SESSION 6A GEOPHYSICS AND REMOTE SENSING

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1 SESSION 6A GEOPHYSICS AND REMOTE SENSING

2 NASA MODIS Flood Mapping Product Data Assimilation to Improve Soil Moisture Estimates in the Real-Time Prediction of Flash Flooding Ari Posner, Eylon Shamir and Konstantine P. Georgakakos Hydrologic Research Center Surface soil moisture is a principal variable in estimating the rainfall-runoff relationship in a given catchment, and is paramount in developing reliable flash flood warnings. Antecedent soil moisture conditions impact the ability of additional precipitation inputs to infiltrate, rather than becoming runoff. NASA Office of Applied Science is producing an experimental product from the satellite-based MODIS instrument detecting standing water, daily at 250m resolution. In lowland areas and flat terrain, inundation persists after precipitation as the result of backwater effects from swollen rivers or raised regional groundwater levels. Such phenomena cannot be simulated with local catchment modeling, but satellite-based observation may provide information useful to adjust such models. Conceptual hydrologic models represent depth-integrated soil moisture, as a set of depth-layered water storage reservoirs with certain volumetric capacity to infiltrate and store water. Given that a portion of the catchment area is inundated, the total volume of the upper soil can be divided in to two separate volumes, inundated and not. MODIS observations may then be used to update the inundated portion of the total volume at the time of observation, thereby updating the water volume in the upper soil zone. The differences between data-assimilated soil moisture estimates and model results were normally distributed. Random generated numbers from the statistical moments of the model error for each catchment were used in ensemble forecasting of runoff prediction. The results show that data-assimilated soil moisture estimates increased the likelihood that bankfull flow would occur at catchment outlets for many late season storm events.

3 FAQs about Groundwater Geophysics Norman Carlson, Zonge International, Inc. Philip Sirles, Zonge International, Inc. What s the success rate? Why didn t it work on my project? What are the valid groundwater applications of the different geophysical methods (resistivity, seismic, radar, CSAMT, etc.)? What does the geophysical data actually show? The use of geophysics in the groundwater industry has increased in recent years, and is likely to continue increasing as both drilling costs and water users climb. Though its use is more common in the hydrocarbon and minerals industries, problems and questions remain about the proper application of various geophysical methods to groundwater projects. Ranging from groundwater exploration to recharge studies to mapping acid mine drainage, this presentation will use case histories of both successes and failures to address the most frequently asked questions about geophysics and groundwater projects.

4 SESSION 6C EFFLUENT REUSE

5 Energy Requirements for Recycling Water Resources in Tucson Maya Teyechea, Asia Philbin Tucson Water, Tucson, Arizona Tucson Water, the largest municipal water provider in southern Arizona, is evaluating multiple options to optimize water-resource use. Tucson s effluent entitlement has been underutilized in the community to date. With uncertainties regarding future shortages to the Colorado River, recycling of treated wastewater is rapidly becoming a major water resource focus across the western United States. However, recycling of resources requires energy for both treatment and conveyance. Tucson Water and the Pima County Regional Wastewater Reclamation Department are designing and will construct a reclaimed water recharge facility in southeastern Tucson. The South Houghton Area Recharge Project (SHARP) will recharge reclaimed water during periods of low demand from re gular customers. Reclaimed water is produced at the Tucson Reclaimed Water Treatment Plant on the west side of the City. Specific energy requirements were evaluated for transmission of the reclaimed supply to recharge for future use.

6 The Once and Future River Anticipated Change in the Effluent-Dependent Lower Santa Cruz River Evan Canfield 1 Akitsu Kimoto 1 James DuBois 2 Julia Fonseca 3 Brian Powell 3 Jacob Prietto 4 Pima County is in the midst of a $670millon project that will significantly improve water quality discharged to the effluent-dependent Lower Santa Cruz River, which is expected to also improve habitat. The County recently was awarded an EPA Grant to monitor changes in the river and report these to the public in a series of Living River annual reports. In support of this effort, we prepared the Historical Conditions of the Effluent-Dependent Lower Santa Cruz River. This Report compiles and interprets existing data on water quantity, flow regime and geomorphology, vegetation, water quality, and macroinvertebrates; as well as describing changes we expect to see from improvement in water quality of the discharge. The most dramatic impacts are likely to result from decreased nutrient load. Infiltration rates are expected to increase as biofilms forming the clogging layer become less pervasive. The vegetation distribution may change in response to these changes in infiltration, and some plants, such as nitrophobic forbs, may become more abundant as water quality improves. Finally, treatment plant upgrades are expected to improve aquatic habitat, which will enhance the food web and provide improved conditions for wildlife. In summary, the Historical Conditions of the Effluent-Dependent Lower Santa Cruz River provides a better understanding of current river dynamics, and describes possible changes in river functions in response to imminent water quality improvement. This presentation will summarize some of the findings from the report and describe the anticipated changes following the treatment plant upgrades. Affiliations 1 Pima County Regional Flood Control District 2 Pima County Regional Wastewater Reclamation Department 3 Pima County Office of Sustainability and Conservation 4 University of Arizona, Department of Hydrology & Water Resources

