Rio Grande de Manati PR (Ciales) Feasibility Study (I)

April 2022


Rio Grande de Manati PR (Ciales) Feasibility Study (I)
Investigation (I)
Congressional District: Puerto Rico


The Municipality of Ciales, with population of 18,800, is located on the northern slopes of the Central Mountain Range of Puerto Rico, approximately 40 kilometers (25 miles) southwest of San Juan. The detailed study area is located at the northeast corner of the municipality and within its urban center with population of 2,600. Only the Dos Rios low income housing community (140 units), some commercial structures and the Municipal Sports Facilities are affected by floods at the confluence of Rio Grande de Manati and Rio Cialitos. There are two bridges, one over each river, within the detailed study area. The Rio Grande de Manati at Ciales has an approximate drainage area of 331 square kilometers (128 square miles) and flows north just east of the Dos Rios community. The Rio Cialitos has an approximate drainage area of 44 square kilometers (17 square miles) and flows northeast just south of the Dos Rios Community. Damages associated with flooding have been reported by the Municipality at least four times in the last thirty years.  Among the most damaging were the floods caused by hurricanes Hugo (1989), Hortense (1996), Georges (1998) and Maria (2017). In 1985, the Dos Rios community was flooded twice. In addition to property damages , a serious risk exists to the lives and wellbeing of those residing within the flood plain. Frequent flooding seriously impedes the socio-economic development of the community, as well. Previous flood damages reduction studies by the local sponsor resulted in a complete set of plans and specifications for the construction of a combination of levees, floodwalls, interior drainage facilities, and channel improvements. In 2010, the estimated construction cost of this project was $8.5 M; because of Puerto Rico’s financial, crisis funding for construction was never obtained.


Estimated Total Cost

Estimated Federal Cost

$ 14,823,000

$ 10,165,000

  1. P.L. 115-123: Bi-Partisan Budget Act of 2018, Supplemental:

Feasibility was funded under P.L. 115-123: Bi-Partisan Budget Act of 2018, Supplemental. The feasibility study was brokered to Pittsburgh District (LRP). LRP managed the project to include the funding and financial data.


  1. P.L. 117-43: Disaster Relief Supplemental Appropriations Act:

Total Work Plan (Construction)

Allocation for FY22

$ 14,823,000

$ 0


Puerto Rico Department of Natural and Environmental Resources (DNER)
P.O. Box 366147
San Juan, Puerto Rico 00936


The study is brokered to the Great Lakes and Ohio River Division (LRD).The Pittsburg District Project Delivery Team (PDT) held the Alternatives Milestone Meeting (AMM) on 24 Mar-2019. The next major milestone is the Tentatively Selected Plan scheduled for 29 Nov-2019. The Chief of Engineers’ report is scheduled for 09 Oct-2020. Prior to the AMM, FEMA and the PR Public Housing Authority informed the USACE of their decision to relocate the Dos Rios and Alturas de Ciales public housing in order to reduce flood risk of those living there. This will reduce the level or risk in the community and it will also change how USACE address the remaining risk, because part of the problem has already been addressed. Potential alternative will include non-structural alternatives such as relocations.