Delaware Chapter Surfrider Foundation - Indian River Inlet Monitoring

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1 Delaware Chapter Surfrider Foundation - Indian River Inlet Monitoring In 2012, the Delaware Surfrider Foundation Chapter formed the Surf Quality and Access Committee to focus on issues such as surf spot protection, surfing access, and improve surfing opportunities in Delaware. An overall assessment of surfing opportunities in Delaware is available in the State of Surfing in Delaware a report released in January 2014, and available here: One issue the Committee is monitoring is the impact of the 2013 beach replenishment project which was done along the beach north of Indian River Inlet to address impacts from Hurricane Sandy, and longer term erosion issues. Observations have been made at Indian River Northside since the beachfill collecting data and taking photographs to monitor how the surf break recovers from the beach nourishment. The North Side beach fill project began in August 2013 and was completed in October Since a great deal of natural seasonal changes occur at all beaches in Delaware, by October 2014 it may be possible to assess conclusions about the effects of the project on Indian River Inlet. Early 2013 PRE-PROJECT CONDITIONS A large amount of fine-grained sandy material was stockpiled along the beach at the Northside of Indian River Inlet related to the bridge construction project. The pictures below show the piles of material about a month prior to Hurricane Sandy in the process of being moved by wave action into the surf zone: Hurricane Sandy deposited the remainder of this material across Highway one and into the oean feeding a large quantity of fine grained material into the Indian River Inlet surf beach creating good surfing conditions following this storm.

2 Six months after Sandy, good surfing conditions continued at Indian River Inlet northside as the following pictures illustrate: Pre-Beachfill - April 9, flat profile following Hurricane Sandy Pre-Beachfill - April 12, 2013 North Side Indian River Inlet, mid tide 8 Seconds swell

3 Pre-Beachfill - April 8, 2013 North Side Indian River Inlet, low tide Swell 8 seconds swell August October 2013 INDIAN RIVER INLET NORTHSIDE BEACHFILL Between August and October 2013, approximately 520,000 cubic yards (COE estimate) of sand was dredged from the flood shoal of Indian River Inlet and placed on the beach north of Indian River Inlet after the COE determined that no action would create a high probability for loss of the beach and infrastructure. An overview of the project is available in the Finding Of No Signficant Impact document (FONSI) available here: %20March%2025%20revision.pdf The FONSI (page 30) also contains a statement concerning anticipated impacts of the project on recreation and surfing: 6.7 Recreation Impacts to recreation in the area will be moderate to severe during construction, but short term in nature. Fishing from the jetty will be temporarily impacted due to construction activity. Beach goers who utilize the beach north of the jetty for recreation will need to relocate as sands are distributed and the dune system is rebuilt. Sand distribution and dune rebuilding take place during daylight hours when tides allow and it is unsafe for recreational enthusiasts to be in close proximity to the equipment being used to conduct such work. To minimize construction hazards, beachfill segments are typically fenced off to the public in sections of about 1,000 ft. Once the beachfill operation in a segment is completed (typically in 1-2 weeks), the fencing is removed, and recreational activities may resume. The addition of sands to the beach will also impact artifact collectors that use this area for the collection of colonial half pennies. This area is also known as coin beach and regularly draws enthusiasts looking for the coins. Surfing is a popular activity in this area. Surfers will not be impacted by construction activities other than accessing the beach as the nature of surfing leaves surfers in the off shore environment. It is worthy of note that there is a concern for the potential to affect the surf break on the north shore. Based on the quantities of sand to be placed and the method of placement, a temporary shore break may

4 exist within this area immediately after construction. However, this shore break is expected to adjust and flatten out as the waves and currents re-shape the beach profile. This is supported by the fact that the construction template will not exceed previous beachfills in the area, and that the grain sizes of the beachfill (fine to medium sands) will favor a flatter beach profile. Based on the time constraints allotted for the project and the time frame given for completion, impacts to recreation will be short term and have no long term effects. Beach fill operations at Indian River Inlet in August of 2013 approximately 100 feet north of the Inlet Jetty On October (see picture below) a moderate non-tropical coastal affected Delaware creating the first high energy conditions. Beachfill had been completed over the southernmost 2000 feet of the project (representing the surfing area) by the time this storm hit. The waves in the photo are 5-6 feet medium period wind-driven waves with a

5 northeast angle. A significant quantities of sand was redictributed in by this storm and carried out into the nearshore ocean bottom. The breaking waves in this photograph are approximately feet from the beach. Post-Beachfill October 30, 2013 North Side Indian River Inlet, low tide swell 9 seconds In the photograph above, taken 2.5 weeks after the early October coastal storm, 2 foot waves are breaking about 75 feet off the beach in the vicinity of the Indian River inlet north jetty. The beach fill was largely complete at this time. The nearshore profile in this photograph indicates a moderate shoreline profile in the vicinity of the jetty which was conducing to surfing.

6 Occasional surfable conditions returned to Indian River Inlet within months of the 2013 beachfill project. Delaware Surfrider Chapter believes that a major factor was utilizing finer grain sand from the Inlet. The Army Corp. contractor shared sand sampling data as the project progressed northward of the jetty. The Delaware Chapter of SRF believes this is a positive sign that warrants additional research by the Army Corps. This is significantly different than other communities such as Bethany Beach and Rehoboth Beach where surfable conditions have for the most part never returned even years after initial beach fill. The steep post-nourishment beach slopes that have prevented surfing in other communities in Delaware are also linked to surf zone injuries. The improved surfable beach at Indian River Inlet is also a more swimmable beach due to its flatter slope and waves breaking further offshore.

