Rickson, RJ 2012, 'Evaluating the effectiveness of geotextiles for slope erosion control in mine restoration', in AB Fourie & M Tibbett (eds), Mine Closure 2012: Proceedings of the Seventh International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 101-113, https://doi.org/10.36487/ACG_rep/1208_11_Rickson (https://papers.acg.uwa.edu.au/p/1208_11_Rickson/) Abstract: Mining activities are associated with some of the highest sediment production rates ever recorded. Erosion rates of 100–500 t ha-1 y-1 have been recorded on unconsolidated mine spoil where rill and gully erosion takes place. Disturbed slope forming materials, over-steepened/over-lengthened slopes and lack of vegetation affect hydraulic conditions, generating runoff and accelerating the detachment and transport of slope material. Sediment delivery to watercourses affects water quality (in terms of turbidity and chemical concentrations), causing detrimental effects on aquatic ecosystems. Establishing an effective vegetation stand may take several seasons, especially given the erodible and erosive conditions found on mine sites. Rolled erosion control products (geotextiles) can be used in particularly high risk areas, to control erosion rates significantly, so creating a stable environment for vegetation establishment, and long term reclamation of disturbed sites. Taking a geomorphological approach, this paper sets out to examine how geotextile properties affect the mechanics of erosion processes at the sub-process scale. The aim is to present a methodology for comparing the effectiveness of different products, then linking this to geotextile properties and the underlying geomorphological processes operating. Performance data are used to identify the salient properties of erosion control geotextiles in terms of reductions in runoff and sediment production. Results show that different products (e.g. natural versus synthetic; surface versus buried installation; woven versus non-woven) perform to varying degrees, depending on the storm characteristics (intensity of rainfall) and erosion processes operating (rain splash versus runoff erosion). Significant correlations were found between product effectiveness (sediment control) and area of geotextile (%); depth of flow (mm); geotextile induced roughness (expressed as the Manning’s n roughness coefficient); water holding capacity (%); geotextile weight (g m-2); and geotextile wet weight (% of dry weight both after 24 hours and after 48 hours). However, the following properties were unrelated to product performance: cost of geotextile ($ m-2); flow velocity (m s-1) mean yarn diameter (mm); tensile strength (kn m-1); and geotextile thickness (mm). Understanding how geotextile properties affect erosion control performance helps end users specify cost effective products. Also, manufacturers can use this knowledge to improve the design of new erosion control products.