Who Gains from and who Pays for Channel Deepening?

Abstract

Port dredging to accommodate larger vessels can create substantial national economic benefits. However, how affected individual states fare economically with dredging is often unclear and can be an important issue. The benefits and the costs to Delaware residents of dredging—with the recent proposed deepening of the Delaware Bay and River main federal channel as a case study—are examined. Benefits include (a) lower transportation costs that residents might receive on imported goods, (b) profits that residents would realize if cost savings (e.g., on refinery products) were not passed forward to Delaware users, (c) project costs that residents would bear as federal taxpayers, and (d) benefits that residents would realize if the use of dredged sediments for planned beach renourishment created savings to the state. Sensitivity analyses are used to reflect uncertainty in outcomes. The estimated net present value to Delaware today of all future annual quantifiable benefits and costs ranges between $15,528,393 and $14,195,700 over 50 years at 5.875%. Stated another way, the quantified net benefits for Delaware imply a benefit-cost ratio between 2.07 and 1.89. Hence, for every dollar of the $7.5 million that Delaware would pay as a nonfederal cosponsor, estimated quantifiable net benefits to the state are $2.07 to $1.89. Some benefit and cost estimates are vehemently debated between interested parties, and not all benefits and costs can be quantified.