DNREC has completed the emergency dredging and beach repair project at the North Indian River Inlet Beach. Approximately 480,000 cubic yards of sand was dredged and used for restoration.

The project focused on strengthening shoreline resiliency and protecting critical infrastructure, like Delaware State Route 1 (SR 1), an evacuation route, from the damaging effects of storm inundation and coastal erosion.

Project Overview

Approximately 480,000 cubic yards of sand was dredged from the Indian River Inlet Flood Shoal and placed on the beach to rebuild up to 5,000 linear feet of shoreline. This volume is 100,000 cubic yards more than originally planned. (See project overview map)

Dredged material was transported via pipeline and screened for munitions and explosives of concern (MEC) prior to placement on the beach. The dune system was restored to an overall elevation of 16 feet by 25 feet wide.

The beach was constructed to an elevation of 9.2 feet, or about 7 feet above the average high tide, and a width extending over 150 feet.

Dredgit Corporation mobilized to the site in November 2024 and completed the final stages of the project in March 2025.  The North Indian River Inlet Beach has reopened to the public as of April 2025.

Historical Conditions

The North Indian River Inlet coastline has a long history of erosion due to construction of the inlet jetties that began in 1928. The jetties were built to stabilize the inlet and improve navigation, but the hard structures interrupt the natural northward flow of sand via the longshore current.

As a result, sand is trapped by the south jetty and accumulates on the updrift (or south) side, creating a larger beach in that area. Consequently, the downdrift (or north) side of the north jetty experiences a lack of sediment supply, leading to erosion.

From 1957 to 1990, over 2 million cubic yards of sand was dredged from Indian River Inlet to maintain the channel and obtain beach fill for the eroding north Inlet beach. In 1990, the U.S. Army Corps of Engineers (USACE) built the Sand Bypassing Facility to continuously pump sand from the south Inlet beach to North Beach via pipeline and was the primary maintenance activity for many years.

The Sand Bypassing Facility became inoperable in 2019. Since then, DNREC has relied on truck-haul sand from inland sources for beach nourishment. Over time, conditions at North Beach have severely deteriorated and adding sand via truck-haul could no longer overcome the rate of erosion.

Dune breaches occurred during March and August of 2024 due to offshore storms. These storms resulted in flooding and closure of the SR 1 northbound lane for several hours as ocean water subsided, and the roadway could be cleared of sand and debris.

North Beach required a large volume of sand delivered rapidly to reconstruct the dune system to a template that would mitigate erosion. Adding 480,000 cubic yards of sand to North Beach between December 2024 and March 2025 significantly bolstered the shoreline and enhanced coastal resiliency.

A second phase of the repair project, led by the U.S. Army Corps of Engineers, is planned for Fall 2025. By implementing a two-phase beach repair project and rehabilitating the Sand Bypassing Facility (expected late 2025), North Beach is expected to be sustained for several years.

Indian River Inlet Flood Shoal

The Indian River Inlet Flood Shoal is a sandy borrow area that was previously used by the USACE in 2013 to rebuild North Beach following Hurricane Sandy.

Topographic survey data showed that nearly 100% of the sand dredged from the flood shoal in 2013 had recovered within four years; therefore, DNREC evaluated the current material as a borrow source for repairing North Beach.

Sediment cores from the Indian River Inlet Flood Shoal were evaluated for grain size and the presence of contaminants (metals, PAHs, PCBs, pesticides and Dioxins/furans) with associated potential toxicity to benthic aquatic life and human health using risk-based assessment methods and the appropriate guideline concentrations.

Laboratory results confirmed sandy material (an average of 96%) and detected a few contaminants in composite samples, but none were found at concentrations that would impact aquatic life or human health if sediments were dredged and used to rebuild North Beach.

Related Topics:  atlantic ocean, beach, dredging, dune, indian river inlet, watershed stewardship, waterways