7 Doug McMillan 2013 AHSS Abstract - CSI September 6, 2013 Controlled Sewer Inflow (CSI) The purpose of the following summary is to describe the concept of increasing groundwater recharge in aquifers experiencing declining groundwater levels by the controlled discharge of harvested rainwater from impervious surfaces into existing sanitary sewer facility systems. Sanitary Sewer Infiltration-Inflow Most sanitary sewer systems in the United States have some level of measureable infiltration-inflow in their collection systems. Infiltration is the relatively slow introduction over a prolonged period of time of rainwater or snow melt into sanitary sewer pipes and manholes with leaky cracks and joints. Inflow is the relatively fast introduction over a shorter period of time of rainwater through direct means such as roof downspout connections to sewer laterals. In general, the older the sanitary sewer system then the more infiltration. Some cities and districts (over 722 in the US) have intentional discharge of storm water into sanitary sewer systems. These combined sewer systems are mostly older systems that were not upgraded to separate systems because of prohibitive costs. Infiltration-inflow is generally considered undesirable to have in sanitary sewer systems because of the possibility of combined overflow discharges of wastewater and storm water to the environment. In addition, the resulting increased hydraulic loadings can result in increased capital, operation and maintenance costs. Rainwater Harvesting Arizona has recently been considering the water resource alternative of harvesting rainwater for supplemental groundwater recharge. This concept is given various names one of which is macrorainwater harvesting (MRH). In the Prescott, Arizona area, MRH has been a recent topic of discussion which has lead to the consideration of related State legislation, a legislative study committee and a planned pilot study. In addition, MRH has been included as one of several other water resource alternatives in the Bureau of Reclamation Central Yavapai Highlands Water Resource Management Study (CYHWRMS). MRH will be relatively expensive due to the need to construct, operate and maintain new rainwater harvesting, transport and recharge facilities. These costs represent the cost of groundwater sustainability which is in addition to the present costs of pumping, storing, transporting and distributing groundwater. The most significant MRH cost component is the collection and transport of harvested rainwater from areas with minimal or no groundwater recharge potential to areas with relatively high groundwater recharge potential. Implementation and Benefits of Controlled Sewer Inflow (CSI) The concept of CSI is to use existing sanitary sewer infrastructure to collect and transport harvested rainwater to an acceptable groundwater recharge site rather than installing new infrastructure. This assumes that the existing treatment plant is already discharging effluent to a relatively permeable area. 1 of 3

8 Doug McMillan 2013 AHSS Abstract - CSI September 6, 2013 CSI could be considered a sub-alternative to MRH because the primary difference between these two concepts is the method of collection and transport. The existing sanitary sewer infrastructure used for this purpose would include collection, transport, pumping, storage, treatment and recharge facilities. The key word that differentiates this concept from unintentional infiltration-inflow is "controlled". CSI would involve the release of harvested rainwater at the most hydraulically advantageous times to prevent hydraulic overload of the sanitary sewer facilities. The reason why this concept can be implemented is that wastewater and infiltration-inflow flow rates vary with time. Wastewater flow rates will consistently follow the same pattern over a 24 hour period (diurnal). Domestic wastewater flow peaks can occur mostly in the early morning hours before people leave their homes and in the evening hours after they return. The wastewater flow rates will be minimal during the night time hours when people are sleeping. Commercial and industrial wastewater flow rates will follow a different pattern. As the result of indirect travel paths to the sanitary sewer system, infiltration will slowly increase with time after a rainfall event occurs, reach a maximum and then gradually subside depending on the amount of rainfall and the duration of the rainfall event. As a result of direct connections to the sanitary sewer system, inflow can increase rapidly after the start of a rainfall event, reach a relatively high peak and then quickly decrease after the rainfall event ends. CSI involves storing harvested rainwater from impervious surfaces near its source and only discharging it to the sanitary sewer system when wastewater and infiltration-inflow flow rates are relatively low to minimize hydraulic loadings. Harvested rainwater could be stored and released by private property owners and public entities. Storage facilities could include tanks or basins. Control mechanisms would need to be designed to maximize operational reliability and ease of use and minimize maintenance. Depending on the rainwater harvesting surface, pre-treatment may be required before discharge to the sanitary sewer system. At the wastewater treatment plant, operators could use flow equalization facilities to vary the proportion of wastewater and rainwater volumes for the optimal performance and hydraulic loading to the various treatment facility components. Depending on water quality source controls, organic and solids loadings in the harvested rainwater should be low or insignificant. Therefore, organic and solids loadings at the treatment plant influent should be relatively unchanged. The end result of this control strategy is to: 1) have more effluent volumes available for groundwater recharge to offset groundwater pumping, 2) decrease potential contaminate loadings into urban watersheds and 3) decrease rapid runoff and the potential for erosion in local tributaries. See the following hydrograph and conceptual schematic for further information. 2 of 3

9 Doug McMillan 2013 AHSS Abstract - CSI September 6, 2013 Doug McMillan is a retired civil environmental engineer living in Prescott, Arizona. 3 of 3