Two US geologists say leave Managaha alone

Two US Geologists have warned the CNMI against constructing a seawall, revetment or any form of protection on Managaha island to prevent soil erosion because it will only lead to the destruction of the beach area.

The advise came from Robert Mullane, a Coastal Geologist, University of Hawaii and Bruce Richmond, Coastal Geologist, USGS during a recent workshop held here attended by environment and local officials.

Instead of building any structure that would save Managaha island from further eroding, the two geologists said they should simply allow nature to take its course. Constructing a seawall or revetment in one area will protect the land behind it but such action may lead to further erosion and destruction of the beach area as the strong waves would just pull the sand away from the wall, according to Peter Barlas, acting director, Coastal Resources Management.

“By allowing the natural processes, nature will reach its natural equilibrium and stabilize itself,” said Barlas. He said CRM shares the view of the two US Geologists to leave Managaha island alone.

Based on the 1992 photo taken by Richmond, the Garapan shoreline was severely damaged by soil erosion at that time. Today, the beach area has fully recovered, partly due to some measures taken by CRM.

In fact, both Richmond and Mullane noted that Saipan is much better than any other island in the Pacific because sand excavation and coral mining, are not practiced here. Furthermore, there has not been any proliferation of seawall or revetment on the island compared to other areas in the Pacific.

“We are very happy to hear that the CNMI is in pretty good shape compared to other islands in terms of coastal erosion and proliferation of seawalls,” Barlas said.

In fact, Barlas said CRM will no longer allow the repair of the seawalls and retaining walls constructed in a beach area in San Antonio once these are damaged by storms.

A study made by a coastal engineer showed that a seawall or revetment built in one area would affect the adjacent property since it would only speed up the erosion there.

A Lagoon Use Management Plan undertaken by Duenas and Associates, Inc., in cooperation with Dr. Steven S. Amesbury, a marine biologist, said the CNMI government must establish a development policy for Managaha island to maximize its tourism potential and ensure environmental protection.

Improvements and design on Managaha island should be built for long-term use and must be approved by Northern Marianas government.

The study added that an Environmental Impact Assessment must be made to determine the maximum daily visitor rate for Managaha since they affect the underwater resources by diving and snorkeling in nearby waters.

Based on the 1996 visitor count, some 340,000 tourists visited the island. Overnight, non-commercial camping and or public education should be allowed. Restroom should be open for 24-hour use, the master plan said.

Tourists are ferried daily to Managaha where they can swim and snorkel the whole day. A day trip to the island can cost around $60 which include the use of facilities.