*3.3. Volumetric Changes*

The calculated sediment volume changes for the northern and the mid sections of the North Captiva Island, between R67–R76 (north), from 2004–2018 are provided in Table 1. The extremely low and negative values of percentage change show the magnitude of erosion from the northern stations. The northernmost section of the barrier island has remained relatively stable since 2004, whereas from R-monuments 71–74, persistent erosion has been observed, as can be seen by the negative percentage change in sediment volume.

**Table 1.** Sediment volume calculations between R-monuments in the northern portion of North Captiva Island for 2004 to 2018. Beach volume change is estimated using a master profile (MP) kept at 2 m below NAVD88 datum.


Percentage change shown in Table 2 shows the large-scale sediment accretion in the southern end of North Captiva island since 2004 (R76–R81). The magnitude of this accretion increases more towards the south, excluding the southernmost station R81. Cumulatively, the breached area received 1,151,899.11 m3 of sediments since the damage it sustained after Hurricane Charley; during 2004–2018. This massive transport of sediments from the north both helped to heal the cut created by Hurricane Charley, along with allowing for the overall expansion of the southern section of the barrier island.


**Table 2.** Sediment volume calculations between R-monuments in the southern portion of North Captiva Island for 2004 to 2018. See Table 1 caption for the master profile (MP) description.
