3000 SR 529 2016-01-01 MF Import

BMP C130: Surface Roughentng Purpese Surface roughening aids in the establishment of vegetative cover, reduces runo(T'velocity, increases infiltration, and provides for sediment trapping through thc provision of a rough soil surfacc. Horizontal dcpressions arc crcated by operating a tiller or other suitable equipment on the contour or by Icaving slopes in a roughcncd condition by not finc grading thcm. Conditions jor . All slopcs stecper than 3:l and grcatcr than ��crtical fcct rcquirc Use surface roughening. . Area, with gr.�des stceper than 3: I should bc roughcncd to a Jcpth of 2 to 4 inchcs prior to sceding. . Areas that «�ill not be stabilized i�nmediately may bc rough:ned to rcducc nmoff ��clocity until sccding takcs placc. • Slopes with a stable rock face do not requirc rouehcnine. . Slopes where moa�ing is planned should not bc e�ccssi��cly roughened. Dasign and �ihere are different methods for achieving a roughcned soil surface on a !nsla!lafinn slope, and the selection of an apprupriatc method depends upon the typc of Specifrcarions slopc. Rougheninc methods include stair-step gradin�, grooving, contour ftirrows, and tracking. Scc Figurc 4.6 for tracking and contour furrows. Factors to be considered in choosing a method are slope steepness, mowing rcquircmcnts, and whcthcr thc slopc is Comied by cuuing or filling. • Disturbed areas that will not requirc mo�ving may be stair-step Graded. grooecd, or Icft rough alicr filling. . Stair-step gr�ding is particularly appropriate in soils containing large amounts of sofl rock. Each "sicp" catchcs matcrial that sloughs from ahove, and pravides a Icvcl sitc whcre vcgctation can become cstablishcd. Stairs should bc �+•idc cnough to ��•ork with standard catth moving equipment. St�ir steps must be on contour or gullics ��ill forni on thc slopc. . Arcas that will he mowed (these arcas shnuld have slopes Icss steep �han �:I ) moy ha��c small furrows icti by disking, harro��-ing, raking, or sccd-planting nmchincry operatcd on thc contour. . Gradcd :ircas µ�ith slopcs gre:ucr than 3: I but Icss than 2:1 should bc rou�nencd bcfore sccding. lhis can bc accomplishcd in a varicry of aays, including „track walking." or driving a crawlcr trictor up and do�vn the slopc. IL`8�9OS' e�1:1��1'Ill OiCII`H� II11�7fIIli5 j78leIICI 10 SI0�1C COI110Ufti. .'I'r�cking is donc by openling equipment up anA down Ihc slope to Icavc horizonlal dcpressions in thc soil. Alainlenaucc • Arcas th�n arc graded in Ihis maimcr should bc sccdcd as quickly as Smndurds possiblc. . Rcgular inspeclions should bc madc of thc :uca. If rills nppcar, thcy should be re•�raded and ro-secdcd immediately. 4•36 Volume ll — Construc(ion Stormwafer Pollufion Prevenfion February 2005