indicate frequent inundation. Check the permeability rate of the soil and the water table elevation. Replace the soil if necessary. Routine inspection and tilling/aeration, if necessary. Issue: Corrective Action: Preventative Action: The low flow channel has excessive accumulation of sediment and debris. The outflow orifice is clogged by a trash bag and debris. Note that there is no trash rack installed. Check the permeability rate of the soil and the water table elevation. Replace the soil if necessary. Routine inspection and cleaning. Issue: Corrective Action: Preventative Action: Trash rack is damaged. Repair the trash rack. Routine inspection, especially after large storm events. Tighten any loose bolts and repair structural flaws. A well maintained detention basin Reference Documents Documents to be placed in this field manual should include the following: As-built Drawings with Drainage Plans Soil Boring Logs Landscaping Plan Liner Specifications and Maintenance Manual
For Inspector For Maintenance Crew Component No. Component Name Inspection Item and Inspection Item No. Result Preventative / Corrective Maintenance Actions A1 Pretreatment (Forebay) 1 Scouring or erosion is present at inlet structure and/or riprap apron Y__ N__ Check the flow diversion device before the inlet pipe and whether the bypass flow channel is clogged Work Order # __________ 2 Clogged pipes or excessive sediment in the forebay Y__ N__ Remove sediment or debris 3 Damaged outlet structure (e.g., cracking, subsidence, spalling, erosion, or deterioration) Y__ N__ Repair or replace the outlet structure Work Order # __________ A2 Pretreatment (MTD, if installed) 1 MTD inspection Y__ N__ (If a MTD is used for pretreatment, see manufacturer’s maintenance manual) A3 Pretreatment (Structural BMP) 1 BMP inspection Y__ N__ (See BMP No. ________ Field Manual) Note:
B Basin Bed 7 Animal burrows/rodents are present Y__ N__ Pest control Work Order # __________ 8 Liner of the basin is visible and/or is damaged (if applicable) Y__ N__ Repair or replace liner Work Order #__________ C Vegetation 1 Large spot(s) showing bare soil Y__ N__ Vegetative cover must be maintained at 85%. Revegetate the entire basin if 50% or more vegetation has been lost Check Landscaping plan for guidance (if available) Work Order # __________ 2 Overgrown vegetation Y__ N__ Mow/trim the vegetation Work Order # _______ 3 Tree growth in the basin Y__ N__ Clear, trim, or prune the trees according to the original Landscaping Plan Inspect to determine if the tree roots caused any structural damage Work Order # __________ Note:
D Basin Embankment and Side Slopes 1 Signs of erosion, soil slide or bulges, seeps and wet spots, loss of vegetation, or erosion on the basin slope Y__ N__ Check for excessive overland runoff flow through the embankment. Check for any sink hole development Direct the overland runoff to the forebay or pretreatment area Restabilize the bank Work Order # __________ E Outlet 1 Trash or debris accumulation more than 20% Y__ N__ Clean and remove Determine source of trash and address to reduce future maintenance costs or basin failure 2 Trash rack is damaged or rusted greater than 50% Trash rack is bent, loose, or missing parts Y__ N__ Repair or replace trash rack Work Order #__________ 3 Outlet components (e.g., orifice plates or weir plate) skewed, misaligned, or missing Y__ N__ Repair or replace component Work Order #__________ 4 Discharge pipe apron is eroded or scoured Y__ N__ Restabilize the discharge riprap apron Work Order #__________ 5 Standing water is present in the outlet structure longer than 72 hours Y__ N__ Pump out the standing water Work Order # __________ Note:
F Emergency Spillway 1 Trees or excessive vegetation present Y__ N__ Remove trees and roots, and restore berms if necessary Work Order #________ 2 Damaged structure Y__ N__ Repair Work Order #________ G Miscellaneous 1 Fence: broken or eroded parts Y__ N__ Repair or replace Work Order #__________ 2 Gate: missing gate or lock Y__ N__ Repair or replace Work Order #__________ 3 Sign/plate: tiled, missing, or faded Y__ N__ Repair or replace Work Order #__________ 4 Excessive or overgrown vegetation blocking access to the basin Y__ N__ Clear, trim, or prune the vegetation to allow access for inspection and maintenance Work Order #________ Note: