​© Copyright 2014 CCIL Mining & Mineral Resources

Mindanao River & Marine Sand Dredging Project-

Simuay River, Sultan Kudarat, Maguindanao

River Sand

Marine Sand

Early this year, the LGU of the Municipality of Sultan Kudarat, the Honorable Mayor Shameem Mastura and CCIL Mining & Mineral Resources Corp (CCIL) initiated and signed a MOA on a flood mitigating project called- “Dredging & Re-alignment of the Simuay River”. CCIL was granted Resolution 19-04 interposing no objection to the project and Resolution 19-05 authorizing Hon. Mayor Mastura to enter into a MOA with CCIL. Barangay Sembolawan also issued CCIL Resolution 02-2019 also interposing no objection to the project. CCIL as the “Grantor” of the project , appointed JMI as the “Implementor” of the flood mitigating project. JMI was appointed as implementor of the project since we have all of the local permits and licenses and the most qualified entity to implement the project. The company is also registered with the Regional Board of Investments (RBOI), wherein the said project has been published as the First Investment registered under the Bangsamoro Organic Law (BOL).

 

As a backgrounder, JMI Sand and Gravel & Trucking Corporation (JMI) has been doing business which involved the extraction of sand & gravel since 2012. JMI was granted thirteen (13) Environmental Compliance Certificates (ECC’s) and Industrial Sand and Gravel (ISAG) Permits to quarry sand and gravel along the Simuay River supplying domestic market in western Mindanao.

Marine Sand Coordinates- Phase I

Topographic Map of Sultan Kudarat, Maguindanao showing the Phase I Dredging Project along the coastline of Simuay River.

Topographic Map of Sultan Kudarat, Maguindanao showing the Phase II Dredging Project along the Simuay River.

River Sand Coordinates- Phase II

Abstract

Simuay River and Coastline Dredging Project area is located in the Municipality of Sultan Kudarat, Province of Maguindanao. The project area covers the shoreline along the mouth of the Simuay River that extends to about 5.4 kilometers of coastline from Simuay Seashore to the mouth of the Rio Grande River (Mindanao River) down to Timako Hill . It also covers the Simuay River stretching from its river mouth to about 20 kilometers upstream covering about 4 barangays. The primary purpose of this project, which consists of dredging the deposited coarse sand at the Simuay river mouth is the deepening and aligning of the Simuay river in order to address and lessen the periodic flooding and bank erosion within the area. Simuay River measures ranges from 40-150 meters in width whereas the actual floodplain ranges about 600-700 meters wide. 

The primary objective of the dredging project is to address or significantly lessen the flooding within the Municipality of Sultan Kudarat in Maguindanao. Simuay River is the main cause of flooding within the project area during abnormal precipitation and typhoons causing floods in several barangays. Phase I dredging along the coast will open up the heavily silted mouth of Simuay River blocking the outflow of river water onto the open sea. Phase II of the project involves river dredging and channel re-alignment of the Simuay River. Dredging will deepen the riverbed thus increase water containment whereas re-alignment will move the thalwegs  to the central sections of the river thus reducing bank erosion. This project is considered a strategic mitigation measure to control and reduce flooding. Research studies from several countries indicated that dredging is the ultimate solution to totally eliminate or significantly reduce flooding. Sheet piling and concreting of embankment are considered temporary protection of river banks but does not decrease or lessen flooding.

Exploration and Bathymetric Survey

A semi-detailed geological survey of placer sand and gravel deposits of Simuay River and along the shoreline between Panalisan and Banilisan Point of Barangay Inawan and Sambolawan  The primary objective of this geological survey are to establish the stratigraphic rock units, gather geologic structures, mode of occurrence, and their origin and to evaluate whether the lower Simuay river and shoreline marine sands have sufficient sand & gravel resource for local and overseas market.

