concept EIA-rapport - Staatsolie

SRK Consulting: Project No: 439414 Staatsolie Pipeline EIA – Draft EIA Report Page 27
The sediment load of the Suriname River from terrestrial runoff used to be relatively low at an
estimated 250 000 tons per year (NEDECO 1968). It has further decreased since the construction of
the Afobaka Dam in 1964, which created the Brokopondo Reservoir (officially known as the Prof. Dr.
Ir. W.J. van Blommesteinmeer) and traps most of the upriver sediments. The current supply of
terrestrial sediment to the estuary consists mostly of fine sediments transported as suspended load.
Sand is found upriver of the study area, south of Paranam, where it occurs as sand banks. All river
sediments in the area are of Holocene age.
The record of a drinking water well at Peperpot (in Meerzorg, opposite the Staatsolie refinery) shows
a 33 m thick clay layer, overlying alternating layers of coarse sand and clay. The clay in the upper
33 m ranges between soft and firm, with the firm material located at a depth of between 12 and 21 m
(SWM, unpublished data). Figure 4-4 shows an example of a half ripe (in between soft and firm) clay
of the upper 1-2 m of the river bottom in front of the refinery.
Figure 4-4: Suriname River clay bottom sediment taken nearshore at the Staatsolie refinery
Source: Dirk Noordam (2012)
4.1.2.2 Geomorphology
Four major geographical zones can be distinguished in Suriname, shown in Figure 4-5:
1. The Holocene Young Coastal Plain formed on sandy and clayey marine deposits. This plain is
flat to nearly flat and very low-lying. It is characterized by extensive wetlands;
2. The Pleistocene Old Coastal Plain, like the Young Coastal Plain, formed on sandy and clayey
marine deposits. This plain is low-lying and flat to very gently undulating. The plain is alternating
with deep swamps of the Early Holocene Mara Formation;
3. The Zanderij or Savanna Belt formed on Late Tertiary braided river deposits. This belt forms an
undulating to rolling lowland plateau, which is characterized by localized patches of savanna;
and
4. The Precambrian Guiana Shield area, commonly also known as the Interior.
REUT/DALC 439414_StaatsoliePipelineEIA_Draft EIA Report_Final June 2012