7 Post Beachfill June 2014 North Side Indian River Inlet, medium tide 8 seconds of swell Post - Beachfill - August 26, 2014 North Side Indian River Inlet, medium tide 8 seconds swell

8 December 31, 2014 Status and Conclusions. The north side of Indian River Inlet remains surfable as of the end of 2014 over a year following the 2013 beach fill at Indian River Inlet. The large quantity of sand place on the beach by the U.S. Army Corps of Engineers in 2013 clearly had an impact on the surfing quality, but those effects have been mixed. At times in 2014, the beach slope appeared to steepen, nearshore water depths became greater and waves broke closer to the beach limiting surfing potential. At other times the slope became flatter and waves tended to break further offshore improving surfing conditions. Surfing conditions over the past year seemed to generally be better closer to the North inlet jetty, and were less often surfable in the Cove a frequently surfed area about feet north of the inlet. The DNREC sand-bypassing which began operation in September 2014 seemed to have an effect on the surf break as sand is released into the intertidal zone and affecting beach slope. The effects of the sand bypassing system on the surf breaks on both sides of the inlet have been a subject of much debate for years and since both sides of the inlet are popular surf spots, the impacts of the sand bypassing system on surfing should be explored further. The DE SRF hopes that the by-pass system can be operated in a way that preserves the surfing breaks on both sides of the inlet. Shortly after completion of the beachfill project in 2013 the Corps of Engineers also hired a company to perform repairs to the north inlet jetty. These repairs were intended to block voids in the jetty that were allowing sand to pass from the beach side into the inlet. This project and the retention of sand that it supports appears to have positive effect on the surf break by limiting the loss of sand from the beach slope of jetty area. The Delaware Surfrider Chapter believes monitoring and evaluation is needed at Indian River Inlet to better understand the movement of sand and how the beach and surf breaks are impacted. Given the cost of the 2013 beachfill project, the impacts of storms and erosion to the highway and the serious nature of the inlet jetty deterioration, and by-passing system, continued monitoring is warranted to improve the stability of the inlet and adjacent beaches. Finally, the Delaware Chapter SRF communicated safety concern of concrete slabs exposed on the north side of the Inlet, possibly related to work repairing the jetty. The photograph below shows rocks and concrete exposed in August of These rocks and concrete debris could pose a threat to beachgoers, swimmers and surfers, as they become submerge or move around.

9 Delaware sand migration is south to north, the construction of the IRI jetties in 1938 interrupted the long shore drift of sand along Delaware's coast line. While south side IRI receives accumulation of sand the northside of IRI is starved of sand creating significant erosion. While the northside surfing area has received periodic beach replenishment since 1957, beginning in 1991 the Sand by-pass operation was established to offset the interruption of sand transport on a yearly basis. Studies of northside erosion rates over the last 30 years, the ranges of erosion can vary from 5' to 14'. These deficiencies and challenges continue to plague coastal managers and threated the northside designated surfing beach. The August 2013 beach fill has provided some success by providing protection while without as severe an impact to surfing as might have happened. A major factor of this restoration was the use of finer/medium grain sand from the IRI inlet shoals over past beach replenishment practices of coarser material observed along the Delaware coast line. The post beach fill photographs demonstrate the finer sand forming necessary sand bars shortly after the project was completed. The 2013 Northside beach fill Army Corp. contract established a 1-10 (1 foot drop for every 10 feet) of beach slope profile. While this 1-10 foot slope is the common standard that is applied to Delaware beach replenishment projects. The DE SRF Chapter has been studying other projects in New Jersey where a much flatter slope (1-20) was applied to Long Beach Island. The surfing amenity recovered very quickly rather than prior estimates of 1 or 2 years, if at all. The flatter beach profiles eliminate steep beach drop offs safety issues currently under study in Delaware by allowing the wave to break further off the beach and rolling to the shore line. A phenomena was investigated in 2013 on northside, about 1500 (unclear exactly where) feet north of the north side jetty is a "nodal" point south of which sand is flowing southerly along the beach back to the jetty and seaward around the jetty tip. The "nodal point" study is not complete and conclusion of the "nodal" point should may be known by the end of 2015 and could aid in the management of this system. The Army Corp. completed a repair to northside jetty from the end of the side walk about 200 feet to the wash zone. The side walk as well as the jetty had sunken, compromising integrity to hold and retain sand in this vital area. The repair has been successful as the sand loss adjacent to the jetty has been reduced. The further need is for the Army Corp. to finally address repairs to the remaining portion of north side jetty. The NS jetty has loss nearly 400 feet of its original length. Previous scientific studies have concluded the jetty is losing on average 4' per year and this data has not been disputed by the Army Corp. The inlet side of NS jetty near the jetty tip has scour holes in excess of 50 feet below the jetty foundation that further jeopardizes the jetty's integrity. A question remains if the existing jetty seaward portion is salvageable and, if not, should a new jetty be considered. Now that the "nodal" point has been studied, has the loss of NS jetty length played a role in sand migrating around the jetty tip into the inlet? It is our belief addressing NS jetty and hopefully its restoration will play a major role stabilizing northside designated Surf Beach long term and provide stability to this vulnerable and dynamic area. In conclusion, restoring surf amenities to Delaware Beaches is a daunting and difficult task. The Delaware SRF Chapter is committed to monitoring this location and communicating with coastal managers. While we're realizing some success with NS IRI with use of finer grain sand the future application of flatter beach slope would offer remedies of safety concerns of current beach break adding more desirable surf zone recreation for swimmers and surfers.