The surveyed area is drained by the colossal south-southwest flowing Simuay River and its numerous tributaries that discharge their loads directly to Iliana Bay of the Sulu Sea. The meandering Simuay River is characterized by broad flood plains with steep banks and the presence of lensoidal sand bars indicating a matured stage of geomorphic development of the area. Due to constricted nature of some sections along the upstream portions of the Simuay River, the great volume of sediments carried by floodwaters were deposited along the downstream section of Simauy resulting in the formation of fan-shaped delta deposit wherein the water flows in different directions developing braided river channels.

The survey area covering the municipalities of Sultan Kudarat and Sultan Mastura, is chiefly underlain by different stratigraphic units that tentatively exhibit a sequence of decreasing age as follows: 1) clastic rocks- sandstone, shale, siltstone, conglomerate, 2) limestone- coralline, 3) volcanic flows- basaltic to andesitic, and 4) recent alluvial deposit. The older clastic sedimentary sequence which covers a major part of the mapped area is underlain by gently folded, alternating beds of shale, siltstone, sandstone and conglomerate. Unconformably overlying the clastic sedimentary sequence are isolated bodies of massive coralline and fossiliferous limestone probably deposited under shallow marine environment. This limestone is well-exposed along the barangay road in Barangay Balut, Polloc Island and within the Cotabato City proper. Outcropping along the road-cut in Brgy. Balut, the limestone possibly occurs as an erosional remnant since they appear to occupy the hilltops. Several huge clams (taklobo) were collected by local residents from different locations most likely extracted from the limestone formation. This massive and bedded limestone varies in color from buff to light brown color and characterized by cavities and fractures lined with calcite crystals exhibiting a tooth texture. Intruding the older folded and rhythmic sequence of clastic shale, siltstone, sandstone, and conglomerate are isolated basaltic volcanic plugs exposed at the tip of the east-west trending Polloc Island of Parang and Timako Hill west of Cotabato City. The volcanic plugs are composed of massive, dark grey to black, amygdaloidal basaltic to andesitic flows with abundant vesicles commonly filled with clay and calcite. Fractures and weathered surfaces are limonite-hematite stained.

The recent alluvial deposits which occupy the flat-lying areas along the flood plains and the delta are mainly composed of well-rounded, unconsolidated to semi-consolidated materials of variable sizes and shapes consisting of clay, silt, sand, pebble, gravel, and cobble. These are derived from the extensive weathering, disintegration and erosion of the pre-existing host sedimentary rocks within the drainage basin.

An echo sounding survey was conducted along the Simuay cut-off canal in Barangay Sembolawan, part of the Rio Grande River, along the coastline from Panalisan Point to Polloc Port using a Koden Echo Sounding instrument CVS-118Mk II model. In principle, sounding is a type of sonar used to determine the depths of water by transmitting. sound pulses into water the time interval between emission, and return of a pulse is recorded which is used to determine the depth of water along. with the speed of sound in water at the time. A more detailed sounding surveys was implemented within the Polloc port area and at the coast of Simuay River mouth. The main objective of the survey is to determine depths suitable anchorage for dredging and panamax vessels for the proposed dredging project of the Simuay coast as another mitigating measure to control flooding.

 

The echo sounding survey route started from Cotabato City along the Rio Grande River. A fisherman’s boat was used during the survey along Rio Grande towards the sea, then northwards. A separate survey was done from the mouth of the Simuay upstream along the cut-off canal for about 5 kms. Measurements were recorded every 50-100 meters in some sections to have a thorough information on the water depth of the man-made cut-off canal of the Simauy River. Approximate river width was also measured to determine any proposed widening of the canal during the dredging project.

Geological Map of Sultan Kudarat, Maguindanao covering the Dredging Project along Simuay River and shoreline.

Google map imagery showing the echo sounding survey along the coastline of Simuay River in Sultan Kudarat, Maguindanao.

Ocular Investigation & Assessment

Photographs showing the initial ocular investigation of the Simuay River and shoreline in Sultanm Kudarat, Maguindanao

Bathymetric & Exploration Survey

Photographs showing the bathymetric survey, sampling and test drilling of the Simuay River and shoreline in Sultanm Kudarat, Maguindanao