People just keep publishing interesting stuff.

Fiorillo, F. 2009. Spring hydrographs as indicators of droughts in a karst environment. Journal of Hydrology 373: 290-301.

Rosenberry, D.O. and J. Pitlick. 2009. Effects of sediment transport and seepage direction on hydraulic properties at the sediment–water interface of hyporheic settings. Journal of Hydrology 373: 377-391.

Gresswell, R. et al. 2009. The design and application of an inexpensive pressure monitoring system for shallow water level measurement, tensiometry and piezometry. Journal of Hydrology 373: 416-425.

Fryar, A.E. 2009. Springs and the Origin of Bourbon [Historical Note], Ground Water, 47(4): 605-610.

Cardenas, M. Bayani. 2009. Stream-aquifer interactions and hyporheic exchange in gaining and losing sinuous streams Water Resour. Res., Vol. 45, No. 6, W06429

Selker, John; Ferre, Ty P. A. 2009. The ah ha moment of measurement: Introduction to the special section on Hydrologic Measurement Methods Water Resour. Res., Vol. 45, No. null, W00D00

Hodgkins, Glenn A. 2009. Streamflow changes in Alaska between the cool phase (1947-1976) and the warm phase (1977-2006) of the Pacific Decadal Oscillation: The influence of glaciers Water Resour. Res., Vol. 45, No. 6, W06502

Matott, L. Shawn; Babendreier, Justin E.; Purucker, S. Thomas Evaluating uncertainty in integrated environmental models: A review of concepts and tools Water Resour. Res., Vol. 45, No. 6, W06421

Orr, Cailin H.; Clark, Jeffery J.; Wilcock, Peter R.; Finlay, Jacques C.; Doyle, Martin W. Comparison of morphological and biological control of exchange with transient storage zones in a field-scale flume J. Geophys. Res., Vol. 114, No. G2, G02019

Katsuyama, Masanori; Kabeya, Naoki; Ohte, Nobuhito Elucidation of the relationship between geographic and time sources of stream water using a tracer approach in a headwater catchment Water Resour. Res., Vol. 45, No. 6, W06414

Phillips, J.D. 2009. Landscape evolution space and the relative importance of geomorphic processes and controls. Geomorphology, 109:79-85.

And last but not least:

Pretty much all of: Hydrological Processes, Special Issue: Hyporheic Hydrology: Interactions at the Groundwater-Surface Water Interface. Issue Edited by Stefan Krause, David M. Hannah, Jan H. Fleckenstein. Volume 23, Issue 15, 2009.

Most especially this article:
Boano, F., Revelli, R., and Ridolfi, L. 2009. Quantifying the impact of groundwater discharge on the surface-subsurface exchange, Hydrological Processes, 23(15): 2108-2116.