We evaluate the return on investment (ROI) from public land conservation in the state of Minnesota, USA. We use a spatially-explicit modeling tool, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), to estimate how changes in land use and land cover (LULC), including public land acquisitions for conservation, influence the joint provision and value of multiple ecosystem services. We calculate the ROI of a public conservation acquisition as the ratio of the present value of ecosystem services generated by the conservation to the cost of the conservation. For the land scenarios analyzed, carbon sequestration services generated the greatest benefits followed by water quality improvements and recreation opportunities. We found ROI values ranged from 0.21 to 5.28 depending on assumptions about future land use change, service values, and discount rate. Our study suggests conservation is a good investment as long as investments are targeted to areas with low land costs and high service values.

Irrigated row-crop agriculture is contributing to declining groundwater in areas such as the Mississippi Delta region of eastern Arkansas. There is a need to move toward sustainable levels of groundwater withdrawal. Recent improvements in remote monitoring technologies such as wireless soil moisture sensors and unmanned aerial vehicles offer the potential for farmers to effectively practice site-specific variable-rate irrigation management for the purpose of applying water more efficiently, reducing pumping costs, and retaining groundwater. Soil moisture sensors and unmanned aerial vehicles are compared here in terms of their net returns per acre-foot and cost-effectiveness of aquifer retention. Soil moisture sensors ($9.09 per acre-foot) offer slightly more net returns to producers than unmanned aerial vehicles ($7.69 per acre-foot), though costs associated with unmanned aerial vehicles continue to drop as more manufacturers enter the market and regulations become clear.

An irrigated agricultural landscape experiencing groundwater overdraft generates economic returns and a suite of ecosystem services (in particular, groundwater supply, greenhouse gases reduction, and surface water quality). Alternative land cover choices indicate tradeoffs among the value of ecosystem services created and the economic returns. These tradeoffs are explored using efficiency frontiers that determine the least value in ecosystem services that must be given up to generate additional economic returns. Agricultural producers may switch to irrigation with surface water using on-farm reservoirs and tail water recovery systems in response to groundwater overdraft, and this has consequences for the bundle of ecosystem service values and economic returns achievable from the landscape. Planning that accounts for both ecosystem service value and economic returns can achieve more value for society, as does the adoption of reservoirs though lowering the costs of irrigation, increasing groundwater levels, and reducing fuel combustion and associated GHG emissions from groundwater pumping. Sensitivity analyses of per unit value of ecosystem services, crop prices, and the groundwater and water purification model parameters indicate tradeoff among ecosystems service values, such as the use of a high-end social cost of carbon ultimately lowers groundwater supply and water purification value by more than 15%.

Valuation of water in an aquifer depends on reliable information about the hydrologic conditions of an aquifer. Regions of depression emerge in an aquifer because groundwater cannot seamlessly flow between shallow and deep aquifer locations, and our analysis shows that the degree of lateral flow influences the value of the water in the aquifer. The assumption that groundwater declines uniformly over a landscape, a bathtub aquifer, leads to an underestimate of the value of a unit of water in an aquifer but an overestimate of the wealth that the aquifer represents. For the alluvial aquifer in Arkansas, USA, the average accounting price of water in an aquifer is almost 40% higher if there is no lateral flow, but the groundwater wealth is 10% lower. The value of an aquifer with the limited lateral flow is less sensitive to changes in agricultural markets, the discount rate, or the natural recharge of the aquifer.Recommendations for Resource Managers Average value of water in an aquifer with limited lateral flows is nearly 40% higher than the value of an aquifer with high lateral flows. Groundwater wealth weights the accounting prices of water in the aquifer by the amount water underneath each site. As lateral flows decline, the wealth of the aquifer rises and then falls because the distribution of accounting prices change so most water is beneath sites with lower accounting prices. The average value of water in an aquifer is less sensitive to changes in hydro‐economic model parameters such as the natural recharge or discount rate when the lateral flows are less.

Two approaches to augment irrigation water supply are managed aquifer recharge (MAR) and on‐farm reservoirs with tail‐water recovery (OFS‐TWR). We explore the joint use of MAR and OFS‐TWR to sustain groundwater and agricultural income with climate variability by farmer risk preference. We find that MAR use declines slightly with greater risk aversion and declines rapidly with MAR cost. The use of OFS‐TWR increases with risk aversion. The use of MAR increases income by a larger percentage for risk‐neutral than very risk‐averse producers. Across risk aversion degree, the use of MAR leads to a percentage increase in income that is double the percentage increase in the standard deviation of income (i.e., income risk). At a low cost of MAR, there is little difference in MAR use between a very risk‐averse and a risk‐neutral producer across scenarios of crop profit margin and the initial depth to water. Large differences in OFS‐TWR use between a very risk‐averse and a risk‐neutral producer occur when there are relatively high crop profit margin, low initial water depth, or a low discount rate.