Data: Faster, Cheaper, and Sometimes Better. River restoration projects and research, like all land development projects, rely on topographic data. This has historically come from ground surveys and more recently by remote sensing from manned aircraft that produce digital elevation maps from technologies like LiDAR or Photogrammetry. In terms of applications available today, new methods of remote sensing are providing high resolution datasets at more affordable costs than were possible by previous platforms. These are in newly available software and hardware. 

Software 

The adoption of geomatic technologies (e.g. GPS, LiDAR, etc.) has driven a profound increase in the dimensionality of topographic datasets and used within river science, and geomorphology more broadly. However, recent advances in computer vision and image analysis have led to a novel photogrammetric techniques called Structure-from-Motion (or SfM). SfM is a powerful tool as it has proven an effective tool to generate high-quality topographic elevation models at low-cost. This is exciting because researchers now can adequately and affordable capture terrain evolution over long periods of time, and practitioners have the ability to acquire current and relevant topographic data instead of relying on older datasets. 

Hardware

The most exciting new hardware are definitely Unmanned Aircraft Systems (UAS, UAV, or drones). The adoption of such systems offers affordable and high quality remote sensing. For example, drones have been shown to offer cost-effective solutions for data acquisition of aerial imagery for project base maps as well as the necessary images for SfM. However, these systems are capable of carrying far more than cameras payloads. UAS platforms are extremely exciting because we can now acquire data from various sensors while geo-locating the data (i.e. having GPS tied to individual data measurements). Further, we are seeing a revolution in the reduction of size, weight, and cost of popular sensors. For example, LiDAR is now available for as low as $85,000 (where manned aircraft LiDAR was easily around $1 million) and in complete turn-key packages weighing as little as 2.2 kgs. Thus such package are fully capable to be utilized by UAS platforms.

Each of these advances are now enabling all land development projects the capabilities to capture the data that they need at affordable costs. In turn, this quality data will enable managers the ability to make more informed decisions, higher detailed analysis, and overall better designs for functionality and sustainability.  

Dams. Dams provide essential water supply for communities, but have caused significant river degradation due to interrupted sediment transport, reduced daily flows and periodic flooding, and consequently reduce available habitats for many species. However, smart planning and innovative sediment passage can vastly reduce the impacts. 

Dams by Design, is the Nature Conservancy's approach to "reengineer old dams, remove or avoid others and better plan for those that will occur in the future" and for those that will be constructed, evaluating the "entire river basin and the impacts a dam will have both upstream and downstream" is conducted. Through these approaches, the nature conservancy found that 300,000 kilometers of river could be impacted by future hydropower; however, 100,000 kilometers could remain free flowing if designed appropriately (Rivers and Lakes: Hydropower by Design). Such benefits would drastically reduce the negative impacts, preserve valuable habitat, and through natural healthy rivers, excess nutrients can be further minimized. 

Sustainability is a challenge for dams due to sediment trapping and storing which not only limits the working life of dams, but also starves and degrades rivers' downstream. Therefore, improving sediment transport through the dam, or in some cases around the dam, should be widely adopted. With proactive pre-planning of basin environment considerations, optimal dam site locations, design, and operations, sustainable dams can drastically reduce the environmental degradation and increase the longevity of the dams. Such forward thinking can make dams and reservoir storage capacity "viewed as a renewal resources, with much more positive implications for the future sustainability of water supply and hydroelectric generation" (Sustainable sediment management in reservoirs and regulated rivers: Experiences from five continents). 

Vegetation as Engineers. Native vegetation plays a critical role in the evolution and physical shape and size of rivers. While many native vegetation has been removed from riverbeds, banks, and floodplains, restoration efforts are trying to re-establish such vegetation as a larger restoration project. However, many river restoration projects try to force specific conditions (e.g. a meandering pattern, pool-crest-pool profile, or river bank protection with boulders, etc.), where these 'designs' are often idealized or inappropriate for the hydraulics, morphology, or vegetation. Some new approaches use soft engineering, and rely on native vegetation to naturally help the river evolve into the healthy and sustainable system that the current conditions allow. Such methods simply re-introduce vegetation in appropriate areas (i.e. where the specific vegetation would naturally be found in relation to the river), let the vegetation thrive where the conditions are appropriate, and as a result the vegetation's presence will naturally evolve the river into the shape and size for the given conditions. While this approach is slower to reach aesthetically pleasing rivers, the final result is a river system that evolved to the governing conditions and is often cheaper due to less mechanical excavation and permitting. Further, the introduction of vegetation will have longer lasting eco-improvements, as the vegetation will naturally help filter and remove excess nutrients for the lands prior to entering the river as well as helping remove nutrients from the water. 

Over the last five years, several river restoration organizations have developed insightful tools to help during the process of river restoration. These range from a general lists of what river restoration looks like, to highly detailed step-by-step instructions. The latest is REFORM (REstoring rivers FOR effective catchment Management) which aimed to "improve existing tools and develop new ones to increase the success of cost-effectiveness of restoration measures" (REFORM). While focused on European rivers, the tools can be applied to any river restoration project where the rivers have been impacted by long-term modifications.

What is interesting in REFORM, is that the tool insists, and fully guides the practitioner, on assessing the larger set of spatial and temporal aspects that must be taken into consideration to better understand the current river system and what is reasonable to expect how the river can ‘naturally’ exist given the conditions.

“In assessing hydromorphology, to date there has been too strong a reliance on the reach scale, on the river channel and its current condition, and on focusing on specific river reaches in order to assess rivers, diagnose river problems and design intervention, rehabilitation and restoration measures.”

"The ways in which reaches of different type within a catchment have responded to changes / interventions in the past provides crucial information for forecasting how reaches may change in the future, whether the catchment continues to be used and to function as at present or to be subjected to different scenarios of change." 

This well defined and presented methodology will help all river managers and restoration efforts into greater holistic views of the river systems, and hopefully greater sustainability in river projects.