---
marp: true
theme: riprap
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size: 16:9
title: Riprap. Citation-grounded flood-exposure briefings for any place in New York City.
description: ASCE NY State Convention, Albany, May 13, 2026
---
ASCE NY State Convention · Albany, NY · May 13, 2026
# Riprap
## Citation-grounded flood-exposure briefings for any place in New York City.
Speaker
Adam Munawar Rahman · IBM · MS CE, NYU
Invited by
Andrew Hicks
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00 · Learning objectives
# What you will take away.
After this session, you will be able to:
Describe a citation-grounded architecture for synthesizing multi-source flood evidence into auditable, site-specific narratives.
Identify where this approach is appropriate (screening, grant evidence, capital planning) and where it is not (hydraulic modeling, stamped deliverables).
Evaluate the guarantees and limitations of LLM-based evidence synthesis in civil engineering practice.
Apply the Five-Stone architecture to riverine, ice-jam, and dam-failure flooding.
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01 · The problem
# When you assess flood exposure, the evidence sits in eight or more places.
For a capital project, a grant application, a vulnerability assessment, or a property disclosure — the relevant evidence sits across eight or more disconnected primary sources. Synthesizing them into a citable narrative takes hours of GIS work per site.
Real evidence cards rendered by the live system · 442 East Houston Street, Manhattan.
CapstoneGranite 4.1 8B + Mellea rejection sampling · numerics_grounded · no_placeholder_tokens · citations_dense · citations_resolve · reroll until every claim cites its source → cited 4-section briefing
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04 · Demo
# Live demo.
“Hollis, Queens”
A neighborhood-scale briefing. NYC DEP and OEM planners use this shape of query when scoping where the next $30B stormwater priority site should land.
5.8 s
end-to-end
4 / 4
grounding checks every run
8+
primary public-record sources
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05 · Civic applications
# The civic case for civil engineers.
Grant evidence
HUD CDBG-DR and FEMA BRIC vulnerability assessments. Riprap auto-generates the per-NTA evidence section for each site in a program area. Citable, reproducible, open-source.
Capital project screening
NYC DEP Bluebelt expansion, NYCHA resilience hardening, MTA station prioritization, DOE school siting. Site-by-site evidence packages at the screening tier, before the hydraulic modeling budget is spent.
NY State Infrastructure Report Card
The 2026 report is in preparation. Riprap is the per-place evidence layer for the flood-exposure chapter of any future NY State infrastructure report — reproducible at every address.
Property disclosure compliance
NY’s March 2024 Property Condition Disclosure flood-risk amendment requires sellers to disclose flood history. Riprap is the citable narrative behind the disclosure — every claim sourced.
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06 · What Riprap is not.
# What Riprap is not.
The civil engineer carries the stamp. Riprap surfaces the evidence the engineer judges.
Not a hydraulic model
Riprap does not replace HEC-RAS, SWMM, or ICM. It synthesizes evidence from completed modeling work; it does not produce new flow or stage estimates. No substitute for a calibrated hydraulic model.
Not a stamped deliverable
The briefing is a starting point for a memo, not the memo itself. Professional judgment, field reconnaissance, and the engineer’s stamp are required for any actionable deliverable.
Not a substitute for site investigation
Microtopography is from 1 m USGS 3DEP LiDAR, appropriate for screening, not for design. Field reconnaissance, soil borings, and survey are not replaced.
Not a risk score
Riprap does not output a 1–10 or 1–100 number. Score-based tools (First Street, ClimateCheck, Jupiter) are different products for different audiences. Riprap is the evidence audit trail behind any such judgment.
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07 · Directions
# Where this goes from here.
The architecture is data-choice-specific, not code-specific.
Upstate NY flooding
The same five-Stone pattern for riverine, ice-jam, and dam-failure flooding. Different primary sources, same architecture.
Historical-event mode
Re-run the system against snapshot data from any past date. Calibration as a core feature.
Stones as standalone packages
Each Stone runs alone. Pull one without the full Riprap stack.
Cross-domain
The same pattern for transit, water, energy, and structural-condition reporting. Flood is the first domain.
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08 · How it was built
# The art of the possible.
Three days of AI-assisted development, on top of months of design thinking. Four foundation models. Three Apache-2.0 NYC fine-tunes trained on AMD MI300X for the AMD × lablab.ai Developer Hackathon (May 4–10, 2026).
Apache-2.0 end-to-end on public-record federal, state, and city data. No commercial APIs contacted at runtime.
Built in three days. Designed over months. The tools have shifted what one engineer can ship.
Foundation models
IBM Granite 4.1 8B (synthesizer) · IBM Granite Embedding 278M (RAG) · GLiNER (typed extraction) · vLLM on AMD MI300X
I am a software engineer, not a civil engineer. The system I just showed you is opinionated about what counts as evidence: citation-grounded, silent when uncertain, public-record only. But I am less sure about where it falls short of how a stamped engineering deliverable would need to behave.
Three questions for the room:
Where in your practice would a tool like this be useful, and where would it be a liability?
What evidence sources are you using that Riprap does not yet know about?
What would have to be true for a citation-grounded narrative tool to be trusted as a screening-tier deliverable?
