## 4 Results  
### Case Study  
The Newtown Creek WWTP is taken as an example. The Newtown Creek WWTP, which is operated by the NYC DEP, is the largest in NYC [11]. It was built in 1967 and is located on Newtown Creek along Greenpoint Avenue in Brooklyn. The plant has a total of 88 employees and a design capacity of 310 MGD (1173.35 \(\times\) 10\({}^{6}\) L/day), providing wastewater treatment services for 1,068,012 people on 15,656 acres [11]. It is in sub-basin 133. As shown in Figure 2(a), the area is 5,067,975.8 square meters, including 29,164.3 square meters of bare soil, 582,010.2 square meters of tree canopies, and 375,189.3 square meters of grass. After a rainfall of 10.9 cm/h for 20 min, the flood elevation of sub-basin 133 is 2.4 m (8 ft) (Figure 2(c)). The storm surge brought by a C2 hurricane is 6 to 8 feet (\(\sim\)1.8 to 2.4 m). In this study, these two events and sea level rise of 8.0 ft (\(\sim\)2.4 m) were regarded as events with similar conditions (Figure 2(b)). The rise in the water level they caused was all 8.0 ft (2.4 m), as shown in Figure 2(d). By comparing the percentage of the submerged length of the WWTP and the amount of damage in these three events, it can be judged which one had a greater impact on the plant.  
Figure 4 provides the inundation maps of the Newtown Creek WWTP under similar conditions. According to the inundation map shown in Figure 3 and measuring the outline length of the buildings shown in Figure 4, Table 4 was developed. Table 4 shows the impact of the three events on the WWTP.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Newtown Creek** & **Building** & **Submerged** & **Submerged** & **Submerged** & **Damage (Thousands** \\
**WWTP** & **Perimeter (m)** & **Length (m)** & **Length** & **Depth (ft)** & **of USD)** \\ \hline Storm Surge (C2) & 18,381.72 & 16,934.28 & 92.13\% & 9.65 & 288,000 \\ Rainfall (10.9 cm/h & & & & \\ for 20 min) & 18,381.72 & 624.46 & 3.40\% & 1.31 & 36,000 \\ Sea Level Rise (8 ft) & 18,381.72 & 7014.86 & 38.16\% & 3.81 & 122,400 \\ \hline \end{tabular}
\end{table}
Table 4: Percentage of the submerged length and maximum flood depth for Newtown Creek WWTP and amount of damage in three events.  
\begin{table}
\begin{tabular}{c c c} \hline
**WWTPs** & **Design Capacity** & **HAZUS** \\
**(MGD)** & **Valuation** \\
**(Thousands of USD)** \\ \hline Port Richmond & 60.0 & 200,000 \\ Oakwood Beach & 39.9 & 60,000 \\ Tallman Island & 80.0 & 200,000 \\ Rockaway & 45.0 & 60,000 \\ Jamaica & 100.0 & 200,000 \\ Bowery Bay & 150.0 & 200,000 \\ Hunts Point & 200.0 & 200,000 \\ Red Hook & 60.0 & 200,000 \\ Owls Head & 120.0 & 200,000 \\ Newtown Creek & 310.0 & 720,000 \\ Coney Island & 110.0 & 200,000 \\
26 th Ward & 85.0 & 200,000 \\ North River & 170.0 & 200,000 \\ Wards Island & 275.0 & 720,000 \\ \hline \end{tabular}
\end{table}
Table 3: HAZUS valuation and damage function of 14 WWTPs in NYC.  
Our study showed that the amount of damage caused by storm surge was the largest, followed by sea level rise, and the least amount of damage was caused by high-intensity rainfall. The amount of damage caused by storm surge was 2.4 times greater than that caused by sea level rise, and 27.1 times that caused by high-intensity rainfall. When considering the inundation around the building footprint, results also indicated that the storm surge caused the largest percentage of flooding, followed by high-intensity rainfall. Whether from the perspective of the percentage of submerged length in the total perimeter of the buildings or the amount of damage, the storm surge undoubtedly caused a greater impact on the WWTP. Therefore, the storm surge poses a huge challenge to the Newtown  
Figure 3: (**a**) Land cover of sub-basin 133 in NYC, (**b–d**) inundation maps of SLOSH category 2 hurricane, a rainfall of 10.9 cm/h for 20 min, and sea level rise of 2.44 m (8 ft) in sub-basin 133.  
Creek WWTP. In future disaster prevention research and decision-making, this event should be given special attention.