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Surface and Groundwater

Hydrogeologists and Geotechnical Engineers – Lost Without Translation [906 KB]

P J N Pells and S E Pells

Impacts of Longwall Mining and Coal Seam Gas Extraction on Groundwater Regimes in the Sydney Basin Part 1 – Theory [939 KB]

Due to a communication mishap the versions of this paper and the following as published did not include the final proof corrections by the authors. The versions provided here include those corrections.

S E Pells and P J N Pells

Impacts of Longwall Mining and Coal Seam Gas Extraction on Groundwater Regimes in the Sydney Basin Part 2 – Practical Applications [1.60 MB]

S E Pells and P J N Pells

The Critical Importance of Extreme Events in Relation to Water Resources [4.38 MB]

A generally relevant extract from a review of the Wallarah 2 longwall mine EIS.

Three Dimensional Groundwater Model of Hume Coal Prospect, Southern Highlands NSW [12.2 MB]

S E Pells and P J N Pells

CSG – Some Knowns and Unknowns – Science Forum, State Parliament House, 25 March 2014 [2.29 MB]

P J N Pells

Impacts from Coal Mining at Springvale Colliery on the Temperate Highland Peat Swamps of the Newnes Plateau [14.5 MB]

This is a report prepared for the Colong Foundation and the Blue Mountains Conservation Society and is placed here with their permission.

S E Pells

The Water Levels Of Thirlmere Lakes – Where Did The Water Go, And When Will it Return? [5.75 MB]

This paper presents the methodology and findings of an independent study into the declining water levels of five unique freshwater bodies, known collectively as the ‘Thirlmere Lakes’, NSW Australia.

P J N Pells and S E Pells

Desktop Estimation of Yield for Aquifer Storage Recovery Schemes

To be successful, Aquifer Storage Recovery (ASR) or managed aquifer recharge (MAR) schemes must solve the significant timescale differences between surface water flows and groundwater flows – it becomes a juggling act trying to get the surface water into and out of the ground quickly enough to match the vagaries of surface water flows and user demands.  Analysis of this can be done at a desktop level and provides insight into the feasibility of the proposed scheme, and an estimation of the yield – ie how much water are we actually going to make?  This paper sets out some of this way of thinking. 

SE Pells

Application of Dupuit’s Equation in SWMM to simulate baseflow

SWMM is a very useful coupled hydrology/hydraulic model, and comes for the right price, but its completely uncapable of simulating non-urbanised catchments unless you include its groundwater modules.  The documentation for the model doesn’t give great guidance for how to use these modules.  I developed a technique to my satisfaction and published it for my own posterity.  I still use the paper often, although I’m not sure if anyone else does ;). 

SE Pells and PJN Pells

Placed Rock as Protection against Erosion by Flow down Steep Slopes – PEIRSON, W L, FIGLUS, J, PELLS, S E and COX, R J 2008

A large flume apparatus was set up to test the stability of rip-rap scour protection when placed on steep slopes and subject to flows.  The findings from this testing were published in the attached paper. This has since been an ongoing area of interest to me, I furthered the research in a chapter of my PhD, and in the ‘discussion’ paper below.  More to come on this topic …

DISCUSSION on the paper: “Evaluation of Overtopping Riprap Design Relationships” by Steven R. Abt, Christopher I. Thornton, Bryan A. Scholl, and Theodore R. Bender – discussion by SE Pells and WL Peirson.

Numerous methods for estimation of stability of rockfill under flows have been published, and the paper by Abt et al compiled and reviewed 21 of them.  I contributed a short discussion because in my snooping I found that almost all the published methods used the same freebody, and more importantly, the freebody is wrong – this became evident when trying to reconcile it against the ‘infinite-slope’ solution used in the geotechnical sector.  

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