| Popis: |
Public awareness of the problems associated with erosion, such as sedimentation and loss of capacity ofdrainageways or undesirable sediment deposits on roads and public and private property, has increased in recentyears. To address this, communities nationwide, particularly larger communities (population over 100,000), haveadopted stormwater regulations requiring use of sediment controls or best management practices on constructionsites and other disturbed areas. Frequently, design of these controls is done using rules of thumb or tradition,without assessing their effectiveness for the particular situation.Effectiveness of a control is commonly determined by either a water quality design standard or a performancestandard. For sediment control, a water quality performance standard dictates a maximum acceptable level ofsediment in the effluent. The control is designed such that this concentration is not exceeded. On the other hand, awater quality design standard establishes a standard pond design based on a given drainage area or similar criterion.For this work, structure trapping efficiency (TE) was selected as the performance standard. This paper describesdevelopment of design aids for a specific jurisdiction, then extension of that methodology to one that can be appliednationwide. Sediment ponds with riser of weir outlets will be covered here. Similar work has also been completedfor rock ditch checks and rockfill outlet ponds. |
