This invited presentation will focus on the role of fungi in the transport of water between soil and plants. The importance of mycorrhizal fungal to water uptake and transport is an important question for agriculture and wildland restoration. Potentially, mycorrhizal fungal hyphae connect roots to the soil surface, reducing the gaps formed as roots shrink, and provide bridges to water transport. The hyphae also bridge the gaps across soil spaces as the soil water potential drops below saturation. In some cases, rhizomorphs comprised of mycorrhizal hyphae extend well beyond the plant canopy for several meters. Other hyphae form dense networks of from 50 to 100m per g soil. Hyphae also penetrate rock matrices, sources of water during drought. Finally, hyphae are recipients of hydraulically-lifted water, stimulating fungal nutrient absorption during dry-down periods. Dye transport experiments have shown that the pathways between soil and plant root are present allowing for water exchange. Field experimental studies indicate that mycorrhizae maintain a plant's positive water balance and sustains fungi activity in dry soils. However, the relative fluxes and amounts remain unclear. Glasshouse experiments are inconclusive because the experimental conditions themselves dictate the outcomes. Calculations show different outcomes, depending on the structure of components of the system. Currently, we are designing an array of sensors linked to minirhizotron to actually observe, monitor, and measure water and nutrient dynamics in situ. The goal of this research is to take the range of possible responses that theory generates, and determine which variables become important as conditions vary spatially and temporally. We also intend this discussion to stimulate new uses and approaches to field measurement at micro-scales necessary to resolve the role of fungi in water flows and plant water relations.