A flood-risk study for a low-lying coastal development should examine how rainfall, rivers, the sea or lagoon, and the drainage system interact. A drainage assessment based on rainfall alone can miss restrictions at outfalls or dependence on pumping.
STREAM uses the following scope checklist when discussing studies with developers, municipalities and engineering teams in Albania. It is a method guide, not a finding about a named parcel or a completed client contract.
Start with a verified elevation reference
Topography, channel beds, outfall inverts, pump levels and receiving-water observations must use compatible horizontal and vertical references. A low elevation shown on a regional map is a screening indication. Surveyed benchmarks and a documented datum are needed before concluding that a site is below sea level or selecting design levels.
Separate the flood mechanisms, then assess interaction
| Mechanism | What to establish |
|---|---|
| Local rainfall and runoff | Catchment boundaries, rainfall inputs, infiltration assumptions, storage and overland flow paths. |
| River or channel flooding | Upstream inflows, channel geometry, crossings, obstructions and floodplain connections. |
| Sea or lagoon influence | Receiving-water levels, timing, backwater effects and relevant coastal processes. |
| Drainage and pumping | Outfall levels, gates, conveyance, effective pump performance, storage and operational dependence. |
Compare meaningful system scenarios
Define a baseline and proposed-development condition. Where the site depends on pumping, consider agreed operational conditions and a reduced-capacity or outage scenario. High receiving-water levels can affect gravity drainage and pump discharge conditions. The joint timing of rainfall and receiving-water levels needs an explicit assumption; assigning the same return period to separate inputs does not establish the probability of their coincidence.
Choose modelling tools for the processes
Terrain, channel and drainage models should represent the mechanisms relevant to the decision. USACE documents rainfall inputs in HEC-RAS, but also identifies limitations in using it as a coastal model. Wave-driven processes may require suitable coastal methods and additional expertise. Software selection should follow the study question and available evidence.
What should the client receive?
- A source register separating measured information, estimates and assumptions.
- A scenario matrix and maps of relevant depth, extent, pathways or other agreed outputs.
- A description of drainage and pumping assumptions, model checks and sensitivity.
- A gap register and recommendations for survey, monitoring or further design.
For an initial scope, provide a site boundary, survey and datum information, drainage drawings, pumping records where available, historical flood evidence and the planning or design decision. See STREAM services and technical resources.
Technical source
USACE HEC-RAS 2D User’s Manual: Global Boundary Conditions. The checklist above is STREAM’s scope-planning guidance and does not imply USACE endorsement.
Discuss your project
Send the location, decision to be supported, available records and required timetable through our project enquiry page. Technical contact: Dr.-Ing. Klodian Zaimi, founder and Principal Technical Expert of STREAM Sh.p.k.
Prepared by STREAM. Reviewed on 2 November 2026. This guide helps define a study scope; site-specific conclusions require appropriate observations, modelling and technical review.