BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

This infiltration trench collects sheet flowing stormwater off the edge of a driveway and isbordered with larger stones.3.4.4 STORMWATER COLLECTION AND CONVEYANCECollection and conveyance techniques may be necessary to capture runofffrom impervious areas and direct it to infiltration and/or treatment BMPs.Sediment Traps (Refer to Chapter 4 BMP Toolkit, Section 4.4.2.6) are neededat the end of all conveyance systems prior to infiltration BMPs to promotelongevity and ease of maintenance. Table 3-4 provides guidance for commoncollection and conveyance systems.Table 3-4: Stormwater Collection and ConveyanceHANDBOOKSECTIONStormwater Collection andConveyance(Section 4.3)APPLICABLE BMPSLess than orEqual to 5%SlopeCOMMON RUNOFF CONVEYANCE SYSTEMSGreater Than 5%SlopeNotesSlotted Channel Drain(Section 4.3.1.7) x xThe discharge point of all conveyanceA/C Swale(Section 4.3.1.8)xSubsurface Drain(Section 4.3.1.9) x xRock Lined Swale(Section 4.3.1.10) x xVegetated Swale(Section 4.3.1.10)xsystems to infiltration systems arerequired to have a Sediment Trap(Section 4.4.2.6)Used for higher runoff velocities andsteeper slopes.Not applicable over 6% slope. Use checkdams for vegetated swales over 3%slope. Refer also to Check Dam (Section4.1.2.2)TRPA BMP HandbookCHAPTER 3: Permanent BMP Planning and Selection2012 Page 3-9