Councillors noted the Mid Richmond Drainage Study at their 20 October meeting in Casino (resolution 201026/8, moved by Cr Stephen Morrissey, seconded by Cr Sandra Humphrys, carried). They also resolved to do further detailed planning on mitigation options and to apply for funding. The study is four reports, one per town, prepared by Burchills Engineering Solutions and dated October 2026.
What the study found
The study deals with flash flooding from heavy rain falling on the towns themselves, not
the Richmond or Evans rivers, which the reports leave to the council’s regional flood
models. Its headline finding is the same for all four towns. In the officers’ words,
most of the existing underground drainage infrastructure reaches full capacity during a 39% Annual Exceedance Probability (AEP) rainfall event, equivalent to approximately a 1 in 2.5-year storm event
.
A 39 per cent AEP storm has a 39 per cent chance of happening in any given year. Beyond that,
water runs over roads, through yards and into low points.
Pipes full
About 1 in 2.5 years
the storm in which most of the underground network reaches capacity, in all four towns.
Checked against measured floods
No
no gauged streamflow or flood level data was available for any of the four towns.
Pipe and culvert blockage assumed
0 per cent
on the council’s advice, to match earlier modelling for Casino.
From the four Burchills design reports, sections 4 and 5, and the officers’ report at item 17.3 of the 20 October 2026 agenda.
Two of those settings cut in opposite directions. Each report says its model
has not been calibrated or validated against observed flood events
,
though the officers’ report says the council checked the outputs against community
feedback, customer requests, staff observations and flood records, and that
This process provided confidence that the modelling reasonably reflects observed stormwater flooding behaviour within each township.
And assuming no blockage shows the network at its best; the reports say it was chosen
to identify the network’s shortcomings when it is operating at capacity. The models
also leave out a rain storm arriving while the river is already high. For Broadwater, Coraki
and Evans Head, the climate scenario tested (one 1 per cent AEP storm late this century)
adds about 35 per cent to rainfall depth.
Where the water gathers
Each report picks out the places where the modelled 1 per cent AEP storm, the one with a one in 100 chance in any year, gets deepest or most hazardous. The deepest point the report gives for each place:
| Town | Location, as the report names it | Deepest, 1% AEP | Floors |
|---|---|---|---|
| Broadwater | Baraang Drive between Pine Tree Road and Fischer Street | about 600 mm | Above-floor flooding likely for a number of properties |
| Broadwater | Essex, Pitt, McDonald and George streets, around the new subdivision | about 1,000 mm | Above-floor flooding likely for a number of properties |
| Broadwater | Near the Rileys Hill Road and Baraang Drive intersection | about 1,000 mm | Above-floor flooding possible |
| Broadwater | Rileys Hill Road and Fletcher Street | about 500 mm, in the road reserve | |
| Coraki | Eastern end of Belmore Street | about 500 mm | |
| Coraki | Bridge Street between Grenfell and Adams streets | about 800 mm | Mostly raised houses; floor survey needed |
| Coraki | Block south-east of Adams and Bridge streets | about 600 mm, in the rear drain | |
| Coraki | Allwood and Martin streets | about 1,000 mm | Above-floor flooding likely for a number of properties |
| Coraki | Grenfell and Martin streets | about 700 mm | Above-floor flooding likely for a number of properties |
| Coraki | Minto Street and Queen Elizabeth Drive | about 1,000 mm, at a culvert inlet | Above-floor flooding likely for a number of properties |
| Evans Head | South of Pacific Crescent and Sunderland Street | under 600 mm; flow up to more than 2 m/s | |
| Evans Head | Cashmore and Cedar streets | about 600 mm | |
| Evans Head | Woodburn Street between Wattle and Cedar streets | about 500 mm | |
| Evans Head | Park Street between Booyong and Beech streets | about 800 mm | |
| Evans Head | Caravan park east of Park Street | 500 to 1,000 mm | |
| Evans Head | Myall, Woodburn, Coral and Cassia streets | about 1,000 mm | |
| Evans Head | Banksia Street and Bottlebrush Crescent | about 600 mm | |
| Evans Head | Ash and Beronia streets | about 500 mm | |
| Woodburn | Richmond Street east of Sussex Street | about 1,000 mm | |
| Woodburn | Richmond Street between Alfred and Sussex streets | about 1,000 mm | |
| Woodburn | Richmond and Duke streets | about 1,000 mm | |
| Woodburn | River Street and School Lane | about 500 mm | |
| Woodburn | Uralba and Cooper streets | about 900 mm |
Section 4.2 of each Burchills design report (Broadwater, Coraki, Evans Head, Woodburn, October 2026). Depths are the deepest local figure the report gives, often in a drain or road low point rather than a yard. A blank in the last column means the report makes no floor-level statement for that place, not that floors stay dry.
