Nonpoint Source Success Story Commonwealth of Northern Mariana Islands Implementing Best Management Practices and a Conservation Action Plan Helps Restore the Laolao Watershed

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Implementing Best Management Practices and a Conservation Action
Plan Helps Restore the LaoLao Watershed
Waterbody Improvsd ^r'ie '-ao'-ao watershed is ori the island of Saipan within the
Commonwealth of the Northern Mariana Islands (CNMI)
archipelago. LaoLao was first included on the Clean Water Act (CWA) section 303(d) list of impaired
waters for failing to support the Recreational and Aquatic Life use designations (UD) in 2004 due to
water quality standard (WQS) exceedances for bacteria. Sedimentation was also noted as a potential
problem in the CNMI 1998 CWA sections 305(b) and 303(d) Water Quality Assessment Integrated
Report (IR). Implementing roadway best management practices (BMPs), along with community-
based restoration activities and outreach has improved water quality in the LaoLao watershed. For
this reason, LaoLao was removed from the list of impaired waters for the Recreational UD in the
2016 IR.
Problem
The 1,043-acre LaoLao watershed includes 4.6 miles
of ephemeral streams that merge and then flow into
LaoLao Bay (Figure 1). The watershed has 1.2 miles of
beach and 2.1 miles of shoreline. In the mid-1990s,
man-made and natural brush fires in the upper
badlands led to significant erosion and consequent
sedimentation in LaoLao Bay (Figure 2). Concerns
about the Bay's diminished water visibility and coral
conditions were reported to CNMI natural resource
agencies by divers and fishermen.
The CNMI Bureau of Environmental and Coastal
Quality (BECQ) monitors two LaoLao Bay sites and six
additional reef flat sites for Enterococci, salinity, plH,
temperature, dissolved oxygen (DO) and turbidity.
These data are used to evaluate water quality and
effectiveness of the restoration activities cailed for in
the LaoLao Bay Conservation Action Plan (CAP). The
CAP was developed in 2009 as a cooperative effort
between community members, organizations and
CNMI resource agencies. A CAP is an alternative resto-
ration approach In CNMI to foster community steward
ship to improve water quality when total maximum
daiiy loads (TMDLs) have not been developed.
LaoLao was first included on the CWA section 303(d)
list of Impaired waters in 2004 for failing to sup-
port the Recreational and Aquatic Life UD due to
WQS exceedances for the fecal indicator bacteria,
Figure 1. The LaoLao Watershed is on the island of Saipan.
Enterococci. Over 10 percent of the samples taken
from the two beach monitoring sites per annum
resulted in public beach advisories due to high bacteria
levels. However, the six reef flat sites that are within
walking distance of the beach sites rarely exceed the
WQS. As the area is not densely populated and has
no sewer system, the source of the exceedances was
theorized to be due to sediment from eroding bad-
land soils and the secondary cross-island coral road
that contains naturally occurring Enterococci that are
known to survive in tropical soils, rather than actual
fecal contamination.
Legend
c= Lidar "streams"
im Watershed Boundary
Surveyed Streams
b Beach Monitoring Sites
^ Badlands
LaoLao

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