The floor-level warnings are the ones to read closely. For Baraang Drive, the Broadwater
report says It is likely that a number of properties experience above-floor flooding in this area during major storm events.
It says the same of the area around the new subdivision, whose design earthworks and 2025
drainage were built into the model. For Bridge Street in Coraki it is more cautious: the
houses there are generally raised on stumps, so
floor level survey is required to confirm above floor flooding
.
The reports also warn that their mapping rests on 2023 LiDAR and is no substitute
for a site-specific assessment of a single property.
The streets residents already report
None of this will surprise people on two of these streets. The council’s own Stormwater Drainage Service Review, dated 30 July 2026, counted more than 2,000 drainage requests from 2018 to early 2026 and listed repeat locations. The first two it names: Bridge Street, Coraki, with 41 requests, and Baraang Drive, Broadwater, with 32. Both are now mapped risk areas in the study. We set out that review, and the stormwater special rate it led to, in October.
it does not recommend specific infrastructure upgrades
What it does not do
The study is a map, not a works list. The officers’ report says further
investigation, concept design and cost-benefit work are needed before projects can be
progressed or funding considered, and that
there are no direct financial implications associated with noting the study
.
The council’s plan had already set it up that way: the officers’ report on the
revised budget says years 1 and 2 of the 2025-2029 Delivery Program were for flood risk plans
and stormwater modelling, and years 3 and 4 for seeking funding to implement drainage
solutions.
So what is in the budget now? The revised draft Operational Plan, endorsed for exhibition on the same night, lists the stormwater capital works for 2026-27 to 2029-30 street by street.
Evans Head, four years
$172,000
Coral Street ($40,000 in 2026-27) and three Cedar Street jobs from 2028-29.
Coraki and Broadwater, four years
$17,000 each
Yabsley Street and Richmond Terrace in Coraki; Rileys Hill Road and the Broadwater-Evans Head Road in Broadwater.
Woodburn, four years
No line
no job is listed under a Woodburn heading.
Stormwater Management capital works, draft Operational Plan including Financial Estimates 2026-2030, page 67. Four-year sums are our addition. The plan spells the Coraki street “Yablsey St”.
Those named jobs, $510,000 across the shire including $304,000 in Casino, are about a fifth of the four-year stormwater capital total of $2,718,885. The other $2,208,885 sits under “Renewals to be allocated”, so some of it may yet go to the Mid Richmond. The plan does not say where.
The money, and the vote on 20 October
The revised plan is the one carrying the proposed stormwater special rate. In it, stormwater revenue goes from $209,373 in 2026-27 to $709,079 in 2027-28, the first year of the proposed rate. The stormwater service’s operating deficit narrows from $1,065,821 to $600,585, while the capital works total barely moves, from $660,000 to $659,685. The council’s report says the extra revenue would be restricted to stormwater drainage, asset renewal and service improvements.
Not every councillor wanted the plans out. Cr John Walker, seconded by Cr Lyndall Murray, moved to defer the special rate for two years and not exhibit the revised plans. That was lost 2-5, and the Mayor’s amendment to exhibit them carried 5-2, Crs Murray and Walker against.
Our view
This is useful, overdue work, and the council deserves credit for linking all four reports in full from the agenda. But it leaves a gap a ratepayer will notice. The council is proposing a new stormwater rate on urban properties, and it now holds a street-level map of where water gathers in the Mid Richmond. The draft budget on exhibition does not yet join the two: a year of special-rate revenue mostly narrows the service’s deficit, and the named works for four towns come to a little over $200,000 in four years. Residents of all four towns, and of the Coraki and Broadwater streets where the reports place their floor-level warnings, are entitled to ask which of their streets the money would reach, and when.
Dates and how to comment
- 30 July 2026 Stormwater Drainage Service Review lists the repeat complaint locations.
- 20 October 2026 Council notes the drainage study and endorses the revised long term financial plan and operational plan for exhibition.
- 4 November 2026 Feedback on the stormwater special rate closed.
- November 2026 meeting Feedback reported to council before it decides whether to tell IPART it intends to apply.
- 30 November 2026 Submissions close on the revised draft Long Term Financial Plan 2026-36 and draft Operational Plan 2026-2030.
- February 2027 Special rate applications due to IPART.
Submissions on the revised plans go in writing through the form on the council’s exhibition page; for more information the council gives 02 6660 0300. The four study reports are linked from the 20 October agenda; the council says the reports and mapping will be made publicly available.
How we sourced this
The study’s findings, locations, depths, floor-level statements, limitations and assumptions are from the four Burchills design reports, read in full in their text sections (the maps are in each report’s appendices, which we did not read map by map). The summary findings, verification statement and budget position are from the officers’ reports at items 17.3 and 18.1 of the 20 October 2026 agenda; the resolutions, movers and votes are from the unconfirmed minutes. Capital works and stormwater revenue, expenditure and deficit figures are from the draft Operational Plan on exhibition; the sums by town and the shares are our arithmetic. The complaint counts are from the July 2026 service review. The Evans Head report’s conclusion describes a “south-western basin” and “northern paddock areas” in the same words as the Coraki report’s, features its own body does not describe; we relied on the body text. The minutes give the number 201026/9 to two different resolutions, so we have not quoted a number for the exhibition vote. We have not contacted the council.
Sources
The working. AI read the documents and drafted this story, under rules people set and answer for, working from the primary sources below. 7 quotations were compared by machine with our saved copies of the sources, and matched exactly. How we work.
- Richmond Valley Council, Agenda, Ordinary Council Meeting, 20 October 2026 (PDF, read 5 November 2026): item 17.3, Mid Richmond Stormwater Drainage Study; item 18.1, Stormwater Services Special Rate Variation proposal.
- Richmond Valley Council, Minutes, Ordinary Council Meeting, 20 October 2026 (PDF, unconfirmed, read 5 November 2026): resolution 201026/8 and the votes on item 18.1.
- Burchills Engineering Solutions for Richmond Valley Council, Mid Richmond Drainage Study, Broadwater, Design Report (PDF, 133 pages, October 2026, read 5 November 2026).
- Burchills Engineering Solutions for Richmond Valley Council, Mid Richmond Drainage Study, Coraki, Design Report (PDF, 141 pages, October 2026, read 5 November 2026).
- Burchills Engineering Solutions for Richmond Valley Council, Mid Richmond Drainage Study, Evans Head, Design Report (PDF, 190 pages, October 2026, read 5 November 2026).
- Burchills Engineering Solutions for Richmond Valley Council, Mid Richmond Drainage Study, Woodburn, Design Report (PDF, 140 pages, October 2026, read 5 November 2026).
- Richmond Valley Council, Draft Proposed Operational Plan including Financial Estimates 2026-2030 (PDF, 120 pages, read 5 November 2026): Stormwater Management service budget, page 31, and capital works, page 67.
- Richmond Valley Council, Draft Long Term Financial Plan and Operational Plan on Exhibition (exhibition page, published 28 October 2026, read 5 November 2026): closing date and how to make a submission.
- Richmond Valley Council, Stormwater Drainage Service Review 2026 (PDF, 30 July 2026, read 8 October 2026): customer request hotspots.
Live on one of these streets, or read the mapping differently? Tell us and we will check it against the council’s own papers and log the outcome.